Federal Register, Volume 76 Issue 12 (Wednesday, January 19, 2011)

[Federal Register Volume 76, Number 12 (Wednesday, January 19, 2011)]
[Rules and Regulations]
[Pages 3212-3305]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-547]

[[Page 3211]]

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Part II

Department of Transportation

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National Highway Traffic Safety Administration

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49 CFR Parts 571 and 585

Federal Motor Vehicle Safety Standards, Ejection Mitigation; Phase-In
Reporting Requirements; Incorporation by Reference; Final Rule

Federal Register / Vol. 76, No. 12 / Wednesday, January 19, 2011 /
Rules and Regulations

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 571 and 585

[Docket No. NHTSA-2011-0004]
RIN 2127-AK23

Federal Motor Vehicle Safety Standards, Ejection Mitigation;
Phase-In Reporting Requirements; Incorporation by Reference

AGENCY: National Highway Traffic Safety Administration (NHTSA), U.S.
Department of Transportation (DOT).

ACTION: Final rule.

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SUMMARY: This final rule establishes a new Federal Motor Vehicle Safety
Standard No. 226, ``Ejection Mitigation,'' to reduce the partial and
complete ejection of vehicle occupants through side windows in crashes,
particularly rollover crashes. The standard applies to the side windows
next to the first three rows of seats, and to a portion of the cargo
area behind the first or second rows, in motor vehicles with a gross
vehicle weight rating (GVWR) of 4,536 kilogram (kg) or less (10,000
pounds (lb) or less). To assess compliance, the agency is adopting a
test in which an impactor is propelled from inside a test vehicle
toward the windows. The ejection mitigation safety system is required
to prevent the impactor from moving more than a specified distance
beyond the plane of a window. To ensure that the systems cover the
entire opening of each window for the duration of a rollover, each side
window will be impacted at up to four locations around its perimeter at
two time intervals following deployment.
The agency anticipates that manufacturers will meet the standard by
modifying existing side impact air bag curtains, and possibly
supplementing them with advanced glazing. The curtains will be made
larger so that they cover more of the window opening, made more robust
to remain inflated longer, and made to deploy in both side impacts and
in rollovers. In addition, after deployment the curtains will be
tethered near the base of the vehicle's pillars or otherwise designed
to keep the impactor within the boundaries established by the
performance test. This final rule adopts a phase-in of the new
requirements, starting September 1, 2013.
This final rule advances NHTSA's initiatives in rollover safety and
also responds to Section 10301 of the Safe, Accountable, Flexible,
Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU).
That section directs NHTSA to initiate and complete rulemaking to
reduce complete and partial ejections of vehicle occupants from
outboard seating positions, considering various ejection mitigation
systems.

DATES: Effective date: The date on which this final rule amends the
Code of Federal Regulations (CFR) is March 1, 2011. The incorporation
by reference of certain publications listed in the standard is approved
by the Director of the Federal Register as of March 1, 2011.
Petitions for reconsideration: If you wish to petition for
reconsideration of this rule, your petition must be received by March
7, 2011.
Compliance dates: This final rule adopts a phase-in of the new
requirements. The phase-in begins on September 1, 2013. By September 1,
2017, all vehicles must meet the standard, with the exception of
altered vehicles and vehicles produced in more than one stage, which
are provided more time to meet the requirements. Manufacturers can earn
credits toward meeting the applicable phase-in percentages by producing
compliant vehicles ahead of schedule, beginning March 1, 2011 and
ending at the conclusion of the phase-in.

ADDRESSES: If you wish to petition for reconsideration of this rule,
you should refer in your petition to the docket number of this document
and submit your petition to: Administrator, National Highway Traffic
Safety Administration, 1200 New Jersey Avenue, SE., West Building,
Washington, DC 20590.
The petition will be placed in the docket. Anyone is able to search
the electronic form of all documents received into any of our dockets
by the name of the individual submitting the comment (or signing the
comment, if submitted on behalf of an association, business, labor
union, etc.). You may review DOT's complete Privacy Act Statement in
the Federal Register published on April 11, 2000 (Volume 65, Number 70;
Pages 19477-78).
For access to the docket to read background documents or comments
received, go to http://www.regulations.gov and follow the online
instructions for accessing the docket. You may also visit DOT's Docket
Management Facility, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001 for on-line access to
the docket.

FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may contact
Mr. Louis Molino, NHTSA Office of Crashworthiness Standards, telephone
202-366-1740, fax 202-493-2739. For legal issues, you may contact Ms.
Deirdre Fujita, NHTSA Office of Chief Counsel, telephone 202-366-2992,
fax 202-366-3820.
You may send mail to these officials at the National Highway
Traffic Safety Administration, U.S. Department of Transportation, 1200
New Jersey Avenue, SE., West Building, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Safety Need
III. Congressional Mandate
IV. Summary of the NPRM
V. Summary of the Comments
VI. How the Final Rule Differs From the NPRM
VII. Foundations for This Rulemaking
a. Advanced Glazing
b. Full Window Opening Coverage Is Key
c. Comparable Performance in Simulated Rollovers and Component-
Level Impact Tests
d. Advantages of a Component Test Over a Full Vehicle Dynamic
Test
VIII. Availability of Existing Curtains
IX. Existing Curtains
a. Existing Curtains Tested to Proposed Requirements
b. Field Performance
X. Response to Comments and Agency Decisions
a. Impactor Dimensions and Mass
1. NPRM
2. Comments
3. Agency Response
b. Measurement Plane and Displacement Limit (100 mm)
1. NPRM
2. Comments
3. Agency Response
c. Times and Speed at Which the Headform Impacts the
Countermeasure
1. NPRM on Time Delay (Ejections Can Occur Both Early and Late
in the Rollover Event)
i. Comments on Time Delay
ii. Agency Response
2. Speed at Which the Headform Impacts the Countermeasure
i. Comments on Impact Speed
ii. Agency Response
d. Target Locations
1. Why We Are Focusing on Side Windows and Not Other Openings
2. Why We Are Focusing on the Side Windows Adjacent to First
Three Rows
i. First Three Rows
ii. Method of Determining 600 mm Behind Seating Reference Point
(SgRP)
iii. Increasing 600 mm Limit for Vehicles With One or Two Rows
of Seats
3. Answers to Questions About Method for Determining Three-Row
Area
e. How We Are Testing the Ability of These Side Windows To
Mitigate Ejections
1. What is a ``window opening''?
i. 50 mm Inboard of the Glazing

[[Page 3213]]

ii. Conducting the Test With Various Items Around the Window
Opening
iii. Removing Flexible Gasket Material
iv. Testing With Weather Stripping in Place
v. Metal Dividers in Glazing
2. How We Determine Impactor Target Locations in an Objective
and Repeatable Manner
i. Testing in ''Any'' Location
ii. Methodology
iii. Reorienting the Targets
iv. Suppose Even With Rotating the Headform the Vehicle Has No
Target Locations
v. Decision Not To Test Target of Greatest Displacement
vi. Reconstitution of Targets
f. Glazing Issues
1. Positioning the Glazing
2. Window Pre-Breaking Specification and Method
g. Test Procedure Tolerances
h. Impactor Test Device Characteristics
i. Readiness Indicator
j. Other Issues
1. Rollover Sensors
2. Quasi-Static Loading
3. Full Vehicle Test
4. Minor Clarifications to the Proposed Regulatory Text
k. Practicability
l. Applicability
1. Convertibles
2. Original Roof Modified
3. Multi-Stage Manufacture of Work Trucks
4. Other
m. Lead Time and Phase-In Schedules; Reporting Requirements
XI. Costs and Benefits
XII. Rulemaking Analyses and Notices

I. Executive Summary

This final rule establishes a new Federal Motor Vehicle Safety
Standard (FMVSS) No. 226, ``Ejection Mitigation,'' to reduce the
partial and complete ejection of vehicle occupants through side windows
in crashes, particularly rollover crashes. Countermeasures installed to
meet this rule will also reduce the number of complete and partial
ejections of occupants in side impacts. This final rule responds to
section 10301 of the Safe, Accountable, Flexible, Efficient
Transportation Equity Act: A Legacy for Users,'' (SAFETEA-LU), Public
Law 109-59 (Aug. 10, 2005; 119 Stat. 1144), which requires the
Secretary of Transportation to issue an ejection mitigation final rule
reducing complete and partial ejections of occupants from outboard
seating positions.
Addressing vehicle rollovers is one of NHTSA's highest safety
priorities. In 2002, NHTSA conducted an in-depth review of rollovers
and associated deaths and injuries and assessed how this agency and the
Federal Highway Administration (FHWA) could most effectively improve
safety in this area.\1\ The agency formulated strategies involving
improving vehicle performance and occupant behavior, and with the FHWA
taking the lead, improving roadway designs. Vehicle performance
strategies included crash avoidance and crashworthiness programs, and
included four wide-ranging initiatives to address the rollover safety
problem: prevent crashes, prevent rollovers, prevent ejections, and
protect occupants who remain within the vehicle after a crash. Projects
aimed at protecting occupants remaining in the vehicle during a
rollover included improved roof crush resistance and research on
whether seat belts could be made more effective in rollovers.
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\1\ The assessment was carried out by one of four Integrated
Project Teams (IPTs) formed within NHTSA, whose recommendations
culminated in the agency's priority plan, ``NHTSA Vehicle Safety
Rulemaking and Supporting Research: 2003-2006'' (68 FR 43972; July
18, 2003) http://www.nhtsa.dot.gov/cars/rules/rulings/PriorityPlan/FinalVeh/Index.html. The IPT Report on Rollover was published in
June 2003 (68 FR 36534, Docket 14622).
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A major undertaking implementing the first two initiatives was
completed in 2007 when NHTSA adopted a new FMVSS No. 126 (49 CFR
571.126), ``Electronic Stability Control Systems,'' to require
electronic stability control (ESC) systems on passenger cars,
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating (GVWR) of 4,536 kg (10,000 lb) or less (72 FR 17236,
April 6, 2007, Docket NHTSA-2007-27662). ESC systems use automatic
computer-controlled braking of the individual wheels of a vehicle to
assist the driver in maintaining control in critical driving situations
in which the vehicle is beginning to lose directional stability at the
rear wheels (spin out) or directional control at the front wheels (plow
out). Because most loss-of-control crashes culminate in the vehicle's
leaving the roadway--an event that significantly increases the
probability of a rollover--preventing single-vehicle loss-of-control
crashes is the most effective way to reduce deaths resulting from
rollover crashes.\2\ The agency estimates that when all vehicles (other
than motorcycles) under 4,536 kg GVWR have ESC systems, the number of
deaths each year resulting from rollover crashes would be reduced by
4,200 to 5,500. From 2001 to 2007, there were more than 10,000 deaths
in light vehicle rollover crashes. Rollover deaths have decreased
slightly in 2008 (9,043) and 2009 (8,267), as have fatalities in all
crash types.
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\2\ NHTSA estimates that the installation of ESC will reduce
single-vehicle crashes of passenger cars by 34 percent and single
vehicle crashes of sport utility vehicles (SUVs) by 59 percent.
NHTSA further estimates that ESC has the potential to prevent 71
percent of the passenger car rollovers and 84 percent of the SUV
rollovers that would otherwise occur in single-vehicle crashes.
NHTSA estimates that ESC would save 5,300 to 9,600 lives and prevent
156,000 to 238,000 injuries in all types of crashes annually once
all light vehicles on the road are equipped with ESC systems.
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While ESC systems will avoid many of the roadway departures that
lead to rollover, vehicle rollovers will continue to occur.\3\ Once a
rollover occurs, vehicle crashworthiness characteristics play a crucial
role in protecting the occupants. According to agency data, occupants
have a much better chance of surviving a crash if they are not ejected
from their vehicles.
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\3\ NHTSA has developed a Final Regulatory Impact Analysis
(FRIA) for this final rule that discusses issues relating to the
target population and the potential costs, benefits and other
impacts of this regulatory action. The FRIA is available in the
docket for this final rule and may be obtained by downloading it or
by contacting the Docket Management facility at the address provided
at the beginning of this document.
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Concurrent with the agency's work on ESC, NHTSA began work on the
third initiative on rollover safety, pursuing the feasibility of
installing crashworthiness safety systems to mitigate occupant
ejections through side windows in rollovers (``ejection mitigation'').
Major strides on this third initiative were realized in 2007 when the
agency published a final rule that incorporated a dynamic pole test
into FMVSS No. 214, ``Side impact protection'' (49 CFR 571.214)
(``Phase 1 FMVSS No. 214 rulemaking'').\4\ The pole test, applying to
motor vehicles with a GVWR of 4,536 kg or less, requires vehicle
manufacturers to provide side impact protection for a wide range of
occupant sizes and over a broad range of seating positions. To meet the
pole test, manufacturers are installing new technologies capable of
improving head and thorax protection in side crashes, i.e., side
curtain air bags and torso air bags.
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\4\ 72 FR 51908; September 11, 2007, Docket No. NHTSA-29134;
response to petitions for reconsideration, 73 FR 32473, June 9,
2008, Docket No. NHTSA-2008-0104, 75 FR 12123, March 15, 2010,
Docket No. NHTSA-2010-0032. On August 10, 2005, the ``Safe,
Accountable, Flexible, Efficient Transportation Equity Act: A Legacy
for Users,'' (SAFETEA-LU), Public Law 109-59 (Aug. 10, 2005; 119
Stat. 1144) was enacted, to authorize funds for Federal-aid
highways, highway safety programs, and transit programs, and for
other purposes. Section 10302(a) of SAFETEA-LU directed the
Secretary to complete the FMVSS No. 214 rulemaking by July 1, 2008.
The September 11, 2007 final rule completed the rulemaking specified
in section 10302(a). NHTSA estimates that the September 11, 2007
final rule will save 311 lives annually.
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Today's final rule launches a new phase in occupant protection and
ejection mitigation. It builds on and

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improves existing technology while achieving cost efficiency and does
so expeditiously. This final rule enhances the side curtain air bag
systems installed pursuant to the FMVSS No. 214 side impact rulemaking.
Side curtain air bags \5\ will be made larger to cover more of the
window opening, more robust to remain inflated longer, enhanced to
deploy in side impacts and in rollovers, and made not only to cushion
but also made sufficiently strong to keep an occupant from being fully
or partially ejected through a side window. The side curtain air bags
required by this rule will be designed to retain the occupant
regardless of whether the occupant had his or her window glazing up,
down, or partially open, and even when the glazing is destroyed during
the rollover crash.
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\5\ In this document, this countermeasure is referred to as an
``ejection mitigation side curtain air bag,'' ``side curtain air
bag,'' ``air bag curtain,'' ``rollover curtain,'' or simply
``curtain.'' This countermeasure is designed to deploy in a rollover
crash. The same side curtain air bag meeting FMVSS No. 226 can be
used to meet the ejection mitigation requirements of FMVSS No. 214
with the addition of a rollover sensing system to deploy the side
curtain air bag in a rollover.
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The NPRM upon which this final rule is based was published on
December 2, 2009 (74 FR 63180, Docket No. NHTSA-2009-0183). Materials
underlying the development of this rule have been placed in that docket
and in a research and development docket created in 2006 (Docket No.
NHTSA-2006-26467).
Rollover crashes can be complex and unpredictable. At this time
there is no conventional rollover scenario or test representative of
real-world rollover crashes that can be used in a dynamic test to the
agency's satisfaction to evaluate the performance of ejection
mitigation countermeasures. Yet, this final rule achieves ejection
mitigation benefits notwithstanding the absence of a dynamic procedure.
Agency research has found that full coverage of the side windows is a
key element to mitigating ejection. This standard adopts a component
test that assures there is full coverage of the side window to diminish
the potential risk of the windows as ejection portals and that assesses
ejection mitigation safety systems for as long in the crash event as
the risk of ejection reasonably exists.
The test uses a guided impactor to assess the ability of the
countermeasure (e.g., a curtain system) to mitigate ejections in
different types of rollover and side impact crashes involving different
occupant kinematics. The test has been carefully designed to represent
occupant to vehicle interactions in a dynamic rollover event. The
impact mass is based on the mass imposed by a 50th percentile male's
head and upper torso on the window opening during an occupant ejection.
The mass of the impactor, 18 kilograms (kg) (40 lb), is propelled at
points around the window's perimeter with sufficient kinetic energy to
assure that the ejection mitigation countermeasure is able to protect a
far-reaching range of occupants in real world crashes.
In the test, the countermeasure must retain the linear travel of
the impactor such that the impactor must not travel 100 millimeters
(mm) beyond the location of the inside surface of the vehicle glazing.
This displacement limit serves to control the size of any gaps forming
between the countermeasure (e.g., the ejection mitigation side curtain
air bag) and the window opening, thus reducing the potential for both
partial and complete ejection of an occupant.
To evaluate the performance of the curtain to fully cover potential
ejection routes, the impactor will typically target four specific
locations per side window adjacent to the first three rows of the
vehicle. Impacting four targets around the perimeter of the opening
assures that the window will be covered by the countermeasure
(curtain), while imposing a reasonable test burden. Small windows will
be tested with fewer targets.
Computer modeling has shown that ejections can occur early and late
in the rollover event. In the standard's test procedure, the ejection
mitigation side countermeasure will be tested at two impact speeds and
at two different points in time, to ensure that the protective system
will retain the occupant from the relatively early through the late
stages of a rollover.
The times at which the impacts will occur are data-driven and
related to our goal of containment of occupants both early and late in
rollovers. Crash data show that slightly less than half of all fatal
complete ejections occurred in crashes with 5 or fewer quarter-turns.
Film analysis of vehicles that rolled 5 or fewer quarter-turns in
staged rollover tests indicates that it took about 1.5 seconds for the
vehicles to roll once completely. A vehicle rolling 11 quarter-turns
had a maximum roll time of 5.5 seconds. Data from the National
Automotive Sampling System (NASS) Crashworthiness Data System (CDS)
show that rollovers with eleven or fewer quarter-turns account for
about 98 percent of rollovers with fatal complete ejection.\6\ The
standard replicates these crash dynamics with the two impacts of the
headform. The first impact will be at 20 kilometers per hour (km/h)
(12.4 miles per hour (mph)), 1.5 seconds after deployment of the
curtain. The second impact will be at 16 km/h (9.9 mph), 6 seconds
after deployment of the curtain. The 20 km/h and 16 km/h tests
replicate the forces that an occupant can impart to the curtain during
the rollover event as well as during side impacts.
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\6\ This is based on 2000-2009 NASS data. The 1988--2005 NASS
data reported in the NPRM showed that 93 percent of rollovers with
fatal complete ejections had 11 or fewer quarter-turns.
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Under today's final rule, vehicle manufacturers must provide
information to NHTSA upon request that describes the conditions under
which ejection mitigation air bags will deploy. There is no presently
demonstrated need for us to specify in the standard the conditions
dictating when the sensors should deploy; field data indicate that
rollover sensors are overwhelmingly deploying effectively in the real
world. We will keep monitoring field data to determine whether future
regulatory action is needed in this area.
This chapter in occupant protection will achieve tremendous
benefits at reasonable costs. We estimate that this rule will save 373
lives and prevent 476 serious injuries per year (see Table 1 below).
The cost of this final rule is approximately $31 per vehicle (see Table
2). The cost per equivalent life saved is estimated to be $1.4 million
(3 percent discount rate)-$1.7 million (7 percent discount rate) (see
Table 3 below). Annualized costs and benefits are provided in Table 4.

Table 1--Estimated Benefits
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Fatalities.............................................. 373
Serious Injuries........................................ 476
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Table 2--Estimated Costs*
[2009 economics]
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Per Vehicle............................... $31.
Total Fleet (16.5 million vehicles)....... $507 Million
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* The system costs are based on vehicles that are equipped with an FMVSS
No. 214 curtain system. According to vehicle manufacturers'
projections made in 2006, 98.7 percent of Model Year (MY) 2011
vehicles will be equipped with curtain bags and 55 percent of vehicles
with curtain bags will be equipped with a rollover sensor.

Table 3--Cost per Equivalent Life Saved
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7% Discount
3% Discount rate rate
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$1.4M..................................................... $1.7M
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Table 4--Annualized Costs and Benefits
[In millions of $2009 dollars]
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Annualized
Annual costs benefits Net benefits
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3% Discount Rate................................................ $507M $2,279M $1,773
7% Discount Rate................................................ 507M 1,814M 1,307
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Accompanying today's final rule is a Final Regulatory Impact
Analysis (FRIA) analyzing the costs, benefits, and other impacts of
this final rule, and a technical report the agency has prepared that
presents a detailed analysis of engineering studies, and other
information supporting the final rule. Both documents have been placed
in the docket for this final rule. The documents can be obtained by
contacting the docket by the means specified at the beginning of this
document or by downloading them at www.regulations.gov.

II. Safety Need

Rollover crashes are a significant and a particularly deadly safety
problem. As a crash type, rollovers are second only to frontal crashes
as a source of fatalities in light vehicles. Data from the last 10
years of Fatal Analysis Reporting System (FARS) files (2000-2009\7\)
indicate that frontal crash fatalities have averaged about 11,600 per
year, while rollover fatalities have averaged 10,037 per year. In 2009,
35 percent of all fatalities were in light vehicle rollover crashes.
The last 10 years of data from the National Automotive Sampling System
(NASS) General Estimates System (GES) indicate that an occupant in a
rollover is 14 times more likely to be killed than an occupant in a
frontal crash.\8\
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\7\ These data are updated from the 1998 to 2007 FARS data
reported in the NPRM.
\8\ The relative risk of fatality for each crash type can be
assessed by dividing the number of fatalities in each crash type by
the frequency of the crash type. The frequency of particular crash
types is determined by police traffic crash reports (PARs).
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Ejection is a major cause of death and injury in rollover crashes.
According to 2000-2009 FARS data, on average 47 percent of the
occupants killed in rollovers were completely ejected from their
vehicle. During this time period, there were 358 fully ejected
occupants killed for every 1,000 fully ejected occupants in rollover
crashes, as compared to 14 of every 1,000 occupants not fully ejected
occupants killed.\9\ A double-pair comparison from the last ten years
of FARS data show that avoiding complete ejection is associated with a
64 percent decrease in the risk of death.\10\
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\9\ The data combines partially-ejected and un-ejected occupants
together, because partial ejection is sometimes difficult to
determine and the PAR-generated FARS data may not be an accurate
representation of partially-ejected occupant fatalities.
\10\ ``Incremental Risk of Injury and Fatality Associated with
Complete Ejection,'' NHTSA, 2010 (see the docket for this final
rule).
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The majority of rollover crashes involve the vehicle rolling over
two quarter-turns or less. However, the distribution of ejected
occupants who are seriously injured (maximum abbreviated injury scale
(MAIS) 3+) or killed is skewed towards rollovers with a higher number
of quarter-turns. According to NASS Crashworthiness Data System (CDS)
data of occupants exposed to a rollover crash from 2000 to 2009, half
of all fatal complete ejections occurred in crashes with six or more
quarter-turns.
Most occupants are ejected through side windows. In developing the
target population estimates for this final rule we found that
annualized injury data from 1997 to 2008 NASS CDS and fatality counts
adjusted to the annual average from FARS for these same years\11\
indicate that ejection through side windows is the greatest contributor
to the ejection problem.\12\ There were 16,272 MAIS 1-2 injuries, 5,209
MAIS 3-5 injuries, and 6,412 fatalities resulting from ejections
through the side windows adjacent to the first three rows.
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\11\ The target population estimate for the NPRM used 1997 to
2005 FARS data. The estimate for this final rule is based on an
additional three years of data.
\12\ In our data analysis for the NPRM to determine ejection
routes, we assumed that an ejection route coding of ``rear'' in NASS
CDS meant a second row window and that ``other'' glazing meant third
and higher row side window ejections. The assumption was based on
the coding of seat position in NASS. Since then, we have determined
that an occupant coded as ejected through a ``rear'' window did not
necessarily go through the second row window. Similarly, the coding
of ``other'' glazing was determined not necessarily to mean third
and higher row. Thus, for this final rule, for cases coded as
ejected through ``rear'' or ``other'' glazing, we assume that the
ejection was through a second row window in the following
circumstances: the occupant was seated in the first two rows of a
vehicle, or the vehicle was a convertible, two-door sedan, or four-
door sedan (i.e., these are vehicles without a third row or cargo
area). If an occupant was coded as seated in the third or higher row
and was coded as ejected through a rear window or ``other'' glazing,
we used the NASS Case Query System to undertake a hard copy review.
We determined ejection routes in this manner for 41 unweighted rear
window cases and 17 unweighted ``other'' glazing cases. A hard copy
review of the ``other'' glazing cases showed that 9 were known 3rd
row side window ejections, but five cases were miscoded. Four were
actually backlight ejections and one was a sunroof ejection. The
known 3rd row ejections were recoded as ``Row 3 Window'' ejections.
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Table 5 below shows the MAIS 1-2, MAIS 3-5, and fatality
distribution of ejected occupants by 11 potential ejection routes.\13\
The ``Not Glazing'' category captures ejected occupants that did not
eject through a glazing area or the roof (perhaps a door or an area of
vehicle structure that was torn away during the crash). Roof ejections
have been separated into ``Roof Panel or Glazing'' and ``Roof Other.''
The former groups sunroofs, t-tops and targa-tops into a single
category, whether made of glazing or having a sheet metal skin. The
latter combines convertibles, modified roofs, camper tops and removable
roofs. No distinction could be made as to whether these roof structures
were open or closed prior to ejection.
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\13\ All crash types are included, but the counts are restricted
to ejected occupants who were injured.

Table 5--Occupant Injury and Fatality Counts by Ejection Route in All Crash Types
[Annualized 1997-2008 NASS and FARS]
----------------------------------------------------------------------------------------------------------------
Ejection route MAIS 1-2 MAIS 3-5 Fatal
----------------------------------------------------------------------------------------------------------------
Windshield................................................ 1,517 1,400 1,078
First-Row Windows......................................... 14,293 4,980 5,589
Second-Row Windows........................................ 1,700 641 796

[[Page 3216]]

Third-Row Windows......................................... 279 88 27
Fourth-Row Windows........................................ 0 0 39
Fifth-Row Window.......................................... 0 0 7
Cargo Area Rear of Row 2.................................. 342 17 52
Backlight................................................. 1,621 1,364 495
Roof Panel or Glazing..................................... 1,000 367 324
Roof Other................................................ 420 105 81
Multiple Windows.......................................... 0 19 0
Not Glazing............................................... 2,848 2,207 1,814
-----------------------------------------------------
Subtotals: ................ ................ ................
Rows 1-3.......................................... 16,272 5,709 6,412
4th, 5th Row and Cargo............................ 342 17 98
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Total................................................. 24,020 11,188 10,302
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Table 6, below, provides the percentage of the total at each injury
level. The injuries and fatalities resulting from ejections through the
first three rows of windows constitute 68 percent of MAIS 1-2 injuries,
51 percent of MAIS 3-5 injuries, and 62 percent of all ejected
fatalities.

Table 6--Occupant Injury and Fatality Percentages by Ejection Route in All Crash Types
[Annualized 1997-2008 NASS and FARS]
----------------------------------------------------------------------------------------------------------------
Ejection route MAIS 1-2 MAIS 3-5 Fatal
----------------------------------------------------------------------------------------------------------------
Windshield................................................ 6.3% 12.5% 10.5%
First-Row Windows......................................... 59.5% 44.5% 54.2%
Second-Row Windows........................................ 7.1% 5.7% 7.7%
Third-Row Windows......................................... 1.2% 0.8% 0.3%
Fourth-Row Windows........................................ 0.0% 0.0% 0.4%
Fifth-Row Window.......................................... 0.0% 0.0% 0.1%
Cargo Area Rear of Row 2.................................. 1.4% 0.2% 0.5%
Backlight................................................. 6.8% 12.2% 4.8%
Roof Panel or Glazing..................................... 4.2% 3.3% 3.1%
Roof Other................................................ 1.7% 0.9% 0.8%
Multiple Windows.......................................... 0.0% 0.2% 0.0%
Not Glazing............................................... 11.9% 19.7% 17.6%
-----------------------------------------------------
Subtotals: ................ ................ ................
Rows 1-3.......................................... 67.7% 51.0% 62.2%
4th, 5th Row and Cargo............................ 1.4% 0.2% 1.0%
-----------------------------------------------------
Total................................................. 100.0% 100.0% 100.0%
----------------------------------------------------------------------------------------------------------------

Since the countermeasure covering side window openings will be made
more effective in preventing ejections, this rulemaking will also
reduce the number of complete and partial ejections of occupants in
side impacts. These benefits go beyond those achieved in the rulemaking
adopting an oblique pole test into FMVSS No. 214 (Phase 1 FMVSS No. 214
rulemaking) because a side air bag installed to meet FMVSS No. 214 is
not necessarily wide or robust enough to effectively contain occupants
in certain side impacts. In fact, NHTSA found that FMVSS No. 214's
requirements could be met by a seat-mounted head/torso side air bag or
a side head protection curtain air bag together with a seat-mounted or
door-mounted torso bag. Further, FMVSS No. 214's pole test does not
apply to rear seats. In short, FMVSS No. 214 does not require the large
curtain needed for full coverage of side window openings.
Accordingly, this ejection mitigation safety standard will reduce
the number of partial and complete ejections of occupants in side
impacts. The Phase 1 FMVSS No. 214 rulemaking included reduction of
partial ejections of adults (age 13+ years) through side windows in
side impacts, but did not include complete ejections. The Phase 1 side
impact rulemaking also did not include any impact where a rollover was
the first event. In addition, benefits were only assumed in the Phase 1
FMVSS No. 214 rulemaking for side impact crashes with a change in
velocity ([Delta]V) between 19.2 and 40.2 km/h (12 to 25 mph) and
impact directions from 2 to 3 o'clock and 9 to 10 o'clock. The side
curtain air bags used to meet FMVSS No. 226's ejection mitigation
requirements will directly prevent many ejection-induced injuries and
fatalities in side impacts that could not be saved by a side air bag
that minimally complies with FMVSS No. 214.

Target Population

In general, the target population for this ejection mitigation
final rule is composed of occupants injured or killed by ejection from
the first three rows of side windows in vehicles to which the standard
applies. Later in the preamble, we discuss some slight adjustments made
concerning occupants ejected through cargo area window openings.

[[Page 3217]]

The target population does not include occupants ejected in all crash
types, but rather is restricted to ejections that occur in crashes
involving rollovers and some types of planar only side impacts. The
limitation on side impacts, change in velocity ([Delta]V), and certain
occupants in those side impacts is necessary to not count benefits
anticipated by FMVSS No. 214.
Tables 7-9 provide the counts and/or percentages of the injured and
killed side window (rows 1-3) ejected occupants by the window row they
were ejected through. These data are restricted to rollover crashes and
side impacts in the relevant [Delta]V range (target population type
crashes).
Tables 7 and 8 show the ejection degree and restraint condition for
occupants in the first three rows of target population type crashes.
Among the side windows, the first row windows provide the ejection
route for most of the injured and killed occupants. The greatest number
of fatally ejected occupants (3,837) went through the first row window.
This represents 88 percent of all side window ejected fatalities.
Similarly, 3,979 (89 percent) MAIS 3-5 and 10,017 (87 percent) MAIS 1-2
injured occupants went through the row 1 windows. Within each row, the
greatest number of fatal and MAIS 3-5 occupants were completely ejected
and unbelted. There were 2,623 fatally injured (59 percent) and 2,269
MAIS 3-5 injured (50 percent) occupants who were unbelted and
completely ejected through the row 1 windows.

Table 7--Distribution of First 3 Rows of Side Window Ejected Occupants by Ejection Row and Injury Level by Ejection Degree and Belt Use, In Target
Population Type Crashes
[Annualized 1997-2008 NASS and FARS]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Row 1 Row 2 Row 3
Ejection degree Belted --------------------------------------------------------------------------------------------------
MAIS 1-2 MAIS 3-5 Fatal MAIS 1-2 MAIS 3-5 Fatal MAIS 1-2 MAIS 3-5 Fatal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Complete.......................... Yes.............. 95 29 54 139 78 5 0 8 0
Complete.......................... No............... 3,501 2,269 2,623 782 309 421 95 54 23
Partial........................... Yes.............. 4,345 1,097 484 43 32 38 109 0 0
Partial........................... No............... 2,076 584 675 103 80 123 4 0 0
--------------------------------------------------------------------------------------------------
Total......................... ................. 10,017 3,979 3,837 1,067 499 587 207 62 23
--------------------------------------------------------------------------------------------------------------------------------------------------------

Table 8--Distribution of First 3 Rows of Side Window Ejected Occupants by Ejection Row and Injury Level by Ejection Degree and Belt Use, as a Percentage
of Totals at each Injury Level, in Target Population Type Crashes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Row 1 Row 2 Row 3
Ejection degree Belted --------------------------------------------------------------------------------------------------
MAIS 1-2 MAIS 3-5 Fatal MAIS 1-2 MAIS 3-5 Fatal MAIS 1-2 MAIS 3-5 Fatal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Complete.......................... Yes.............. 1% 1% 1% 1% 2% 0% 0% 0% 0%
Complete.......................... No............... 31% 50% 59% 7% 7% 9% 1% 1% 1%
Partial........................... Yes.............. 38% 24% 11% 0% 1% 1% 1% 0% 0%
Partial........................... No............... 18% 13% 15% 1% 2% 3% 0% 0% 0%
--------------------------------------------------------------------------------------------------
Total......................... ................. 87% 89% 88% 86% 9% 11% 13% 2% 1%
--------------------------------------------------------------------------------------------------------------------------------------------------------

Table 9 shows the ejection degree and vehicle type for occupants in
the first three rows of target population type crashes. The greatest
numbers of fatalities result from occupants completely ejected from
passenger cars. These account for 28 percent of the total fatalities.
Combining partial and complete ejections, cars account for 43
percent of fatalities and 42 percent of MAIS 3 to 5 injuries. Pickup
trucks and sport utility vehicles (SUVs) combined account for 50
percent of fatalities and 54 percent of MAIS 3 to 5 injuries. Since the
early 1990s, the SUV segment has provided an increasing proportion of
rollover fatalities. SUVs represented approximately 16 percent of
fatalities in 1997, and nearly 27 percent in 2008. Vans comprise 7
percent of the fatalities and 4 percent of the MAIS 3-5 ejections.

Table 9--Distribution of Fatalities and Injuries of First 3 Rows Side Window Ejected Occupants By Vehicle Type
[Annualized 1997--2008 NASS and FARS]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vehicle MAIS 1-2 MAIS 3-5 Fatal MAIS 1-2 MAIS 3-5 Fatal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Complete Ejections......................... Car.......................... 1,158 928 1,239 10% 20% 28%
PU........................... 1,236 812 793 11% 18% 18%
SUV.......................... 1,881 858 907 17% 19% 20%
Van.......................... 324 147 188 3% 3% 4%
Other........................ 12 2 0 0% 0% 0%
-----------------------------------------------------------------------------
Subtotal..................... 4,612 2,747 3,127 41% 61% 70%
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 3218]]

Partial Ejections.......................... Car.......................... 1,429 971 660 13% 21% 15%
PU........................... 2,515 375 190 22% 8% 4%
SUV.......................... 1,590 402 350 14% 9% 8%
Van.......................... 1,133 44 103 10% 1% 2%
Other........................ 13 0 17 0% 0% 0%
-----------------------------------------------------------------------------
Subtotal..................... 6,680 1,793 1,320 59% 39% 30%
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Ejections............................ Car.......................... 2,588 1,899 1,899 23% 42% 43%
PU........................... 3,750 1,187 983 33% 26% 22%
SUV.......................... 3,471 1,260 1,257 31% 28% 28%
Van.......................... 1,457 192 291 13% 4% 7%
Other........................ 25 2 17 0% 0% 0%
-----------------------------------------------------------------------------
Total........................ 11,292 4,540 4,447 100% 100% 100%
--------------------------------------------------------------------------------------------------------------------------------------------------------

In summary, for the most part, the target population for this
ejection mitigation final rule is composed of occupants injured or
killed in an ejection from the first three rows of side windows in
vehicles to which the standard applies. The target population does not
include the population addressed by the Phase 1 FMVSS No. 214
rulemaking, and does not include persons benefited by the installation
of ESC systems in vehicles. (We assume that all model year 2011
vehicles and thereafter will be equipped with ESC, see FMVSS No. 126.)
As adjusted for ESC, the target population for this ejection mitigation
rulemaking is reduced to 1,392 fatalities, 1,410 MAIS 3-5 injuries and
4,217 MAIS 1-2 injuries. This target population constitutes 23 percent
of fatally-injured occupants ejected through a side window, 27 percent
of MAIS 3-5 injured, and 23 percent of MAIS 1-2 injured side window-
ejected occupants.\14\
---------------------------------------------------------------------------

\14\ When discussing the target population in this preamble, we
will typically mean the pre-ESC adjusted values. We will
specifically state when we are referring to an ESC-adjusted target
population.
---------------------------------------------------------------------------

III. Congressional Mandate

This final rule responds to section 10301 of SAFETEA-LU, which
requires the Secretary of Transportation to issue an ejection
mitigation final rule reducing complete and partial ejections of
occupants from outboard seating positions. Section 10301 amended
Subchapter II of chapter 301 (49 U.S.C. Chapter 301, National Traffic
and Motor Vehicle Safety Act) (``Vehicle Safety Act'') to add section
30128. Section 10301, paragraph (a), directs the Secretary to initiate
rulemaking proceedings, for the purpose of establishing rules or
standards that will reduce vehicle rollover crashes and mitigate deaths
and injuries associated with such crashes for motor vehicles with a
GVWR of not more than 10,000 pounds. Paragraph (c) directs the
Secretary to initiate a rulemaking proceeding to establish performance
standards to reduce complete and partial ejections of vehicle occupants
from outboard seating positions and that, in formulating the standards,
the Secretary shall consider various ejection mitigation systems.\15\
---------------------------------------------------------------------------

\15\ Paragraph (c) states that the Secretary shall issue a final
rule under this paragraph by October 1, 2009. Paragraph (e) states
that if the Secretary determines that the subject final rule
deadline cannot be met, the Secretary shall notify and provide
explanation to the Senate Committee on Commerce, Science, and
Transportation and the House of Representatives Committee on Energy
and Commerce of the delay. On September 24, 2009, the Secretary
notified Congress that the final rule will be delayed until January
31, 2011.
---------------------------------------------------------------------------

NHTSA's final rule fulfills the statutory mandate of section 10301
of SAFETEA-LU to issue an ejection mitigation final rule reducing
complete and partial ejections of occupants from outboard seating
positions. We have considered various ejection mitigation systems,
including advanced glazing,\16\ and have made appropriate decisions
based on that analysis. At the time of its implementation this final
rule will reduce fatality ejected occupants by about one third \17\ and
completes a decisive stage in the agency's rollover crashworthiness
program.
---------------------------------------------------------------------------

\16\ One type of advanced glazing systems, usually referred to
as laminated glazing, has a multi-layer construction typically with
three primary layers. There is usually a plastic laminate bonded
between two pieces of glass. Advanced glazing was considered in the
1990s to have potential for use in ejection mitigation.
\17\ This fatality reduction does not double-count benefits from
ESC and the recent FMVSS No. 214 upgrade.
---------------------------------------------------------------------------

A few glazing manufacturers, a glazing manufacturers' association,
and two consumer groups expressed a view in their comments to the NPRM
that the rulemaking will fall short of the statutory mandate unless the
final rule ensured that windows will not allow any openings larger than
two inches to form during a rollover event (as a consequence, such a
requirement would encourage the use of advanced glazing). These
commenters also believed that SAFETEA-LU directed NHTSA to address
ejections through sun roofs, moon roofs,\18\ and rear windows in this
standard. We address these comments in detail in later sections of this
preamble.
---------------------------------------------------------------------------

\18\ For this document, we refer to movable and fixed roof
panels made of glazing as ``moon roofs'' and movable panels having a
sheet metal exterior as ``sun roofs.'' We refer to both as roof
portals.
---------------------------------------------------------------------------

With regard to the general assertion that this rulemaking does not
meet SAFETEA-LU, we cannot agree. As part and parcel of good
governance, all safety standards must be reasonable and appropriate. In
addition, in adding section 30128 to the Vehicle Safety Act, SAFETEA-LU
specifically requires us to issue an ejection mitigation final rule in
accordance with the criteria of that Act. The Vehicle Safety Act
requires each motor vehicle safety standard to be practicable, meet the
need for motor vehicle safety, and be stated in objective terms. (49
U.S.C. 30111(a).) We must also consider whether the standard is
reasonable, practicable, and appropriate for the particular type of
motor vehicle or motor vehicle equipment for which it is prescribed.
(49 U.S.C. 30111(b)(3).)
This final rule requires protective barriers at side windows, the
ejection

[[Page 3219]]

portals through which 62 percent of occupants are fatally ejected in
all crash types. We did not adopt the suggestions in the comments of
the glazing manufacturers that could have bolstered increased use of
advanced glazing in side windows because we did not find a safety need
supporting the approaches. For back windows (backlight) and roof
portals, we found that not enough was known to appropriately evaluate
the costs, benefits and practicability of the requirements, at this
time, including the lack of a viable test procedure. (Fatal ejections
through the back light and roof portals account for 4.8 and 3.9 percent
of fatal ejections in all crash types.) An appropriate test procedure
that would assess ejection potential through portals on the vehicle's
roof is also unknown.
In formulating this final rule, NHTSA considered various ejection
mitigation systems in accordance with section 10301 of SAFETEA-LU. We
sought to adopt performance measures that were design-neutral and
performance-oriented so as to provide substantial flexibility to
vehicle manufacturers in developing or enhancing ejection mitigation
countermeasures that meet the requirements of the standard. To
illustrate, the headform test procedure was originally developed in the
advanced glazing research program and can be used to assess the
performance of many different types of countermeasures at the side
windows. The final rule recognizes the beneficial effect advanced
glazing can have and permits the use of fixed glazing to achieve the
performance criteria specified in the standard. At the same time,
however, NHTSA determined after considering real-world field data on
advanced glazing that movable advanced glazing alone would not be a
satisfactory ejection mitigation countermeasure for side window
openings, given that 31 percent of front seat ejections are through
windows that were partially or fully rolled down, and given that it is
not unusual for advanced glazing to be heavily damaged and rendered
ineffective in a rollover crash. Accordingly, the standard does not
permit use of movable glazing alone to meet the requirements of the
standard. Movable glazing may be used in the high speed test, but it
must be used in conjunction with a deployable safety system that will
mitigate ejection throughout the stages of a rollover event, such as an
ejection mitigation side curtain air bag.
In directing us to consider various ejection mitigation systems,
there is indication that Congress envisioned us focusing on ejections
through side windows. At the time of enactment of SAFETEA-LU, Congress
was aware of the agency's past work on advanced side glazing and of our
ejection mitigation research program. Congress was aware that side
curtain air bags were showing strong potential as an ejection
mitigation countermeasure and that we had redirected research and
rulemaking efforts from advanced side glazing to developing
performance-based test procedures for an ejection mitigation
standard.\19\
---------------------------------------------------------------------------

\19\ ``Ejection Mitigation Using Advanced Glazing, Final
Report,'' NHTSA, August 2001, Docket 1782-22. See also, NHTSA's
termination of an advance notice of proposed rulemaking on advanced
glazing (67 FR 41365, June 18, 2002), infra.
---------------------------------------------------------------------------

In addition, in the legislative history on section 10301, section
7251 of the Senate bill which the Conference committee adopted
(Conference Report of the Committee of Conference on H.R. 3, Report
109-203, 109th Congress, 1st Session) directed the Secretary to include
consideration of ``advanced side glazing, side air curtains, and side
impact air bags'' (emphases added) in establishing the standard. We
believe that Congress wanted us to take into account the knowledge
gained from our past work on side ejections in formulating this
standard, which we have, building on our knowledge gained from the
advanced side glazing and rollover crashworthiness programs.
It would take a longer time than the timeframe allowed by SAFETEA-
LU to address fatal ejections through the back light and roof portals.
In contrast to the side window research program, which started in the
early 1990s, the agency had no research and development foundation upon
which requirements for the back light and roof portal could be based.
Much is unknown regarding a test procedure, effectiveness of current
designs, method of anchoring advanced glazing to the backlight frame
and roof portal, and possible other countermeasures and their costs.
The agency believed that Congress intended us to build on the knowledge
already attained and issue this final rule addressing side window
ejections, which account for 62 percent of all fatal occupant ejections
in all crashes, as quickly as possible, rather than delay this final
rule to venture into areas that account for 8.7 percent of those fatal
ejections.
In sum, we developed this final rule to meet the criteria of
section 10301 of SAFETEA-LU and the Vehicle Safety Act, making sure
that it is a performance standard that reduces complete and partial
ejections from outboard seating positions and that it is reasonable,
practicable, and appropriate, that it meets the need for safety and is
stated in objective terms. Further, ensuring that the final rule is
consistent with Executive Order 12866, we have adopted requirements
that not only maximize the benefits of a cost-effective approach to
ejection mitigation, but do so with an approach that saves over 370
lives. This final rule wholly implements the instructions of our
statutory and administrative directives.

IV. Summary of the NPRM

NHTSA issued a proposal for a new FMVSS No. 226 and proposed the
standard apply to passenger cars, multipurpose passenger vehicles,
trucks and buses with a GVWR of 4,536 kg or less. We proposed that the
side windows next to the first three rows of seats be subject to
performance requirements requiring the vehicle to have an ejection
mitigation countermeasure that would prevent an 18 kg (40 lb) headform
from moving more than 100 mm (4 inches) beyond the zero displacement
plane of each window when the window is impacted. Each side window
would be impacted at up to four locations around its perimeter at two
energy levels and time intervals following deployment. The first impact
was proposed to be at 24 km/h, 1.5 seconds after deployment of the
ejection mitigation side curtain air bag, assuming there was one
present (``24 km/h-1.5 second test''), and the second impact was
proposed to be at 16 km/h, at 6 seconds after deployment (``16 km/h-6
second test''). The NPRM proposed to allow windows of advanced glazing
to be in position during the test, but pre-broken, using a prescribed
method, to reproduce the state of glazing in an actual rollover crash.
The NPRM discussed proposals for: (a) The impactor dimensions and
mass; (b) the displacement limit; (c) impactor speed and time of
impact; and (d) target locations. We also discussed: (e) glazing
issues; (f) test procedure tolerances; (g) test device characteristics;
and other issues, such as a requirement for a readiness indicator.
The NPRM did not specifically require a rollover sensor to deploy
the curtains or attributes that the sensor must meet; manufacturers
currently provide sensors with their ejection mitigation curtains and
NHTSA believed they will continue to provide a sensor enabling
deployment regardless of an express requirement to do so. With regard
to applicability, the agency tentatively decided in the NPRM not to
exclude convertibles but requested comments on this issue and on the
applicability of the standard to other

[[Page 3220]]

types of vehicles, e.g., police vehicles with security partitions.
Except for limited line and multistage manufacturers, the proposed
lead time was the first September 1 three years from the date of
publication of a final rule. The requirements were proposed to be
phased in over a four-year period, with 20 percent of each
manufacturer's vehicles manufactured during the first production year
required to meet the standard, 40 percent manufactured during the
second year required to meet the standard, 75 percent of vehicles
manufactured during the third year required to meet the standard, and
all vehicles (without use of advanced credits) manufactured on or after
the fourth year required to meet the standard. It was proposed that
limited line and multistage manufacturers would not have to achieve
full compliance until one year after the phase-in is completed.
Accompanying the NPRM was a Preliminary Regulatory Impact Analysis
(PRIA) analyzing the potential impacts of the proposed ejection
mitigation requirements, and a technical analysis prepared by the
agency that presented a detailed analysis of engineering studies, and
other information supporting the NPRM (``Technical Analysis in Support
of a Notice of Proposed Rulemaking Ejection Mitigation''). Both
documents were placed in the docket for the NPRM (Docket No. NHTSA-
2009-0183).

V. Summary of the Comments

NHTSA received 35 comments on the NPRM. Comments were received from
motor vehicle manufacturers through their associations and
individually, from air bag and glazing equipment suppliers (also
through their associations and individually), and from consumer and
insurance groups, and individuals.
The Alliance of Automobile Manufacturers (Alliance) \20\ stated
that it was generally supportive of many aspects of the NPRM, such as
the use of a linear headform impactor for evaluating rollover deployed
side curtains and the decision not to specify a protocol for testing
rollover sensors. However, the commenter disagreed with the proposed
performance requirements, believing that they are overly stringent and
may unnecessarily force the development of air bag systems that could
have adverse unintended consequences. The commenter stated that seat
belt use is the most effective countermeasure for ejection mitigation.
The Alliance stated its belief that there should be only one test at 16
km/h and at 3.4 seconds, with an excursion limit of 150 mm measured
from a plane tangent to the exterior of the vehicle. The Alliance also
stated its belief that the standard should not apply to convertibles
and to vehicles with partitions, for practicability reasons. Further,
the commenter asked for an additional year of lead time, and that
vehicles with a GVWR greater than 2,722 kg (6,000 lb) should have a
compliance date that is one year after the 100 percent phase-in date
for completed vehicles with a GVWR of 2,722 kg or less. The Alliance
also had technical comments on specific aspects of the test procedure.
---------------------------------------------------------------------------

\20\ The Alliance member companies are BMW Group, Chrysler
Group, Ford Motor Company, General Motors, Jaguar Land Rover, Mazda,
Mercedes-Benz USA, Mitsubishi Motors, Porsche, Toyota, and
Volkswagen (VW).
---------------------------------------------------------------------------

The Alliance's member companies commenting on the NPRM reiterated
the views of the Alliance, with some expounding on the following
matters of particular interest to them. General Motors (GM) stated that
the Alliance's suggested compliance date and phase-in schedule could be
met assuming that NHTSA adopts the modifications of the test procedure
identified by the Alliance and excludes convertibles and vehicles with
partitions. Ford commented that side glazing retention in real-world
rollover crashes is random and unpredictable and expressed the belief
that FMVSS No. 226 should be focused on rollover-activated side curtain
technology because these devices are designed to deploy regardless of
side glazing status in a rollover (e.g., retained, up, down or
partially open) or construction of the glazing. Mercedes raised
concerns about the difficulties larger vans such as the Sprinter would
have in meeting the requirements and asked for additional lead time for
vehicles over 8,500 lb GVWR. Porsche discussed the long lifecycles for
its sports cars and asked that manufacturers be allowed to use credits
earned for early compliance through the end of the 100 percent phase-in
year. Various manufacturers expressed technical views or had questions
about specific aspects of the test procedure.
The Association of International Automobile Manufacturers Technical
Affairs Committee \21\ (AIAM) stated that it ``supports the agency's
basic approach in the proposed ejection mitigation standard'' but is
``concerned that there may be unintended consequences if test criteria
establish unnecessary high levels of energy for the test impactor.''
AIAM said that high test impact speeds could require the use of stiffer
side curtain air bags or advanced glazing of increased rigidity to meet
the specified displacement limit. ``Such consequences may increase the
risk of head/neck injuries.'' AIAM urged the agency to consider whether
the impactor energy specifications may be reduced to a level equivalent
to 180 Nm (corresponding to a 16 km/h test). The commenter believed
that convertibles should be excluded from the standard for
practicability reasons and also suggested that certain classes of
vehicle could be excluded from the high speed requirement due to
vehicle characteristics that can dissipate the energy of occupants in
rollovers, such as vehicles having high ``belt-lines'' (e.g., sports
cars that seat the occupants low relative to the window openings). AIAM
asked for an additional year of lead time prior to the start of the
phase-in period and asked that advanced credits be allowed to meet the
100 percent stage of the phase-in. AIAM also commented on specific
aspects of the test procedure and supported GM's suggested procedure
for measuring impactor displacement from a plane tangent to the
vehicle's exterior.
---------------------------------------------------------------------------

\21\ AIAM Technical Affairs Committee members are American Honda
Motor Company (Honda), American Suzuki Motor Corp., Aston Martin
Lagonda of North America, Ferrari North America, Hyundai Motor
America (Hyundai), Isuzu Motor America, Kia Motors America, Maserati
North America, Nissan North America, Peugeot Motors of America,
Subaru of America, ADVICS North America, Delphi Corporation, Denso
International America, and Robert Bosch Corporation.
---------------------------------------------------------------------------

AIAM members commenting on the NPRM generally reiterated AIAM's
views, with some separately raising issues of individual concern. Honda
stated its belief that with an energy level of 200 joules (J), occupant
ejection mitigation can be balanced with occupant protection without
unintended adverse consequences to occupant protection. The commenter
suggested the test procedure consist of one test at 17 km/h with a 3.0
second time delay. Honda agreed with the proposed 100 mm displacement
limit, but suggested that displacement along a line normal to the
actual window at the center of each target impact point should not
exceed 100 mm. Nissan suggested the agency adopt a 20 km/h test instead
of the proposed 24 km/h test. In their individual comments, various
vehicle manufacturers asked for clarification of or changes to
particular aspects of the proposed test procedure.
Organizations representing specialized manufacturers commented on
the NPRM. Vehicle Services Consulting, Inc. (VSC) \22\ supported the

[[Page 3221]]

NPRM, but asked that convertibles be excluded from the standard. VSC
also asked for clarification of regulatory text applying to small
volume manufacturers. The National Truck Equipment Association (NTEA)
\23\ requested that NHTSA exclude from the ejection mitigation standard
work trucks built in two or more stages, particularly those with
partitions, and vehicles with alterations to the floor height.
---------------------------------------------------------------------------

\22\ VSC states: ``Vehicle Services Consulting, Inc. assists
numerous small volume vehicle manufacturers with US certification-
related matters.''
\23\ NTEA describes itself as a ``trade association representing
distributors and manufacturers of multi-stage produced, work related
trucks, truck bodies and equipment.''
---------------------------------------------------------------------------

Air bag supplier groups commented in favor of the NPRM. Takata
Corporation, a manufacturer of air bags and other motor vehicle
equipment, stated that it supports NHTSA's goal to establish a new
FMVSS to reduce the partial and complete ejection of occupants in
rollover crashes.\24\ However, Takata expressed concern about the
effectiveness of applying the ejection mitigation standard to
convertibles at this time. TRW, a manufacturer of vehicle safety
systems, and the Automotive Occupant Restraints Council (AORC) \25\
supported the agency's proposal in general, but suggested that all
windows should be tested down or removed regardless of whether the
glazing is laminated since motorists occasionally drive with their
windows open. TRW and AORC also expressed concern about applying the
ejection mitigation requirements to convertibles. Each of these
commenters had detailed feedback on and suggestions for improving the
proposed test procedures.
---------------------------------------------------------------------------

\24\ Takata also submitted information to NHTSA's ejection
mitigation research docket (NHTSA-2006-26467) indicating that
meeting the proposed performance requirements in non-convertibles
would be practicable.
\25\ AORC describes itself as a non-profit organization whose
mission is to promote automotive safety through education and
technology. Its membership consists of safety system manufacturers
and their suppliers.
---------------------------------------------------------------------------

Glazing manufacturers and suppliers commenting on the NPRM
generally supported the objectives and overall structure of the
proposed standard, but a number had the view that the agency fell short
of the congressional mandate of section 10301 of SAFETEA-LU, in that
roof glazing and backlight areas were not being regulated by the new
standard. Many of these groups also desired a reduction in the
performance limit, some by 50 percent (i.e., a displacement limit of 50
mm). Many of the groups commented that all windows should be tested in
the up (closed) position and several objected to the pre-test breaking
procedure for glazing as being excessive and suggested changes to it,
such as eliminating the specification to pre-break the interior surface
of the glazing. Many of these glazing supplier groups requested a
shorter lead time and phase-in period.
Consumer groups Public Citizen (PC) and Advocates for Highway and
Auto Safety (Advocates) commented on the NPRM. PC stated that the NPRM
is flawed because it does not address occupant ejections through the
roof and because the cost-benefit analysis is ``devised with the same
misleading approach to determining a target population that NHTSA has
used in other rollover rulemakings.'' PC suggested NHTSA establish a
performance requirement that would encourage the dual use of laminated
glazing and side curtain air bags, but stated that NHTSA should not
permit laminated glazing in vehicles not equipped with side curtain air
bags. PC suggested that the phase-in schedule should begin and end one
model year earlier than proposed. The commenter also was critical that
``the agency has not taken a comprehensive, whole vehicle approach to
reducing fatalities in rollover crashes.''
Advocates stated its belief that NHTSA interpreted SAFETEA-LU too
narrowly by addressing occupant ejection only through side windows and
not through side doors, tailgates, windshields, backlights, or sun
roofs. Advocates suggested that roofs can be strengthened and occupant
ejection reduced through the use of advanced glazing and that NHTSA
should promote pre-crash automated window closure to ensure that
vehicles with advanced glazing would be in the windows-up position.
Advocates supported ``mandatory anti-ejection countermeasures to be
applied at all designated seating positions, not just for outboard
occupants in the first, second, and third rows,'' including all
occupant positions in the rear seats of 15-passenger vans. Advocates
believed that the 100 mm proposed displacement limit should be 50 mm
and that areas outside of the target zones should be tested. The
commenter was concerned about the proposed time intervals for the
impactor tests \26\ and desired performance requirements for rollover
air curtain sensors. The commenter believed that manufacturers would
only need a two-year lead time and a three-year phase-in period to meet
the proposed requirements.
---------------------------------------------------------------------------

\26\ Advocates was concerned that ``no sustained inflation is
tested between the 1.5 and 6 second tests, when excursion could
exceed the 4 inch maximum required by the proposed standard.''
---------------------------------------------------------------------------

The Insurance Institute for Highway Safety (IIHS) said it supported
the NPRM because the commenter believed that the rulemaking is likely
to result in all passenger vehicles being equipped with side curtain
air bags that deploy in rollover crashes. However, IIHS stated that the
proposed 100 mm excursion limit may be overly restrictive. IIHS also
stated that the agency should provide an incentive to manufacturers to
equip vehicles with laminated side glazing.
Several individuals responded in general support of the NPRM and
with several suggestions. National Forensic Engineers, Inc. supported
the use of laminated glazing in side windows to supplement side curtain
air bags. Stephen Batzer and Mariusz Ziejewski, and Byron Bloch, stated
that the standard should apply to vehicles above 4,536 kg, to daylight
openings adjacent to every designated seating position and to the
windshield, sunroof and backlight, and supported the use of laminated
glazing. Batzer and Ziejewski believed that a 10 mph impact would be
sufficient. Bloch urged the agency to evaluate ejection mitigation
through a dynamic full vehicle rollover test.

VI. How the Final Rule Differs From the NPRM

The more important changes from the NPRM are listed in this section
and explained in detail later in this preamble. Changes more minor in
significance (e.g., changes that clarify test procedures) are not
listed below but are discussed in the appropriate sections of this
preamble.
i. The high speed impact test, performed at 1.5 seconds after
ejection mitigation side curtain air bag deployment, will have an
impact velocity of 20 km/h instead of 24 km/h. After evaluating the
comments to the NPRM, the agency reanalyzed the test data upon which
the impact speed proposed in the NPRM was based, analyzed the new
testing conducted since the NPRM, and considered all submitted
information. Based on this analysis, we agree to decrease the impact
test speed to 20 km/h, as suggested by Nissan in its comment, which
results in 278 joules (J) of impact energy. This energy value is well
supported and more representative of the energy the ejection
countermeasure will typically be exposed to in the field, particularly
in rollovers. All target locations in each window opening will be
subject to the high speed test, performed at 1.5 seconds after ejection
mitigation side curtain air bag deployment (``20 km/h-1.5 second
test''), and to the low speed 16 km/h test

[[Page 3222]]

performed 6 seconds after deployment (``16 km/h-6 second test'').
ii. If necessary, the headform and targets will be rotated by 90
degrees to a horizontal orientation if this results in more impact
locations than the vertical orientation (to a maximum of four target
locations). For long narrow windows, popular in many late model
vehicles, very limited target coverage of the opening is achieved if
the target is kept in the vertical orientation. It did not make sense
to exclude windows from being subject to full ejection mitigation
protection simply because the headform could not fit when oriented
vertically.
iii. The standard does not permit the use of movable advanced
glazing as the sole means of meeting the displacement limit of the
standard. In addition, the 16 km/h-6 second test must be performed
without the use of advanced glazing for movable windows. Field data
indicates that even when initially up, movable advanced glazing may be
destroyed and made ineffective as a countermeasure beyond the initial
phase of a rollover. Therefore, the final rule will require that if a
vehicle has movable advanced glazing as part of the ejection
countermeasure, the 16 km/h-6 second test will be performed with the
glazing retracted or removed from the window opening. This approach
will assure a reasonable level of safety when side glazing is rolled
down or when the severity of the rollover damages or destroys the
effectiveness of the glazing, and still encourages the use of advanced
glazing as a countermeasure to supplement the vehicle's performance in
meeting the 20 km/h-1.5 second test.
iv. The window opening for cargo areas behind the 1st and 2nd row
will be impacted. If there is a side window opening in a cargo area
behind the 1st row of a single row vehicle or behind the 2nd row of a
two-row vehicle, this final rule will extend coverage to those cargo
areas behind the 1st and 2nd rows of vehicles. The area of side window
openings in a cargo area will be bounded by a transverse plane 1,400 mm
behind the seating reference point (SgRP) of the rearmost seat in the
1st row of a single row vehicle or behind the SgRP of the rearmost seat
in the 2nd row of a two-row vehicle. Field data found that cargo area
ejections behind a 2nd row were similar in frequency to 3rd row
ejections. Such cargo area coverage is cost effective and is not any
more challenging than 3rd row coverage.
v. Minor changes were made in the definition of and procedure for
determining the window opening. The final rule increases the lateral
distance defining the window opening from 50 to 100 mm. We have
examined interior trim components, such as panels covering the vehicle
pillars and found that relevant surfaces can be more than 50 mm from
the inside of the window glazing and that these trim components can be
difficult to remove.
vi. The final rule slightly modifies the glazing pre-breaking
procedure by using a 75 mm offset pattern. (We disagree with the
comments that stated the pre-breaking procedure should be deleted or
should be restricted to four points on the glazing. We believe the pre-
breaking procedure is necessary to recreate the damage that will likely
occur in the field.)
vii. Convertibles are excluded from this standard. Also excluded
are law enforcement vehicles, correctional institution vehicles, taxis
and limousines with a fixed security partition separating the 1st and
2nd or 2nd and 3rd rows, if the vehicle is a multistage or altered
vehicle.
viii. The final rule has a 2-year lead time period, with 25 percent
of each manufacturer's vehicles manufactured during the first
production year required to meet the standard, 50 percent manufactured
during the second year required to meet the standard, 75 percent of
vehicles manufactured during the third year required to meet the
standard, and 100 percent of vehicles manufactured on or after the
fourth year required to meet the standard. The final rule allows
manufacturers to use advanced credits to meet the phase-in percentages,
including advanced credits in the last year (100 percent year) of the
phase-in schedule.
ix. Characteristics of the guided linear impactor with the 18 kg
headform and the associated propulsion mechanism were refined to assure
sufficient repeatability and reproducibility of the test. The impactor
used in research tests was originally constructed in the advanced
glazing program of the 1990s. We have reduced the maximum allowable
dynamic coefficient of friction of the test device by a factor of 5,
from 1.29 (old impactor) to 0.25 (new impactor). The device has been
made less flexible along its shaft and thus better able to maintain its
orientation as it interacts with ejection countermeasures.

VII. Foundations for This Rulemaking

This section discusses knowledge and insights we gained from past
research on ejection mitigation safety systems which underlie many of
the decisions we made in forming this final rule.

a. Advanced Glazing

In formulating this final rule, NHTSA considered various ejection
mitigation systems in accordance with section 10301 of SAFETEA-LU. One
of the considered systems was advanced side glazing. In the 1990s,
NHTSA closely studied advanced glazing as a potential ejection
mitigation countermeasure \27\ but terminated an advance notice of
proposed rulemaking on advanced glazing in 2002 (67 FR 41365, June 18,
2002). The termination was based on our observation that advanced
glazing produced higher neck shear loads and neck moments than impacts
into tempered \28\ side glazing. In addition, the estimated incremental
cost for installing ejection mitigation glazing in front side windows
ranged from over $800 million to over $1.3 billion, based on light
vehicle annual sales of 17 million units in the 2005-2006 timeframe.
Also, because side curtain air bags were showing potential as an
ejection mitigation countermeasure, NHTSA decided to redirect its
research and rulemaking efforts toward developing performance-based
test procedures for an ejection mitigation standard.\29\
---------------------------------------------------------------------------

\27\ Ejection mitigation glazing systems have a multi-layer
construction with three primary layers. There is usually a plastic
laminate bonded between two pieces of glass.
\28\ Tempered glass is made from a single piece of specially
treated sheet, plate, or float glass possessing mechanical strength
substantially higher than annealed glass. When broken at any point,
the entire piece breaks into small pieces that have relatively dull
edges as compared to those of broken pieces of annealed glass. (See
FMVSS No. 205, ``Glazing Materials,'' incorporating by reference
standard ANSI/SAE Z26.1-1996.)
\29\ ``Ejection Mitigation Using Advanced Glazing, Final
Report,'' NHTSA, August 2001, Docket No. NHTSA-1996-1782-22.
---------------------------------------------------------------------------

Elements from the advanced glazing program underlie a substantial
part of today's final rule. The headform and the test procedure were
originally developed in the advanced glazing research program.
Further, as with all of the FMVSSs, we drafted this final rule to
be performance-oriented, to provide manufacturers wide flexibility and
opportunity for design innovation in developing countermeasures that
could be used for ejection mitigation. We anticipate that manufacturers
will install ejection mitigation side curtain air bags in response to
this rulemaking, taking advantage of the side impact curtains already
in vehicles. Nonetheless, this final rule provides a role for advanced
glazing as a complement to ejection mitigation curtain systems.

[[Page 3223]]

NHTSA tested several vehicles' ejection mitigation side curtain air
bags both with and without advanced glazing to the 18 kg impactor
performance test adopted by this final rule. In the tests, the glazing
was pre-broken to simulate the likely condition of the glazing in a
rollover. Tests of vehicles with advanced glazing resulted in a 51 mm
average reduction in impactor displacement across target locations.\30\
That is, optimum (least) displacement of the headform resulted from use
of both an ejection mitigation window curtain and advanced glazing. To
encourage manufacturers to enhance ejection mitigation curtains with
advanced glazing, the final rule allows windows of advanced glazing to
be in-position for the 20 km/h-1.5 second test, although pre-broken to
reproduce the state of glazing in an actual rollover crash. This
approach encourages advanced glazing as a countermeasure to supplement
the vehicle's performance in meeting the 20 km/h-1.5 second test.\31\
---------------------------------------------------------------------------

\30\ See the technical analysis prepared by the agency in
support of the NPRM, placed in the docket for the NPRM (NHTSA-2009-
0183-007). ``Technical Analysis in Support of a Notice of Proposed
Rulemaking for Ejection Mitigation.'' Among other matters, the
report discusses the results of NHTSA's impactor testing of OEM and
prototype side window ejection mitigation systems.
\31\ Yet, after reviewing comments to the NPRM and other
information, we have decided not to permit movable glazing to
supplement the primary ejection mitigation system in the 16 km/h-6
second test. This is because field data indicate that even when
initially up, movable advanced glazing may be destroyed and rendered
ineffective as an effective countermeasure beyond the initial phase
of a rollover. In addition, 30 percent of occupants are ejected
through windows that are partially or fully open prior to the crash.
---------------------------------------------------------------------------

b. Full Window Opening Coverage Is Key

We considered the findings of several NHTSA research programs on
rollover crashworthiness protection in developing this final rule.
A cornerstone program started with the development of a dynamic
rollover fixture (DRF) that could be used to produce full-dummy
ejection kinematics in an open window condition, where the peak roll
rate ranged between 330 to 360 degrees/second. The DRF was used to
assess the potential effectiveness of ejection mitigation
countermeasures in a rollover.\32\ These countermeasures included
several designs of inflatable curtain air bags, advanced glazing, and
combinations of curtains and advanced glazing. The results of the
assessment showed that not all ejection mitigation air bag curtains
work the same way. We found that full window opening coverage was key
to the effectiveness of the curtain in preventing ejection.
---------------------------------------------------------------------------

\32\ NHTSA developed the DRF to produce full-dummy ejection
kinematics in a less costly manner than full-scale testing. The DRF
models a lateral rollover crash of approximately one vehicle
revolution. The DRF rotates approximately one revolution and comes
to rest through the application of a pneumatic braking system on one
end of the pivot axle. It does not simulate lateral vehicle
accelerations often encountered in a rollover crash prior to
initiation of the rollover event. The DRF has a test buck fabricated
from a Chevrolet CK pickup cab. The cab is longitudinally divided
down the center from the firewall to the B-pillar. The left (driver)
side is rigidly attached to the test platform. The Chevrolet CK was
chosen so that the advanced glazing systems developed in the
previous ejection mitigation research could be evaluated in this
program. A seat back and cushion were made from Teflon material, to
minimize the shear forces on the dummy buttocks for more desired
loading on the window area by the dummy's head and upper torso.
---------------------------------------------------------------------------

1. Tests with 50th Percentile Adult Male and 5th Percentile Adult
Female Test Dummies
In the first research program, experimental roof rail-mounted
inflatable devices developed by Simula Automotive Safety Devices
(Simula) and by TRW were evaluated on the DRF, along with an advanced
side glazing system.\33\ In the tests, unrestrained 50th percentile
male and 5th percentile female Hybrid III dummies, instrumented with 6
axis upper neck load cells and tri-axial accelerometers in the head,
were separately placed in the buck.\34\ The DRF rotation resulted in a
centripetal acceleration of the dummy that caused the dummy to move
outwards towards the side door/window. In baseline tests of the
unrestrained dummies in the DRF with an open side window and no
countermeasure, the dummies were fully ejected. The ability of the
countermeasure to restrain the dummies could then be assessed and
compared to that baseline test.
---------------------------------------------------------------------------

\33\ ``Status of NHTSA's Ejection Mitigation Research Program,''
Willke et al., 18th International Technical Conference on the
Enhanced Safety of Vehicles, paper number 342, June 2003.
\34\ Two dummy positions were used. The first was behind the
steering wheel. The second position was more inward, toward the
pivot axle, which generated higher contact velocities. Film analysis
was used to measure the dummy's relative head and shoulder contact
velocity with the side window plane from these two seating
positions. (For the final rule, we digitized the films and
reanalyzed the impact speeds using data from state-of-the-art
software. The resulting impacts speeds were lower than those
reported in the NPRM. The analysis will be discussed later in this
document.) From the first position behind the steering wheel, the
shoulder impact speeds were 7.0 km/h (4.3 mph) for the 5th
percentile female dummy and 9.0 km/h (5.6 mph) for the 50th male.
From the second (inboard) position, the velocities were 15.5 km/h
(9.6 mph) for the 5th female dummy and 15.8 km/h (9.8 mph) for the
50th male.
---------------------------------------------------------------------------

In the tests of the experimental inflatable devices, the air bags
were pre-deployed and their inflation pressure was maintained
throughout the test by the use of an air reservoir tank mounted on the
platform.\35\ In the tests, the dummy's upper body loaded the
inflatable device, which limited the dummy's vertical movement toward
the roof and caused the pelvis to load the side door throughout the
roll, rather than to ride up the door. The inflatable devices contained
the torso, head, and neck of the dummy, so complete ejection did not
occur. However, both devices did allow partial ejection of the dummy's
shoulder and arm below the bags, between the inflatable devices and the
vehicle door.
---------------------------------------------------------------------------

\35\ Since these were experimental systems, they were not
deployed through pyrotechnic or in-vehicle compressed gas, as might
be the case with production designs. The air pressure supplied by
the laboratory reservoir kept the systems fully inflated over the
test period.
---------------------------------------------------------------------------

In the test of the advanced side glazing (laminated with door/
window frame modifications around the entire periphery to provide edge
capture), the glazing contained the dummies entirely inside the test
buck. The glazing was not pre-broken before the testing. There was some
flexing of the window frame when the dummies loaded the glazing, and
the 50th percentile male dummy's shoulder shattered the glass when the
dummy was located behind the steering wheel.
In the test of the combined systems, the dummies remained entirely
inside the buck. Although the dummy's shoulder and arm escaped under
the inflatable devices, the advanced glazing prevented the partial
ejection seen in tests of the inflatable devices alone.
In these tests, the ejection mitigation systems did not show a high
potential for producing head and neck injury. However, head and neck
loading were higher than the open window condition. The highest load
with respect to the Injury Assessment Reference Values (IARVs) was 82
percent for the neck compression for the 5th percentile female tested
with the Simula/laminate combination. The highest injury response for
the 50th percentile male dummy was 59 percent for the neck compression
with the TRW system alone. All HIC36\36\ responses were
extremely low and ranged from 8 to 90, with the maximum occurring in an
open window test. Lateral shear and bending moment of the neck were
also measured, although there are no established IARVs. The maximum
lateral neck shear loads were 950 N (50th percentile male tested with
TRW

[[Page 3224]]

system) and 1020 N (5th percentile female tested with laminate only).
---------------------------------------------------------------------------

\36\ HIC36 is the Head Injury Criterion computed over
a 36 msec duration. HIC36 = 1,000 represents an onset of
concussion and brain injury.
---------------------------------------------------------------------------

2. Tests With 6-Year-Old Child Test Dummy Showed a Risk of Ejection
Through Openings Not Fully Covered
The second research program involved a series of tests on the DRF
using an unrestrained Hybrid III 6-year-old dummy. In previous tests
with the 50th percentile adult male and 5th percentile adult female
dummies, a gap formed between the inflatable devices and the window
sill (bottom of the window opening), which allowed partial ejection of
those adult dummies. The second program investigated whether the gap
allowed ejection of the 6-year-old child dummy.\37\
---------------------------------------------------------------------------

\37\ ``NHTSA's Crashworthiness Rollover Research Program,''
Summers, S., et al., 19th International Technical Conference on the
Enhanced Safety of Vehicles, paper number 05-0279, 2005.
---------------------------------------------------------------------------

In baseline testing with an open side window without activation of
an ejection mitigation countermeasure, the child dummy was fully
ejected. In tests of the two inflatable systems tested in the first
program (at the time of the second research program, the inflatable
device formerly developed by Simula was then developed by Zodiac
Automotive US (Zodiac)), the inflatable devices prevented full ejection
of the 6-year-old child dummy in upright-seated positions (no booster
seat was used). However, dummy loading on the systems produced gaps
that did allow an arm and/or hand to pass through in some tests.
Moreover, in a series of tests with the dummy lying in a prone position
(the dummy was placed on its back at the height of the bottom of the
window opening), representing a near worst-case ejection condition, the
dummy was completely ejected at positions near the bottom of the
inflatable devices (above the sill) with the TRW curtain, while the
Zodiac system contained the dummy inside the test buck in all testing.
Adding pre-broken advanced glazing with the TRW system managed to
contain the dummy inside the test buck in all tests.\38\
---------------------------------------------------------------------------

\38\ Id.
---------------------------------------------------------------------------

3. Differences in Design Between the Two Inflatable Systems
The two prototype inflatable devices tested had fundamentally
different designs. The Zodiac/Simula prototype system used an
inflatable tubular structure (ITS) \39\ tethered near the base of the A
and B-pillars that deployed a woven material over the window opening.
(The Zodiac system differed from the originally-tested Simula design in
that it had more window coverage. This was achieved by placing the ITS
tether locations lower on the pillars and adding additional woven
material.) The TRW prototype was more akin to a typical air bag curtain
and was fixed to the A- and B-pillar at its end points and along the
roof rail, but not tethered. The ITS differed from conventional air
bags in that it was not vented.
---------------------------------------------------------------------------

\39\ ITS systems were originally introduced by BMW as a side
impact countermeasure.
---------------------------------------------------------------------------

We believe that the better performance of the Zodiac prototype
system compared to that of TRW, in the DRF testing described above and
in impactor test results provided later in this preamble, was due to
the greater window coverage by the Zodiac prototype along the entire
sill and A-pillar.
4. Insights
The DRF research provided the following insights into ejection
mitigation curtains:
Inflatable devices prevented ejection of test dummies in
simulated rollover tests, but design differences accounted for
differences in performance;
Gaps in the inflatable device's coverage of the window
opening at the sill and A-pillar allowed partial ejection of adult
dummies and full ejection of a 6-year-old child dummy;
Adding pre-broken advanced glazing to an air bag system
enhanced the ability of the system to contain the dummy; and,
To optimize ejection mitigation potential, a performance
test should ensure that the countermeasure has full coverage of the
window opening.

c. Comparable Performance in Simulated Rollovers and Component-Level
Impact Tests

Because full-vehicle rollover crash tests can have an undesired
amount of variability in vehicle and occupant kinematics, in the
advanced glazing program NHTSA developed a component-level impact test
for assessing excursion and the risk of ejection. We use the component-
level test in this final rule for ejection mitigation.
The test involves use of a guided linear impactor designed to
replicate the loading of a 50th percentile male occupant's head and
shoulder during ejection situations. The impactor \40\ is described
later in this preamble. There are many possible ways of delivering the
impactor to the target location on the ejection mitigation
countermeasure. The ejection mitigation test device \41\ used by the
agency in the advanced glazing program and for the research used to
develop the NPRM (``old impactor'') has a propulsion mechanism \42\
with a pneumatic piston that pushes the shaft component of the
impactor. The old impactor shaft slides along a plastic (polyethylene)
bearing. The impactor has an 18 kg mass.
---------------------------------------------------------------------------

\40\ The ``ejection impactor'' is the moving mass that strikes
the ejection mitigation countermeasure. It consists of an ejection
headform attached to a shaft.
\41\ The ejection mitigation test device consists of an ejection
impactor and ejection propulsion mechanism.
\42\ The ``ejection propulsion mechanism'' is the component that
propels the ejection impactor and constrains it to move along its
axis or shaft.
---------------------------------------------------------------------------

The component-level test identified four impact locations to
evaluate a countermeasure's window coverage and retention capability.
Two of the positions were located at the extreme corners of the window/
frame and were located such that a 25 mm gap existed between the
outermost perimeter of the headform and window frame. A third position
was near the transition between the upper window frame edge and A-
pillar edge. The fourth position was at the longitudinal midpoint
between the third position and the position at the upper extreme corner
of the window/door frame, such that the lowest edge of the headform was
25 mm above the surface of the door at the bottom of the window
opening.
At each impact location, different impact speeds and different time
delays between air bag deployment and impact were used. To simulate
ejection early in a rollover event and in a side impact, the air bags
were impacted 1.5 seconds after air bag deployment, at 20 and 24 km/h.
To simulate ejection late in a rollover event, the air bags were
impacted after a delay of 6 seconds at an impact speed of 16 km/h.
Findings
The two inflatable systems tested in the above-described research
programs (the inflatable devices developed by Zodiac and by TRW) were
installed on a Chevrolet CK pickup cab and subjected to the component-
level impact test. The air bag systems were evaluated for allowable
excursion (impactor displacement) beyond the side window plane. The
tests also assessed the degree to which the component-level test was
able to replicate the findings of the DRF tests.
The component-level tests mimicked the DRF tests by revealing the
same deficiencies in the side curtain air bags that were highlighted in
the dynamic test. On the other hand, the Zodiac

[[Page 3225]]

system \43\ did not allow the impactor to go beyond the plane of the
window in the 16 km/h and 20 km/h tests. The air bag allowed only 12
and 19 mm of excursion beyond the window plane in the 24 km/h tests.
---------------------------------------------------------------------------

\43\ Testing was restricted to the extreme corners of the window
due to limited availability of this system.
---------------------------------------------------------------------------

In the 24 km/h tests of the TRW system, the curtain was not able to
stop the impactor before the limits of travel were reached (about 180
mm beyond the plane for the vehicle window for that test setup) at the
position at the extreme forward corner of the window sill. This is the
position at which the TRW prototype system allowed excessive excursion
of the test dummies in the DRF dynamic tests. In the DRF tests, the 6-
year-old dummy was completely ejected through that window area even
when the prone dummy was aimed at the position at the other extreme
corner of the window. In other tests, the TRW prototype system was able
to stop the impactor before the impactor reached its physical stops.

d. Advantages of a Component Test Over a Full Vehicle Dynamic Test

NHTSA determined that the component test not only distinguishes
between acceptable and unacceptable performance in side curtain air
bags, but has advantages over a full vehicle dynamic test. The
acceptable (or poor) performance in the laboratory test correlated to
the acceptable (or poor) performance in the dynamic test. The component
test was able to reveal deficiencies in window coverage of ejection
mitigation curtains that resulted in partial or full ejections in
dynamic conditions. Incorporating the component test into an ejection
mitigation standard ensures that ejection mitigation countermeasures
provide sufficient coverage of the window opening for as long in the
crash event as the risk of ejection exists, which is a key component
contributing to the efficacy of the system.
As noted earlier, rollover crash tests can have an undesirable
amount of variability in vehicle and occupant kinematics. In contrast,
the repeatability of the component test has been shown to be good.\44\
Moreover, there are many types of rollover crashes, and within each
crash type the vehicle speed and other parameters can vary widely. A
curb trip can be a very fast event with a relatively high lateral
acceleration. Soil and gravel trips have lower lateral accelerations
than a curb trip and lower initial roll rates. Fall-over rollovers are
the longest duration events, and it can be difficult to distinguish
between rollover and non-rollover events. Viano and Parenteau \45\
correlated eight different tests to six rollover definitions from NASS-
CDS.\46\ Their analysis indicated that the types of rollovers occurring
in the real-world varied significantly. Soil trip rollovers accounted
for more than 47 percent of the rollovers in the field, while less than
1 percent of real-world rollovers were represented by the FMVSS No. 208
Dolly test (``208 Dolly test'').
---------------------------------------------------------------------------

\44\ ``NHTSA's Crashworthiness Rollover Research Program,''
supra.
\45\ Viano D, Parenteau C. Rollover Crash Sensing and Safety
Overview. SAE 2004-01-0342.
\46\ ``Technical Analysis in Support of a Notice of Proposed
Rulemaking for Ejection Mitigation,'' supra.
---------------------------------------------------------------------------

Occupant kinematics will also vary with these crash types,
resulting in different probabilities of occupant contact on certain
areas of the side window opening with differing impact energies. A
single full vehicle rollover test could narrowly focus on only certain
types of rollover crashes occurring in the field.\47\ Assuming it is at
all possible to comprehensively assess ejection mitigation
countermeasures through full vehicle dynamic testing, multiple crash
scenarios would have to be involved.
---------------------------------------------------------------------------

\47\ The agency has in the past performed dolly type dynamic
testing. The agency has not performed enough repeat tests of the
same vehicles to draw any conclusions about the repeatability of
these tests to determine occupant containment. However, regardless
of the level of repeatability of dummy kinematics, it still only
represents a part of the kinematics that would occur in the field.
---------------------------------------------------------------------------

Such a suite of tests imposes test burdens and costs that could be
avoided by a component test, such as that adopted today. We also note
that a comprehensive suite of full-vehicle dynamic tests would involve
many more years of research, which would delay this rulemaking action
and the implementation of life-saving curtain air bag technologies.
Such a delay is unwarranted and undesirable since the component test
will be an effective means of determining the acceptability of ejection
countermeasures.

VIII. Availability of Side Curtain Air Bags

The availability of vehicles that offer inflatable side curtains
that deploy in a rollover has increased since they first became
available in 2002. In the middle of the 2002 model year (MY), Ford
introduced the first generation of side curtain air bags that were
designed to deploy in the event of a rollover crash. The rollover air
bag curtain system, marketed as a ``Safety Canopy,'' was introduced as
an option on the Ford Explorer and Mercury Mountaineer.\48\ For the
2007 MY, rollover sensors were available on approximately 95 models,
with 75 of these models being sport utility vehicles. The system was
standard equipment on 62 vehicles (65 percent) and optional on 33
vehicles (35 percent).
---------------------------------------------------------------------------

\48\ http://media.ford.com/article_display.cfm?article_id=6447
(Last accessed October 8, 2010.)
---------------------------------------------------------------------------

Annually, as part of NHTSA's New Car Assessment Program (NCAP), the
agency sends a questionnaire to manufacturers requesting information
about the availability of certain safety systems on their vehicles.\49\
Since 2008, NHTSA has asked manufacturers for voluntary responses
regarding whether their available side impact curtains will deploy in a
rollover crash. The voluntary responses were in the affirmative for 39
percent of MY 2008 make models and for 43 percent of MY 2010 make
models.
---------------------------------------------------------------------------

\49\ The total number of make/models represented in the survey
is about 500. Slight model variations are represented as different
models and corporate twins are not combined.
---------------------------------------------------------------------------

IX. Existing Curtains

Aside from the presence of a rollover sensor, there are two
important design differences between air bag curtains designed for
rollover ejection mitigation and air bag curtains designed only for
side impact protection. The first difference is longer inflation
duration. Rollover crashes with multiple full vehicle rotations can
last many seconds. Ford has stated that its Safety Canopy stays
inflated for 6 seconds,\50\ while GM stated that its side curtain air
bags designed for rollover protection maintain 80 percent inflation
pressure for 5 seconds.\51\ Honda stated that the side curtains on the
2005 and later Honda Odyssey stay fully inflated for 3 seconds.\52\ In
contrast, side impact air bag curtains designed for occupant protection
in side crashes, generally stay inflated for less than 0.1 seconds.
---------------------------------------------------------------------------

\50\ Ibid.
\51\ ``Who Benefits From Side and Head Airbags?'' (http://www.edmunds.com/ownership/safety/articles/105563/article.html).
(Last accessed October 5, 2010.)
\52\ http://www.autodeadline.com/detail?source=Honda&mid=HON2004083172678&mime=ASC. (Last accessed
October 5, 2010.)
---------------------------------------------------------------------------

The second important air bag curtain design difference between
rollover and side impact protection is the size or coverage of the air
bag curtain. One of the most obvious trends in newer vehicles is the
increasing area of coverage for rollover curtains. Referring to earlier
generations of curtains, Ford has stated that its rollover protection
air bags covered between 66 and 80 percent

[[Page 3226]]

of the first two rows of windows, and that it was expanding the designs
so they cover all three rows in all models.\53\ GM stated that its
curtains designed for rollover protection are larger than non-rollover
curtains.\54\
---------------------------------------------------------------------------

\53\ Ibid.
\54\ Who Benefits From Side and Head Airbags?'' (http://www.edmunds.com/ownership/safety/articles/105563/article.html),
supra.
---------------------------------------------------------------------------

a. Existing Curtains Tested to Proposed Requirements

The agency presented data in the NPRM from testing of eight MY 2003
through MY 2006 vehicles. Since the date of publication of the NPRM,
the agency tested 16 vehicle models to the proposed ejection mitigation
requirements. Data from these tests supplement the data from tests of
eight MY 2003 through MY 2006 vehicles discussed in the NPRM and are
discussed in this section. Most of the testing of the 16 vehicle models
was with the old impactor used in the NPRM tests. Tests from three
vehicles were performed with a new test device (``new impactor''). To
date we have performed nearly 700 impacts.
Figure 1 shows the target location key for the test results. In the
data, the C1-C4 targets follow the same positioning as the B1-B4
targets. In a few instances, the A2 and A3 targets were eliminated
because they were too close and a target (A5) was placed back in the
window because the centers of remaining targets A1 and A4 were more
than 360 mm apart.
[GRAPHIC] [TIFF OMITTED] TR19JA11.000

General Results
The results of the agency testing are given in Tables 10 through
18, below. The results are given in columns, by target location and are
in units of millimeters. (The technical report accompanying this
document has the data color-coded. Values exceeding the proposed 100 mm
limit of impactor displacement are in red or the darkest shading.
Results from 80 to 100 mm of displacement are purple or medium shading.
Results which are less than 80 mm are in green or the lightest
shading.) Some cells contain the average from several tests under the
same/similar conditions; these results are bolded. In some tests there
was so little resistance to the impactor that it continued past the
countermeasure to the point where the internal limit of the impact
prevented any additional displacement. In these cases, the numerical
value of displacement has no meaning so the cell is denoted as ``To
Stops.''
On occasion, target locations were not tested at 24 km/h because
the 20 km/h results indicated displacements in excess of 100 mm at that
location. These cells are denoted by ``(20 km/h)'' and we assume the 24
km/h impact would also have exceeded 100 mm. Similarly, some target
locations were not tested at 20 km/h, but the cells contain ``(24 km/
h)'' indicating a value below 80 mm of displacement in the 24 km/h test
and we assume the 20 km/h impact would have resulted in a displacement
less than 80 mm.
As detailed later, some vehicles were tested with pre-broken
advanced laminated (designated as ``w/lam.'' next to the vehicle name).
Various breaking methods were used. For simplicity in presenting the
data, we have averaged the results for various breaking methods, except
for the method of breaking the laminated in four places (designated as
``4 hole'' next to the vehicle name). Also, a few tests were performed
with the headliner in place (designated as ``w/liner'' next to the
vehicle name). ``N/O'' refers to whether the test was conducted with
the old ``O'' or new ``N'' impactor.
Across all vehicles, as was the case with our previous analysis of
test data in the NPRM, target A1 remains the most challenging impact
location and A4 the least challenging for the 1st row. This is
consistent for all three impactor speeds and time delays. For the 2nd
row, B1 and B2 are the most challenging. The available data do not
present a clear trend for the 3rd row.
The two best performing vehicles were the MY 2007 Mazda CX9 and the
MY 2008 Toyota Highlander. We will discuss the performance of these
vehicles in more detail in several of the sections below.

Table 10--Front Row Window, 24 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. A1 Pos. A2 Pos. A3 Pos. A4
----------------------------------------------------------------------------------------------------------------
03 Navigator.............................. O No Data (20 km/h) (20 km/h) -21
03 Navigator w/lam........................ O No Data 35 No Data No Data
04 Volvo XC90............................. O (20 km/h) 193 130 18
04 Volvo w/lam............................ O (20 km/h) 44 118 15
05 Chevy Trailblazer...................... O 138 168 159 No Data
05 Chevy Trailblazer w/lam................ O No Data No Data (20 km/h) No Data
05 Chevy Trail. w/lam. (4 hole)........... O No Data 89 No data No Data

[[Page 3227]]

05 Honda Odyssey.......................... O No data 107 119 No data
05 Infinity FX35.......................... O 128 101 99 55
05 Nissan Pathfinder...................... O (20 km/h) 167 (20 km/h) 79
05 Toyota Highlander...................... O (20 km/h) 137 142 116
06 Dodge Durango.......................... O 174 156 (20 km/h) 54
06 Dodge Durango w/lam.................... O No Data 101 No data No Data
06 Dodge Dur. w/lam. (4 hole)............. O (20 km/h) 95 (20 km/h) No Data
06 Mercury Monterey....................... O To Stops 208 No data 32
06 Toyota Land Cruiser.................... O 229 No data (20 km/h) 62
06 Volvo C70.............................. O (20 km/h) No Target No Target No Target
07 Chevy Silverado........................ O 177 (20 km/h) 183 -1
07 Chevy Tahoe............................ O To Stops 168 125 -25
07 Chevy Tahoe w/lam...................... O 113 100 124 No data
07 Chevy Tahoe w/lam. (4 hole)............ O No data 99 109 No data
-----------------------------------------
07 Ford 500............................... O (20 km/h) 160 38
-----------------------------------------
07 Ford Edge.............................. O 146 17 86 -9
07 Ford Edge.............................. N 175 No data 155 No data
07 Ford Expedition........................ O (20 km/h) (20 km/h) (20 km/h) 21
07 Jeep Commander......................... O (20 km/h) (20 km/h) (20 km/h) -62
07 Jeep Commander w/lam................... O No data No data 148 No data
07 Mazda CX9.............................. O 96 9 87 2
07 Mazda CX9.............................. N 112 No data 90 No data
07 Saturn Vue............................. O (20 km/h) (20 km/h) (20 km/h) 65
08 Dodge Caravan.......................... O 136 84 (20 km/h) -61
08 Ford Taurus X.......................... O 146 73 99 -38
-----------------------------------------
08 Subaru Tribeca......................... O (20 km/h) 146 74
-----------------------------------------
08 Toyota Highlander...................... O 64 41 54 12
08 Toyota Highlander...................... N 102 No data 77 No data
08 Toyota High. w/liner................... N 90 No data 70 No data
09 Chevy Equinox.......................... O (20 km/h) 101 (20 km/h) 30
Average................................... ............ 135 104 114 21
Standard Deviation........................ ............ 42.1 55.8 33.7 45.9
----------------------------------------------------------------------------------------------------------------

Table 11--Front Row Window, 20 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. A1 Pos. A2 Pos. A3 Pos. A4
----------------------------------------------------------------------------------------------------------------
03 Navigator.............................. O No Data 191 To Stops -37
03 Navigator w/lam........................ O No Data 6 No Data No Data
04 Volvo XC90............................. O 163 96 119 -3
04 Volvo w/lam............................ O 127 27 97 (24 km/h)
05 Chevy Trailblazer...................... O 112 121 127 No Data
05 Chevy Trailblazer w/lam................ O 86 80 109 No Data
05 Chevy Trail. w/lam. (4 hole)........... O No Data 62 98 No Data
05 Honda Odyssey.......................... O No data 96 57 -45
05 Infinity FX35.......................... O 106 60 73 30
05 Nissan Pathfinder...................... O 192 138 248 60
05 Toyota Highlander...................... O 168 137 115 76
06 Dodge Durango.......................... O 160 140 180 18
06 Dodge Dur. w/lam. (4 hole)............. O 106 71 150 No Data
06 Mercury Monterey....................... O 185 199 No data -10
06 Toyota Land Cruiser.................... O 174 No data 256 31
06 Volvo C70.............................. O 200 No Target No Target No Target
07 Chevy Silverado........................ O 142 187 130 (24 km/h)
07 Chevy Tahoe............................ O 104 110 87 (24 km/h)
07 Chevy Tahoe w/lam...................... O 102 No data No data No data
-----------------------------------------
07 Ford 500............................... O 192 113 (24 km/h)
-----------------------------------------
07 Ford Edge.............................. O 129 (24 km/h) No data (24 km/h)
07 Ford Edge.............................. N 148 No data 67 No data
07 Ford Expedition........................ O 151 To Stops 137 (24 km/h)
07 Jeep Commander......................... O To Stops 175 155 (24 km/h)
07 Jeep Commander w/lam................... O No data No data 73 No data
07 Mazda CX9.............................. N 76 No data 67 No data
07 Saturn Vue............................. O To Stops 130 191 28
08 Dodge Caravan.......................... O 112 No data 162 (24 km/h)

[[Page 3228]]

08 Ford Taurus X.......................... O 110 No data No data (24 km/h)
-----------------------------------------
08 Subaru Tribeca......................... O 180 106 (24 km/h)
-----------------------------------------
09 Chevy Equinox.......................... O 149 No data 200 (24 km/h)
Average................................... ............ 140 112 132 15
Standard Deviation........................ ............ 36.5 55.7 56.7 39.0
----------------------------------------------------------------------------------------------------------------

Table 12--Front Row Window, 16 km/h Impact, 6 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. A1 Pos. A2 Pos. A3 Pos. A4
----------------------------------------------------------------------------------------------------------------
03 Navigator.............................. O To Stops 74 To Stops -30
03 Navigator w/lam........................ O 157 -36 137 No Data
04 Volvo XC90............................. O 161 73 78 -22
04 Volvo w/lam............................ O 96 26 59 No Data
05 Chevy Trailblazer...................... O 121 192 124 No Data
05 Chevy Trailblazer w/lam................ O No Data 102 No Data No Data
05 Chevy Trail. w/lam. (4 hole)........... O No Data 92 No Data No Data
05 Honda Odyssey.......................... O No Data 69 77 -54
05 Infinity FX35.......................... O 88 22 40 9
05 Nissan Pathfinder...................... O 117 104 195 43
05 Toyota Highlander...................... O 205 210 152 69
06 Dodge Durango.......................... O 138 135 167 13
06 Dodge Durango w/lam.................... O No Data No Data 142 No Data
06 Dodge Dur. w/lam. (4 hole)............. O 97 58 145 No Data
06 Mercury Monterey....................... O 222 183 No Data 35
06 Toyota Land Cruiser.................... O 146 207 229 16
06 Volvo C70.............................. O 135 No Target No Target No Target
07 Chevy Silverado........................ O 145 244 115 -7
07 Chevy Tahoe............................ O 42 6 10 -136
-----------------------------------------
07 Ford 500............................... O 151 58 -16
-----------------------------------------
07 Ford 500 w/lam......................... O 96 No Data No Data No Data
07 Ford Edge.............................. O 103 -42 7 -56
07 Ford Edge.............................. N 123 No Data 33 No Data
07 Ford Expedition........................ O 141 205 109 3
07 Jeep Commander......................... O 255 144 136 -89
07 Jeep Commander w/lam................... O No Data 56 62 No Data
07 Jeep Commander w/lam. (4 hole)......... O No Data 50 60 No Data
07 Mazda CX9.............................. O 54 -38 44 -53
07 Mazda CX9.............................. N 67 No Data 31 No Data
07 Saturn Vue............................. O 184 180 186 72
08 Dodge Caravan.......................... O 85 -39 121 -141
08 Ford Taurus X.......................... O 104 -13 39 -88
-----------------------------------------
08 Subaru Tribeca......................... O 122 77 -1
-----------------------------------------
08 Toyota Highlander...................... O 36 0 54 -62
08 Toyota Highlander...................... N 119 No Data 52 No Data
09 Chevy Equinox.......................... O 125 25 178 -46
Average................................... ............ 125 82 99 -25
Standard Deviation........................ ............ 50.1 87.2 61.1 58.1
----------------------------------------------------------------------------------------------------------------

Table 13--Second Row Window, 24 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. B1 Pos. B2 Pos. B3 Pos. B4
----------------------------------------------------------------------------------------------------------------
03 Ford Navigator......................... O To Stops No data No data 40
04 Volvo XC90............................. O (20 km/h) No data No data 69
04 Volvo XC90 w/lam....................... O 92 No data No data 62
05 Chevy Trailblazer...................... O 122 No data No data 35
05 Honda Odyssey.......................... O 152 193 71 80
05 Infinity FX35.......................... O 148 No data No data 47
05 Nissan Pathfinder...................... O 167 No data No data 133
05 Toyota Highlander...................... O 152 No data No data 154
06 Dodge Durango.......................... O 86 82 76 91
06 Mercury Monterey....................... O 171 193 72 78
06 Toyota Land Cruiser.................... O 159 157 75 No Target
07 Chevy Silverado........................ O 153 (20 km/h) 78 117

[[Page 3229]]

07 Chevy Tahoe............................ O (20 km/h) 161 24 74
07 Chevy Tahoe w/lam...................... O No data 48 No data No data
07 Ford 500............................... O 184 50 102 157
07 Ford 500 w/lam......................... O 91 No data No data 111
07 Ford 500 w/lam. (4 hole)............... O No data No data No data 99
07 Ford Edge.............................. O 39 21 -22 27
07 Ford Edge.............................. N 51 33 No data 26
07 Ford Expedition........................ O 164 55 66 75
07 Jeep Commander......................... O 140 (20 km/h) 64 No data
07 Mazda CX9.............................. O 36 2 51 9
07 Mazda CX9.............................. N 22 No data 44 No data
07 Saturn Vue............................. O No Target 144 66 No Target
08 Dodge Caravan.......................... O 59 27 -16 -7
08 Ford Taurus X.......................... O 45 34 22 31
08 Subaru Tribeca......................... O 133 85 80 111
08 Toyota Highlander...................... O 106 110 55 109
08 Toyota Highlander...................... N 125 144 No data 133
08 Toyota High. w/liner................... N 133 138 No data 77
09 Chevy Equinox.......................... O 72 22 39 45
Average................................... ............ 112 89 53 76
Standard Deviation........................ ............ 49.2 63.0 32.7 44.0
----------------------------------------------------------------------------------------------------------------

Table 14--Second Row Window, 20 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. B1 Pos. B2 Pos. B3 Pos. B4
----------------------------------------------------------------------------------------------------------------
03 Ford Navigator......................... O To Stops No data No data -14
04 Volvo XC90............................. O 183 No data No data (24 km/h)
04 Volvo XC90 w/lam....................... O 94 No data No data (24 km/h)
05 Chevy Trailblazer...................... O 68 No data No data 8
05 Honda Odyssey.......................... O 134 84 42 34
05 Infinity FX35.......................... O 90 No data No data 21
05 Nissan Pathfinder...................... O 143 No data No data 111
05 Toyota Highlander...................... O 110 No data No data 106
06 Mercury Monterey....................... O 155 52 42 51
06 Toyota Land Cruiser.................... O 127 128 53 No Target
07 Chevy Silverado........................ O 114 232 (24 km/h) 101
07 Chevy Tahoe............................ O 249 No data (24 km/h) (24 km/h)
07 Ford 500............................... O 152 No data 89 128
07 Ford Expedition........................ O 146 23 (24 km/h) (24 km/h)
07 Jeep Commander......................... O 122 107 (24 km/h) No data
07 Saturn Vue............................. O No Target 111 40 No Target
08 Subaru Tribeca......................... O 105 No data (24 km/h) No data
08 Toyota Highlander...................... O No data 67 (24 km/h) 88
08 Toyota Highlander...................... N 92 89 No data 110
Average................................... ............ 130 99 53 64
Standard Deviation........................ ............ 43.4 59.3 20.7 49.9
----------------------------------------------------------------------------------------------------------------

Table 15--Second Row Window, 16 km/h Impact, 6 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. B1 Pos. B2 Pos. B3 Pos. B4
----------------------------------------------------------------------------------------------------------------
03 Ford Navigator......................... O 126 No data No data -27
04 Volvo XC90............................. O 189 No data No data 29
04 Volvo XC90 w/lam....................... O 63 No data No data 9
05 Chevy Trailblazer...................... O 127 No data No data 47
05 Honda Odyssey.......................... O 121 28 12 55
05 Infinity FX35.......................... O 64 No data No data 20
05 Nissan Pathfinder...................... O 111 No data No data 78
05 Toyota Highlander...................... O 143 No data No data 110
06 Dodge Durango.......................... O 36 18 3 71
06 Mercury Monterey....................... O 223 142 54 54
06 Toyota Land Cruiser.................... O 107 113 49 No Target
07 Chevy Silverado........................ O 124 194 53 63
07 Chevy Tahoe............................ O 120 -83 -21 15
07 Chevy Tahoe w/lam...................... O 66 No data No data No data
07 Chevy Tahoe w/lam. (4 hole)............ O 58 No data No data No data
07 Ford 500............................... O 133 -3 56 94
07 Ford 500 w/lam......................... O 64 No data No data No data
07 Ford Edge.............................. O -16 -40 -76 -25

[[Page 3230]]

07 Ford Expedition........................ O 89 159 22 34
07 Jeep Commander......................... O 107 99 27 57
07 Mazda CX9.............................. O -15 -58 5 -35
07 Saturn Vue............................. O No data 138 26 No data
08 Dodge Caravan.......................... O -58 -29 -55 -56
08 Ford Taurus X.......................... O -17 -19 -13 -40
08 Subaru Tribeca......................... O 76 19 28 20
08 Toyota Highlander...................... O 49 59 32 57
08 Toyota Highlander...................... N 87 105 No data 93
09 Chevy Equinox.......................... O 15 -51 1 -14
Average................................... ............ 81 44 12 31
Standard Deviation........................ ............ 63.9 84.5 37.2 46.8
----------------------------------------------------------------------------------------------------------------

Table 16--Third Row Window, 24 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. C1 Pos. C2 Pos. C3 Pos. C4
----------------------------------------------------------------------------------------------------------------
05 Honda Odyssey.......................... O No data (20 km/h) No data 175
06 Mercury Monterey....................... O 188 (20 km/h) 119 No data
06 Toyota Land Cruiser.................... O NC NC 180 NC
07 Chevrolet Tahoe........................ O 91 No Target 194 No Target
07 Chevrolet Tahoe w/lam.................. O No Data 106 141 No Data
07 Ford Expedition........................ O (20 km/h) No data 81 186
07 Jeep Commander......................... O 229 155 120 102
08 Dodge Caravan.......................... O -42 112 35 -41
08 Ford Taurus X.......................... O No Target To Stops 48 No Target
08 Toyota Highlander...................... O -42 42 92 No data
08 Toyota Highlander...................... N No data No data 110 No data
08 Toyota Highlander w/liner.............. N No data No data 42 No data
Average................................... ............ 85 104 106 106
Standard Deviation........................ ............ 126.1 46.6 53.1 104.5
----------------------------------------------------------------------------------------------------------------

Table 17--Third Row Window, 20 km/h Impact, 1.5 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O* Pos. C1 Pos. C2 Pos. C3 Pos. C4
----------------------------------------------------------------------------------------------------------------
05 Honda Odyssey.......................... O No data To Stops 58 122
06 Dodge Durango.......................... O No data To Stops 66 No data
06 Mercury Monterey....................... O 147 212 75 No data
06 Toyota Land Cruiser.................... O NC NC 128 NC
07 Chevrolet Tahoe........................ O 58 No Target No data No Target
07 Ford Expedition........................ O 241 No data No data 51
07 Jeep Commander......................... O No data 115 102 No data
08 Ford Taurus X.......................... O No Target 86 (24 km/h) No Target
08 Toyota Highlander...................... N No data No data 88 No data
Average................................... ............ 149 138 86 86
Standard Deviation........................ ............ 91.5 66.0 25.8 50.6
----------------------------------------------------------------------------------------------------------------

Table 18--Third Row Window, 16 km/h Impact, 6 Second Delay
----------------------------------------------------------------------------------------------------------------
Vehicle N/O * Pos. C1 Pos. C2 Pos. C3 Pos. C4
----------------------------------------------------------------------------------------------------------------
05 Honda Odyssey.......................... O To Stops To Stops 44 80.
06 Dodge Durango.......................... O No Data No Data 52 No Data.
06 Mercury Monterey....................... O 186 204 142 225.
06 Toyota Land Cruiser.................... O NC NC 98 NC.
07 Chevrolet Tahoe........................ O 30 No Target 64 No Target.
07 Chevrolet Tahoe w/lam.................. O No Data 57 66 No Data.
07 Ford Expedition........................ O 233 No Data 49 34.
07 Jeep Commander......................... O 170 104 92 56.
08 Dodge Caravan.......................... O -91 34 -42 -113.
08 Ford Taurus X.......................... O No Target 60 7 No Target.
08 Toyota Highlander...................... O No Data -23 37 No Data.
Average................................... ............ 106 73 55 56.
Standard Deviation........................ ............ 133.4 76.5 48.2 120.6.
----------------------------------------------------------------------------------------------------------------

[[Page 3231]]

Trends in Performance of Ejection Mitigation Systems by MY Using Old
Impactor
Based on the vehicles the agency tested, there appears to be a
trend toward improved performance as each model year passes. This is
demonstrated by increased coverage of the window opening in the more
recent MY vehicles tested and the ability of the countermeasure to
restrain displacement of the impactor. While it is difficult to
quantify this trend, the trend is shown graphically below by plots of
displacement values by model year for the 1st row (Figure 2) and 2nd
Row (Figure 3). These graphs are restricted to the 24 km/h-1.5 second
test using the old impactor and exclude any testing with advanced
glazing.

Note: Not shown in the figure are data from older vehicles which
often had no curtain coverage at a particular target. If there was
no curtain coverage, we did not test the target since the 100 mm
displacement limit would have been exceeded. Although these vehicles
are not shown on the graph, their improved curtain coverage in
recent MY vehicles is indicative of improved performance over time.

Since the graphs span multiple vehicles, there is scatter in the
data. Nonetheless, when a trend line is plotted through the data for
each impact location it shows decreasing displacement for newer models.
[GRAPHIC] [TIFF OMITTED] TR19JA11.001

[[Page 3232]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.002

One comparison to note for illustration purposes is the improved
performance of the MY 2008 Highlander in comparison to the MY 2005
Highlander. Table 19 shows the change in displacement values for the
two model years of the Highlander at each target location and across
impact speeds. The largest change in displacement value was for the 16
km/h tests at targets A1 and A2 (169 mm and 210 mm, respectively). On
an average basis, the MY 2008 Highlander had 103 mm less displacement
across all tested target locations, for a 76 percent overall reduction.
This is illustrative of the improved performance of later MY vehicles.
We believe that the MY 2008 Highlander had increased coverage of the
ejection mitigation curtain and increased size of the inflated chambers
which helped to restrain the impactor.

Table 19--Old Impactor, Absolute and Percentage Change in Displacement (mm) Between MY2005 and MY2008 Toyota
Highlander
----------------------------------------------------------------------------------------------------------------
Test vel. A1 A2 A3 A4 B1 B4
----------------------------------------------------------------------------------------------------------------
24...................................... .......... -96 -88 -104 -46 -45
16...................................... -169 -210 -98 -131 -94 -53
-----------------------------------------------------------------------
Average (mm)............................ -103
----------------------------------------------------------------------------------------------------------------
24...................................... .......... -70% -62% -90% -30% -29%
16...................................... -82% -100% -64% -190% -66% -48%
-----------------------------------------------------------------------
Average (%)............................. -76%
----------------------------------------------------------------------------------------------------------------

Comparing Results of Tests With Old and New Impactors
Several vehicles (the MY2008 CX9, Edge and Highlander) were tested
using both the old and new impactor.
Table 20 shows the difference in displacements measured at target
locations where both impactors were used.\55\ Not surprisingly, these
data generally indicate that the new impactor tends to result in
greater displacement (positive difference); we believe this is due to
lower dynamic friction. Yet, the old impactor displacement exceeded the
new impactor (negative difference) at several targets as well.
---------------------------------------------------------------------------

\55\ In some cases average values were used to calculate the
differences.
---------------------------------------------------------------------------

The CX9 was the only vehicle that was impacted multiple times at
the same targets by both the old and new

[[Page 3233]]

impactor. A student's t-test was performed to determine if the
difference in the results were significant.\56\ Table 21 shows the
displacement values and statistics for targets A1 and A3. The
difference in displacement was statistically significant (p<=0.05) for
the A1 target, but not the A3 target.
---------------------------------------------------------------------------

\56\ The one sided t-test was performed assuming equal variance
to determine if the new test device had produced larger displacement
values compared to the old device.

Table 20--Change in Displacement Between Old and New Impact Test Device
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vehicle Test vel. (km/h) A1 A3 B1 B2 B3 B4 C3
--------------------------------------------------------------------------------------------------------------------------------------------------------
08 Ford Edge............................. 24....................... 29.0 69.0 12.0 12.0 .......... -1.0 ..........
08 Mazda CX9............................. 24....................... 15.5 3.0 -14.0 0.0 -7.0 0.0 ..........
08 Toyota Highlander..................... 24....................... 38.5 23.0 19.0 34.0 .......... 24.0 18.0
08 Ford Edge............................. 20....................... 18.5 .......... .......... .......... .......... .......... ..........
08 Toyota Highlander..................... 20....................... .......... .......... .......... 22.0 .......... 22.0 ..........
08 Ford Edge............................. 16....................... 19.5 26.0 .......... .......... .......... .......... ..........
08 Mazda CX9............................. 16....................... 13.0 -13.0 .......... .......... .......... .......... ..........
08 Toyota Highlander..................... 16....................... 83.0 -2.0 38.0 46.0 .......... 36.0 ..........
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average.................. 31.0 17.7 13.8 28.5 -7.0 20.3 18.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average All 21.6
--------------------------------------------------------------------------------------------------------------------------------------------------------

Table 21--Impactor Comparison for Mazda CX9
----------------------------------------------------------------------------------------------------------------
A1 A3
Test Vel. (km/h) -----------------------------------------------------------------------
Old New Old New
----------------------------------------------------------------------------------------------------------------
24...................................... 94 110 84 90
98 113 89 89
Average................................. 96.0 111.5 86.5 89.5
Std..................................... 2.8 2.1 3.5 0.7
-----------------------------------------------------------------------
P-Value................................. 0.013
0.180
----------------------------------------------------------------------------------------------------------------

Despite the differences in test results, the test results from the
old impactor provided useful data to assess the relative performance of
ejection mitigation countermeasures. The results from the impactor are
useful when analyzing data obtained from the old impactor alone, to
compare vehicles to each other or to previous model year vehicles, or
compare data from impact points on a vehicle.
Research Testing With New Impactor
As part of our analysis of the data, we evaluated data from only
the new impactor to avoid confounding the comparison of data by
impactor differences. Table 22 shows the change in displacement between
the 24 km/h-1.5 second, 20 km/h-1.5 second and 16 km/h-6 second tests
at various target locations for the MY 2007 Edge, MY 2007 CX9 and MY
2008 Highlander. The 24 km/h-1.5 second test always had greater
displacement than the 20 km/h-1.5 second test. On average this
difference was 38.3 mm when averaged over all vehicles and target
locations. This is an expected result because the only difference is
the impact speed.

Table 22--New Impactor, Change in Displacement (mm) Between 24 km/h 1.5 Second, 20 km/h 1.5 Second and 16 km/h 6 Second Tests
--------------------------------------------------------------------------------------------------------------------------------------------------------
Test
Vehicle comparison A1 A3 B1 B2 B4 C3
--------------------------------------------------------------------------------------------------------------------------------------------------------
07 Ford Edge....................................................... 24-20 28 88 .......... .......... .......... ..........
07 Mazda CX9....................................................... 24-20 36 23 .......... .......... .......... ..........
08 Toyota Highlander............................................... 24-20 .......... .......... 33 55 23 22
07 Ford Edge....................................................... 24-16 53 122 .......... .......... .......... ..........
07 Mazda CX9....................................................... 24-16 45 59 .......... .......... .......... ..........
08 Toyota Highlander............................................... 24-16 -17 25 38 39 40 ..........
07 Ford Edge....................................................... 20-16 25 34 .......... .......... .......... ..........
07 Mazda CX9....................................................... 20-16 9 36 .......... .......... .......... ..........
08 Toyota Highlander............................................... 20-16 .......... .......... 5 -16 17 ..........
------------------------------------------------------------------------------------
Average All--24-20.............................................................. 38.3
Average All--24-16.............................................................. 44.7
Average All--20-16.............................................................. 15.7
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 3234]]

There were only two vehicles/target locations that had more than
one impact at multiple test speeds. Although this is extremely limited
data, they allow a t-test to be performed.\57\ The results are given in
Table 23. The results indicate that the 16 km/h-1.5 second impact had
statistically significant less displacement than both the higher speed
tests at target A1.
---------------------------------------------------------------------------

\57\ The one sided t-test was performed assuming equal variance
to determine if the 24 km/h impact produced larger displacement
values compared to the 20 km/h impact.

Table 23--New Impactor, Comparison of Target A1 Displacement as a Function of Impact Velocity
----------------------------------------------------------------------------------------------------------------
Vehicle CX9 Edge
----------------------------------------------------------------------------------------------------------------
Test Type 16 km/h-6 sec. 24 km/h-1.5 sec. 16 km/h-6 sec. 20 km/h-1.5 sec.
----------------------------------------------------------------------------------------------------------------
75 110 126 152
59 113 119 143
----------------------------------------------------------------------------------------------------------------
Average......................... 67.0 111.5 122.5 147.5
Std............................. 11.3 2.1 4.9 6.4
----------------------------------------------------------------------------------------------------------------
P-Value......................... 0.016
0.024
----------------------------------------------------------------------------------------------------------------

b. Field Performance

The agency evaluated available crash data to better understand the
field performance of the current fleet equipped with side curtain air
bags. A focus of this evaluation was the performance of the rollover
sensors and their ability to detect the rollover event and activate
deployment of the side curtain air bags. We also sought to understand
the occupant containment provided by the vehicle system. Several
sources of available data were reviewed. These included detailed
analysis on a limited number of rollover crashes by NHTSA's Special
Crash Investigation (SCI) division, case reviews of NASS CDS cases from
the target population of the final rule, and data from a new Rollover
Data Special Study project. Detailed reviews of some of these cases can
be found in the technical report accompanying this final rule.
SCI Cases Presented in the NPRM
The following seven SCI cases were discussed in the NPRM. The
agency's SCI division analyzed seven real-world rollover crashes of
Ford vehicles where the subject vehicles contained a rollover sensor
and side curtain air bags. (Ford had agreed to notify SCI of the
crashes.) The subject vehicles were Ford Expeditions, a Ford Explorer,
a Mercury Mountaineer, and a Volvo XC90. Table 24 gives details about
each case.
In each case, the rollover sensor deployed the side curtain air
bag. Of the seven cases, there were a total of 19 occupants, 15 of whom
were properly restrained. All were in lap/shoulder belts, except one
child in a rear facing child restraint system (CRS). A single crash
(DS04-016) had all of the unrestrained occupants, serious injuries,
fatalities and ejections in this set of cases. Two of the four
unrestrained occupants were fully ejected from the vehicle, resulting
in one fatal and one serious injury. The fatality was a 4-month-old
infant, seated in the middle of the 2nd row. The ejection route was not
determined. The seriously injured occupant was an adult in the left 3rd
row, ejected through the uncovered right side 3rd row window. One non-
ejected, restrained occupant received a fatal cervical fracture
resulting from roof contact and another was seriously injured. The
injuries to the remaining occupants were ``none'' to ``minor.''

[[Page 3235]]

Table 24--Ford SCI Rollover Cases (Presented in the NPRM)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Occupants Deploy
Case Make Model MY ------------------------------------------------ \1/4\ Rot. ---------------------------------------------------------------------------------------
Row 1 Row 2 Row 3 Angle Time (ms) Rate (deg/s)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CA02-059........................ Mercury....... Mount......... 2002.......... 1R............ 1R............ .............. 1............. 17............ .................................. 17 to 25
CA04-010........................ Ford.......... Expl.......... 2003.......... 1R............ .............. .............. 1............. 43............ 20 75
IN-02-010....................... Ford.......... Exped......... 2003.......... 1R............ .............. .............. 2............. 45............ 146 111
2004-003-04009.................. Ford.......... Exped......... 2003.......... 1R............ 2R............ .............. 5............. Yes........... Unknown Unknown
DS04-016........................ Ford.......... Exped......... 2003.......... 2R............ 2R, 1R, 5............. Yes........... Unknown Unknown
2NR[dagger]. 2NR[dagger].
DS04017......................... Ford.......... Exped......... 2004.......... 1R............ .............. .............. 12............ Yes........... Unknown Unknown
2003-079-057.................... Volvo......... XC90.......... 2003.......... 1R............ 1R............ .............. 6............. Yes........... Unknown Unknown
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R = Restrained, NR = Not Restrained.
[dagger] One NR 2nd and 3rd row occupant ejected (total of 2 ejected).

[[Page 3236]]

Rollover Data Special Study (RODSS)
RODSS is a new source of rollover crash data that began in April
2007. NHTSA initiated RODSS as a pilot project to obtain additional
field data for rollover crashes not covered by other agency databases.
Cases were identified through the FARS database. NASS CDS and SCI cases
were excluded from consideration because detailed information from
those crashes would be available from those databases. However, remote
SCIs were performed on selected cases.\58\ The technical report for
this final rule includes a discussion of the RODSS study conducted for
this final rule.
---------------------------------------------------------------------------

\58\ A remote SCI is one where, for a variety of reasons, the
investigator is not able to physically examine the crash location
and vehicles. The investigation is done through the use of police
accident reports, scene diagrams and photographs.
---------------------------------------------------------------------------

RODSS is not a random sample and is not intended to be
statistically representative of all rollover crashes nationally. Also,
the sample size is small and becomes even smaller when separating the
data into subcategories. Accordingly, observations based on the RODSS
data about the relationship of side curtains and ejection are
inherently limited.
To become part of the RODSS sample, the vehicle had to be exposed
to a rollover crash and have a side curtain air bag and/or electronic
stability control (ESC)/rollover stability control (RSC). The curtain
air bag did not have to be deployable in a rollover, i.e., the curtain
air bag could be an FMVSS No. 214 side impact air curtain without a
rollover sensor, but some vehicles did have a rollover sensor.
The study first reviewed a total of 328 crashes occurring in 2005
through 2008. Of these 328 case vehicles, 315 were coded as exposed to
a lateral rollover. Of these 315 case vehicles, 115 were believed to be
equipped with side curtain air bags. Of these 115 case vehicles, 21
were believed to have a rollover sensor (rollover curtain). Of these 21
case vehicles, 18 had their curtains deploy during the rollover and 3
did not. These three cases of non-deployment are of interest relative
to sensor performance and will be discussed in more detail later, along
with a non-deployment SCI case.
Curtain deployment coding was tied to the driver or passenger,
i.e., if there was someone seated on the side of the vehicle where the
curtain deployed, it was coded as deployed for that occupant. There
were 120 side curtain air bags deployed adjacent to occupants of the
vehicles (58 drivers and 62 passengers). Limiting RODSS occupant
selection to those in vehicles exposed to a lateral rollover, and those
who had a known ejection status, then separating by known curtain
deployment, results in Table 25, below. This table shows 119 occupants
(57 drivers and 62 passengers) who were exposed to a curtain deployment
and 496 (244 drivers and 252 passengers), who were not.

Table 25--RODSS Driver and Passenger in Lateral Rollovers With Known
Ejection Status by Known Curtain Deployment
------------------------------------------------------------------------
All
Curtain deployment Drivers Passengers occupants
------------------------------------------------------------------------
Yes................................... 57 62 119
No.................................... 244 252 496
---------------------------------
Total............................. 301 314 615
------------------------------------------------------------------------

General Observations From RODSS About Ejection Rates Relative to
Curtain Air Bags
Again, any observations made based on the RODSS data about the
relationship of side curtains and ejection must be prefaced by the fact
that RODSS is not a random sample and is not intended to be
statistically representative of all rollover crashes nationally.
The data from the 615 occupants in Table 25 form the basis of a
comparison on ejection status versus curtain air bag deployment found
in Tables 26 and 27. The ``curtain deployed'' group is made up of
vehicles that had a rollover sensor and vehicles that did not (the
latter vehicles may have had a side impact sensor only). The ``curtain
not deployed'' group is made up of vehicles equipped or not equipped
with a curtain, i.e., one possible reason for the curtain not deploying
is that it did not exist.
We studied the data to see if side curtains had an effect in
mitigating rollover ejections. We were aware that care should be taken
in drawing conclusions from these results. Most of the curtain-equipped
vehicles exposed to lateral rollovers had only FMVSS No. 214 side
impact curtains (94 vehicles), rather than rollover curtains (21
vehicles). It is possible that if a side impact curtain deployed during
the crash, the crash might be different than a crash where a side
impact curtain did not deploy. An important difference when examining
ejection data is rollover severity as quantified by number of quarter-
turns. To help determine if there was an obvious bias in the data, we
examined the difference between the quarter-turns in the rollover
crashes where the side impact curtains deployed and the number of
quarter turns in the rollover crashes where they did not deploy.
RODSS data indicate that deployment of any curtain (even a side
impact curtain) has a positive effect on reducing the rate of side
window ejection. Table 26 shows that 10.9 percent [13/119] of all
occupants adjacent to a curtain air bag deployment were ejected through
the side windows, in comparison to 27.6 percent [137/496] of those
occupants who were not adjacent to a curtain deployment.
Restricting the data to occupants protected by a curtain deployed
by a rollover sensor, 5.3 percent [2/38] were ejected. The cases
involving the two occupants who were ejected, even though the rollover
curtain deployed, are discussed in a later section.

[[Page 3237]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.003

Table 27 examines the subset of occupants from Table 26 who were
unbelted. Table 27 shows that 22.7 percent [10/44] of unbelted
occupants in vehicles with curtain air bag deployment were ejected
through the side windows, in comparison to 51.9 percent [108/208] of
those unbelted occupants in vehicles where the curtain did not deploy.
Rollover severity (as represented by number of quarter-turns) does not
seem to account for the difference in the ejection rates for these two
unbelted groups.
When the data are restricted to only unbelted occupants protected
by rollover curtains, 10.0 percent [1/10] were ejected through the side
window, as compared to 26.5 percent [9/34] of unbelted occupants
protected by side impact curtains. We note that two unbelted occupants
were not ejected in vehicles with deployed rollover curtains.
[GRAPHIC] [TIFF OMITTED] TR19JA11.004

Cases Where Occupants Were Ejected Through Rollover Curtain-Equipped
Windows
We examined SCI rollover crashes, NASS CDS cases from the target
population of the final rule and data from the RODSS project and found
six case vehicles where occupants were ejected through the side window
opening that a rollover deployed curtain presumably covered. These
cases are listed in Table 28, along with the number of quarter turns,
occupant seating position, belt use, occupant age, degree of ejection,
ejection route, and level of injury.
The average number of quarter-turns was 5.5. These six crashes
involved nine occupants, six of whom were partially or completely
ejected through a protected side window. Four occupants were partially
ejected and two were completely ejected. All six were front seat
occupants, although one was ejected through a second row window. Four
of the ejected occupants were killed in the crash. One fatal partial
ejection was ejected through a window protected by both a curtain and a
laminated window. Four of these cases involved curtain damage. In two,
the A-pillar tether detached. It is not possible to know if these
instances of curtain damage occurred during the rollover or post-crash
due to extrication.

[[Page 3238]]

Table 28--RODSS, NASS CDS and SCI Cases With Occupants Who Were Ejected Through Side Windows Protected by Rollover Curtains
--------------------------------------------------------------------------------------------------------------------------------------------------------
1/4 Seat
Case ID Year/Make/Model Turns Curt. depl. pos. Belt use Age Eject. Route Injury/ MAIS
--------------------------------------------------------------------------------------------------------------------------------------------------------
RODSS

7238 *.................. 06 Ford Explorer... 6 Yes........... 11 No........... 84y Comp......... Row 1 L........ Fatal.
8289 *.................. 03 Lincoln Aviator 8+ Yes........... 11 Yes.......... 62y Part......... Row 1 L........ Fatal.
[Dagger].
8289 *.................. 03 Lincoln Aviator 8+ Yes........... 12 Yes.......... 28y No........... NA............. Serious.
[Dagger].
8289 *.................. 03 Lincoln Aviator. 8+ Yes........... 23 Yes.......... 65y No........... NA............. Moderate.

NASS CDS

2003-04-048 *........... 02 Ford Explorer... 4 Yes........... 11 Yes.......... 54y No........... NA............. 1.
2003-04-048............. 02 Ford Explorer... 4 Yes........... 13 Yes.......... 49y Part......... Row 1 R........ 1.
2006-79-089............. 04 Lexus RX330..... 1 Yes........... 11 No........... 27y Part......... Row 2 L........ Fatal.
2008-03-108............. 08 Honda Pilot..... 6 Yes........... 11 No........... 48y Part......... Row 1 L........ 3.
2008-12-159............. 05 Mercury Mont.... 8 Yes........... 11 No........... 23y Comp......... Row 1 L........ Fatal.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* These are also SCI cases.\59\
[Dagger] These seating positions had laminated glazing adjacent to them.

Non-Deployed Rollover Curtains in Rollover Crashes
---------------------------------------------------------------------------

\59\ Both RODSS cases were made into SCI remote investigations
to facilitate documentation of photographs and other crash details.
The SCI case numbers are CA09069 (RODSS 7238) and CA10006 (RODSS
8289).
---------------------------------------------------------------------------

We examined SCI rollover crashes, NASS CDS cases from the target
population of the final rule and data from the RODSS project to find if
the rollover sensors deployed the rollover side air curtains in a
rollover. In general, field data indicate that rollover sensors have
been recognizing a rollover and deploying rollover curtains in rollover
crashes.
We found five case vehicles where the vehicle was apparently
equipped with a side curtain air bag that was supposed to be deployed
by a rollover sensor and the curtains did not deploy in the rollover
event (see Table 29). There were two completely ejected occupants and
one partial ejected occupant in these crashes. The results of these
ejections were 3 fatalities. All of these ejections were through side
windows except one where the front passenger door was dislodged from
the vehicle and provided the ejection route for the unbelted driver.
Consistent among these non-deployment cases is that the rollover
was preceded by a significant frontal impact. Four of the five non-
deployment cases had a significant frontal impact that preceded the
rollover. The MY 2006 Ford Explorer in RODSS case 6121 had a right
front corner impact with a large tree prior to the rollover. The MY
2003 Lincoln Aviator in RODSS case 7242 had an offset frontal impact
with an oncoming vehicle prior to the rollover. The MY 2006 Cadillac
SRX in SCI case DS07009 impacted a large tree prior to the rollover.
The EDR data from this case indicated that the tree impact had a
longitudinal and lateral [Delta]V of - 38.9 mph and - 10.2 mph,
respectively. The EDR also indicated that the rollover sensor status
was ``invalid'' and the curtain deployment was not commanded. The MY
2009 Dodge Journey had a narrow offset frontal impact with another
vehicle, which the crash investigator stated disrupted the power supply
from the battery. The frontal air bags deployed in the above four
crashes. (There is some doubt as to whether RODSS case 6121 (SCI
CA9062) was definitely equipped with a rollover sensor, since the
system was an option on this vehicle. Ultimately, no definitive
determination was made.) For the cases involving initial frontal
impacts, these impacts may have destroyed the vehicle battery and thus
eliminated the primary power source for deploying the rollover curtain.
In RODSS case 5032 (SCI CA9061), it appears the sensor may not have
been able to make a determination that a rollover occurred. However, in
studying the details of this case, the vehicle's kinematics were very
complex and may have included some motion not typical of a lateral
rollover.

Table 29--RODSS and SCI Rollover Cases Where the Rollover Curtain Did Not Deploy
--------------------------------------------------------------------------------------------------------------------------------------------------------
Quarter Seat
Case ID Year/Make/Model turns Curt. depl. pos. Belt use Age Eject. Route Injury/ MAIS
--------------------------------------------------------------------------------------------------------------------------------------------------------
RODSS

5032 *.................. 04 Lincoln Aviator 3 No............ 11 No........... 68y Comp......... Row 2 R........ Fatal.
[Dagger].
6121 *.................. 06 Ford Explorer... 4 No............ 11 No........... 23y Comp......... Door (13)...... Fatal.
7242 *.................. 03 Lincoln Aviator 3 No............ 11 Yes.......... 28y No........... NA............. Serious.
[Dagger].
7242 *.................. 03 Lincoln Aviator 3 No............ 13 Yes.......... 26y No........... NA............. Serious.
[Dagger].
7242 *.................. 03 Lincoln Aviator. 3 No............ 21 CRS.......... 3y No........... NA............. Serious.
7242 *.................. 03 Lincoln Aviator. 3 No............ 23 Yes.......... 7y No........... NA............. Serious.

SCI

DS07009................. 06 Cadillac SRX.... 4 No............ 11 No........... 81y Part......... Row 1 L........ Fatal.
DS09071................. 09 Dodge Journey... 4 No............ 11 Yes.......... 63y No........... NA............. 2.
DS09071................. 09 Dodge Journey... 4 No............ 13 Yes.......... 60y No........... NA............. 1.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* These are also SCI cases.\60\
[Dagger] These seating positions had laminated glazing adjacent to them.

[[Page 3239]]

X. Response to Comments and Agency Decisions
---------------------------------------------------------------------------

\60\ These three RODSS cases were made into SCI remote
investigations to facilitate documentation of photographs and other
crash details. The SCI case numbers are RODSS 5032 (CA09061), RODSS
6121 (CA9062) and RODSS 7242 (CA9063).
---------------------------------------------------------------------------

Laboratory and field data indicate that window curtains covering
side windows can substantially reduce ejections in rollovers. NHTSA
issued the NPRM to require that the side windows next to the first
three rows of seats be subject to performance requirements that ensure
the vehicle has an ejection mitigation countermeasure that would
prevent an 18 kg headform from moving more than 100 mm beyond the zero
displacement plane of each window when the window is impacted.
The NPRM proposed requirements for: (a) The impactor dimensions and
mass; (b) the displacement limit; (c) impactor time and speed of
impact; (d) target locations, and (e) testing the targets. We also
discussed: (f) glazing issues; (g) test procedure tolerances; (h) test
device characteristics; and (i) a proposal for a telltale requirement.
The NPRM did not specifically require a rollover sensor. A 3-year lead
time and 4-year phase-in was proposed, along with allowance of advanced
credits to meet phase-in requirements. Costs, benefits, and other
impacts were discussed in a PRIA accompanying the NPRM.

a. Impactor Dimensions and Mass

1. NPRM
The component test involves use of a guided linear impactor that is
designed to replicate the loading of a 50th percentile male occupant's
head and upper torso during ejection situations. The portion of the
impactor that strikes the countermeasure is a featureless headform that
was originally designed for the upper interior head protection research
program (FMVSS No. 201).\61\ It averages the dimensional and inertial
characteristics of the frontal and lateral regions of the head into a
single headform. The NPRM specified that the headform is covered with
an approximately 10 mm thick dummy skin material whose outer surface
dimensions are given in Figure 4, below. The Technical Analysis report
accompanying the NPRM discusses other dimensional attributes of the
headform, such as the curvature of the outer surface.
---------------------------------------------------------------------------

\61\ ``Ejection Mitigation Using Advanced Glazings: A Status
Report,'' November 1995, Docket NHTSA-1996-1782-3; ``Ejection
Mitigation Using Advanced Glazings: Status Report II,'' August 1999,
Docket NHTSA-1996-1782-21; ``Ejection Mitigation Using Advanced
Glazings: Final Report,'' August 2001, Docket NHTSA-1996-1782-22.
---------------------------------------------------------------------------

There are many possible ways of delivering the impactor to the
target location on the ejection mitigation countermeasure. Both the old
and new impactors used in agency research propel the shaft component of
the impactor with a pneumatic piston. The shaft of the old impactor
slides along a plastic (polyethylene) bearing. The new impactor uses
curved roller bearings for part of the shaft support, which reduces the
energy loss due to friction. The impactor has an 18 kg mass.\62\
---------------------------------------------------------------------------

\62\ Since the performance criterion for this ejection
mitigation standard is a linear displacement measure (a linear
displacement measure would correlate to the actual gap through which
an occupant can be ejected), a linear impactor is a suitable tool to
dynamically measure displacement. The impactor can be placed inside
the vehicle for testing the ejection mitigation curtains and glazing
covering window openings.
[GRAPHIC] [TIFF OMITTED] TR19JA11.005

[[Page 3240]]

The mass of the guided impactor was developed through pendulum
tests, side impact sled tests, and modeling conducted to determine the
mass imposed on the window opening by a 50th percentile adult male's
upper torso and head during an occupant ejection (``effective
mass'').\63\ Briefly, the pendulum impact tests were conducted on a
BioSID anthropomorphic test device (50th percentile adult male) to
measure effective mass of the head, shoulder, and upper torso. The
BioSID was chosen because it was originally configured for side impact,
unlike the Hybrid III dummy, and has a shoulder which the Side Impact
Dummy (49 CFR 572, subpart F) used for FMVSS No. 214, ``Side impact
protection,'' does not have. A linear impact pendulum weighing 23.4 kg
was used to strike the head and shoulder of the dummy laterally
(perpendicular to the midsagittal plane) using two impact speeds (9.7
and 12.9 km/h) and four impact surfaces. In addition to the rigid
impactor face, three types of padding were added to the impactor face
to increase the contact time and replicate advanced glazing impacts.
---------------------------------------------------------------------------

\63\ ``Technical Analysis in Support of a Notice of Proposed
Rulemaking for Ejection Mitigation,'' supra.
---------------------------------------------------------------------------

Effective mass was calculated by dividing the force time history
calculated from the pendulum accelerometers by the acceleration time
history from the dummy sensors. In general, higher speed impacts and
impacts with softer surfaces generated higher effective mass. Based on
these pendulum tests, a range for the effective mass of the head and
upper torso was estimated to be 16 to 27 kg.
In the sled tests, we used a side impact sled buck with a load
plate representing a door and two load plates representing the glazing
to measure shoulder and head impacts with three different stiffness
foams. The purpose of these tests was to determine the effect lower
body loading would have on the combined head and upper torso effective
mass. Two impact conditions were simulated, one condition was described
as being representative of a rollover event and the second was
described as being representative of a side impact event.
In the rollover condition, the impact speed was intended to be 16.1
km/h (10 mph) and the dummy was positioned leaning towards the door
such that the head and torso would contact the simulated glazing at the
same time. This leaning position was intended to be more representative
of an occupant's attitude in a rollover. For the test designed to be
more representative of a side impact condition, the dummy was seated
upright and the impact speed was intended to be 24.1 km/h (15 mph).
In the preamble of the NPRM, we described the agency's analysis of
these tests as follows. As was done for the pendulum data, the
effective mass was calculated by dividing the force time history
calculated from the pendulum accelerometers by the acceleration time
history from the dummy sensors. Using this method, the effective mass
of the head and upper torso calculated for the 16.1 km/h impact
condition showed a quick rise to about 18 kg by about 5 ms, followed by
an increase to about 40 kg at about 30 ms. The effective mass for the
24.1 km/h impact condition showed an initial artificially high value or
spike prior to 5 ms because of a lag between the force measured in the
load plates and the acceleration measured at the upper spine. This
spike was also seen in some pendulum shoulder impacts. The effective
mass settled to about 9 kg at about 10 ms, with a slow rise to about 18
to 20 kg at about 25 to 30 ms. Looking at the results, we deferred to
the 18 kg effective mass since the test condition more closely
represented a rollover. In addition, the 18 kg value was within the
range of the pendulum impactor results discussed above, which showed an
effective mass range between 16 and 27 kg.
For this final rule, we have reanalyzed these sled tests primarily
for the purpose of determining impact energy, which we address in
detail later in this preamble.\64\ However, this analysis also
generated estimates of the effective mass of the dummies in these
tests. For the 24.1 km/h test, three methods (represented by equations
2-4, infra) gave a range of the combined head and shoulder effective
mass of 12.2 to 13.1 kg. We believe that a reasonable estimate is 13
kg. The analysis for the 16.1 km/h test is more complex due to the time
dependent dummy orientation. After making estimates of the impact
energy using a simple sprung mass model, we back calculated the
effective mass assuming the impact energy is equal to the kinetic
energy prior to impact (represented by equation 3, infra). We also used
the sled velocity as a surrogate for relative dummy speed and
calculated effective mass directly by using an equation 4, infra. From
these calculations we estimated a combined head and shoulder effective
mass of 22 kg.
---------------------------------------------------------------------------

\64\ The video from these tests and the data from the dummies,
load wall and sled can be accessed from the NHTSA Biomechanics
Database at http://www-nrd.nhtsa.dot.gov/database/aspx/biodb/querytesttable.aspx. The test numbers are 10282 through 10287. Tests
reanalyzed in detail were 10282 (24 km/h test) and 10285 (16.1 km/h
test).
---------------------------------------------------------------------------

In the NPRM preamble, we reported that the agency also performed a
computer modeling analysis of an 18 kg impactor and 50th percentile
Hybrid III dummy impacting simulated glazing (foam). The comparison
found that the total energy transferred by the 18 kg impactor was
within the range of the total energy transferred by the entire dummy.
For a 16.1 km/h dummy model impact with the foam, the effective mass
that came in contact with the foam was between 12.5 kg and 27 kg.
We noted in the NPRM that the 18 kg proposed mass is consistent
with that used by General Motors (GM) in 16.2 km/h (10 mph) tests of
ejection mitigation curtains.\65\ GM based this value on test results
from 52 full-vehicle rollover tests that estimated the effective mass
of occupant contact with the first row side window area. A more
detailed analysis of this study can be found later in this preamble.
---------------------------------------------------------------------------

\65\ O'Brian-Mitchell, Bridget M., Lange, Robert C., ``Ejection
Mitigation in Rollover Events--Component Test Development,'' SAE
2007-01-0374.
---------------------------------------------------------------------------

The estimated effective mass for most belted tests was about 5 kg
and all were less than 10 kg. The majority of belted tests had
effective masses which were a combination of both the near and far side
occupants. The effective mass for the unbelted occupants ranged from 5
to 85 kg.
In summary, the proposed impactor mass was based on the
determination of an effective mass calculated through both pendulum and
sled test impacts and modeling. These methods resulted in a large range
of effective mass values. In the end, we deferred to the 18 kg
equivalent mass seen during the sled test that was intended to be more
representative of a rollover event, which was also the equivalent mass
calculated from pendulum impact into the dummy shoulder. For this final
rule we have reanalyzed the sled tests and estimated a range of
effective mass from approximately 13 to 22 kg. Thus, the 18 kg
effective mass is still considered to be a reasonable representation of
an occupant's head and a portion of the torso. An effective mass more
representative of just the head would be substantially smaller, and an
equivalent mass accounting for more torso and lower body mass would be
substantially more. The 18 kg mass is well within the GM estimates from
vehicle rollover tests, and is consistent with the impactor that GM
uses to evaluate side curtains.

[[Page 3241]]

2. Comments
There was general support from the vehicle manufacturers and
suppliers for using a linear impactor and performance metric based on
the displacement of that impactor in a compliance test. There were only
a few comments on the impactor dimensions and mass. These few comments
were in favor of the proposed mass. While VW and others had comments on
the impact energy imparted by the mass, which is an issue which will be
addressed in a later section below, VW stated that ``the 18 kg mass for
the impactor is well established * * *'' The Alliance referenced the
fact that the GM test procedure for ejection mitigation uses an 18 kg
linear impactor in stating that ``[t]he Alliance supports the use of
the 18 kg headform proposed in the NPRM.''
Some parties commented on the design of the headform. Takata stated
that simulated animations have shown relative movement of head skull
and headform, and that ``the incomplete fixation of the head skull is
influencing the displacement behavior of the head form [sic].'' Takata
suggested enlarging the head skull fixation in the lower portion, by
adding a skull cap or enlarging the chin area in the rear for example.
Similarly, TRW said that it found that the headform skin can become
dislodged from the skull during testing and suggested using a backplate
of smaller size on the headform to better clamp the headform skin
flange to the skull. TRW also said that the headform skin can become
displaced from the lower (chin) area of the skull.
AORC recommended that NHTSA adopt specifications for the skin
stiffness, skin friction coefficient, and skull surface finish, to
address the headform skin partially dislocating on the headform as a
result of friction between the countermeasure and the headform.
TRW suggested changes to the preparation of the headform for
testing. It stated that frictional attributes of the headform skin
affect the manner in which the headform interacts with the rollover
curtain, so talc, chalk, or other coatings could affect test results.
TRW suggested that the standard specify that ``no coatings shall be
applied to the headform skin during testing'' and asked, as did AORC,
that the standard specify that prior to the test, the headform skin
must be cleaned (TRW suggested cleaning the headform with isopropyl
alcohol). TRW suggested changes to the headform drawing package to
address: The outer surface finish requirements of the skull; the
thickness tolerance and durometer hardness of the skin; inner/outer
surface finish and tolerance requirements of the skin material type and
material properties corridor for the skin; the definition of frictional
characteristics of the skin, including the performance corridor; and
test procedure and measurement technique for frictional characteristics
of skin.
3. Agency Response
We are adopting an 18 kg headform substantially similar to the
device described in the NPRM.
We are declining Takata's and TRW's requests to add a skull cap or
modify the backplate of the headform. The modification is unnecessary
as the new headform has not exhibited the problem these commenters
describe. Further, the effect of the modification on actual test
results has not been quantified by the commenters. Using modeling,
Takata estimated about a 3 mm increase in displacement between the
proposed headform and one with the suggested modification, but it is
not clear this modeling is representative of an actual impact test.
NHTSA is not inherently opposed to improvements in the headform
design to possibly allow for a longer period of head skin use before it
needs to be replaced. However, it has not been shown that there is a
need to improve the headform at this time. If improvements are feasible
and the effect of changing the headform on ejection mitigation
countermeasure performance can be better assessed, we are open to
considering fine-tuning adjustments to the headform at a future date.
With respect to TRW's comments about the additions and revisions to
the drawing package, the NPRM's drawing package already included
specifications for the skin material type, thickness and durometer. It
also included a specification for preparing the outer surface finish of
the skull. TRW did not provide any reason to change these
specifications, so they will remain as proposed in the final rule.
We deny TRW's other requests that we specify the inner/outer skin
surface finish, skin frictional characteristics, friction performance
corridor and friction measurement technique. We do not believe there is
a need for these specifications. NHTSA has not before found a need to
specify skin surface finish and frictional characteristics for test
dummy skin. The commenter provided no justification as to why the
material properties provided were insufficient or how the requested
parameters would improve the objectivity of the standard.
We are denying the request to place a requirement in the regulatory
text to clean the headform skin with isopropyl alcohol as per FMVSS No.
201, ``Occupant Protection in Interior Impact.'' The commenters provide
no data showing the necessity of such provision. FMVSS No. 201 has no
requirement that the free motion headform be cleaned with alcohol prior
to the testing. There is no FMVSS that specifies in the regulatory text
that the dummy skin should be cleaned prior to vehicle testing.

b. Measurement Plane and Displacement Limit (100 mm)

1. NPRM
We proposed that the linear travel of the impactor headform must be
limited to 100 mm from the inside of the tested vehicle's glazing as
measured with the glazing in an unbroken state. The 100 mm boundary
would be first determined with the original glazing ``in position''
(up) and unbroken. Then, for the test, the original glazing would be in
position but pre-broken if it were advanced glazing; or down or removed
altogether if it were tempered glazing. It was proposed that advanced
glazing would be in position but pre-broken for both the 1.5 second
test and the 6-second test.
The NPRM included a window-breaking procedure that damages but does
not destroy advanced glazing, while it will obliterate tempered
glazing. It was proposed that vehicle manufacturers may remove or
completely retract tempered glazing since it would be destroyed in the
pre-breaking procedure and would have no effect on the ejection
mitigation results. When tested with the original glazing in position
but pre-broken or with the glazing removed, the linear travel of the
impactor headform must not exceed the 100 mm limit. If a side curtain
air bag is present, and we anticipate that most, if not all, vehicles
will have an ejection mitigation curtain, the curtain would be
deployed.
In the test, the ejection mitigation countermeasure must prevent
the headform from exceeding the 100 mm limit. The principle underlying
the 100 mm displacement limit is to ensure that the countermeasure does
not allow gaps or openings to form through which occupants can be
partially or fully ejected. In the research tests, targets that had
displacements of less than 100 mm did not allow ejections in dynamic
testing.
In research tests, the TRW and Zodiac prototype ejection mitigation
countermeasures were tested on a CK

[[Page 3242]]

pickup to the proposed impactor test procedure.\66\ The TRW prototype
had no coverage at position A1 (front window forward lower position).
These systems were later tested on the DRF with the 50th percentile
male, 5th percentile female and 6-year-old dummies in upright seating
positions, and a prone 6-year-old dummy aimed at approximately the
target positions A1 and A2 (front window rear lower position). When
tested on the DRF, the arms of the upright dummies flailed out of the
window opening up to the shoulder at the sill (A1 and A2) and the prone
6-year-old dummy was completely ejected at A1.
---------------------------------------------------------------------------

\66\ There were only some slight variations in target locations.
---------------------------------------------------------------------------

We recognize that dummy ejection did not occur all the time at
targets that had displacements of over 100 mm. When tested with pre-
broken laminated glazing, at position A1, the TRW system had 181 mm of
displacement at the 24 km/h (1.5 second delay) test and 104 mm of
displacement in the 20 km/h (1.5 second delay) test, but did not eject
either the prone or seated dummies in DRF tests. Nonetheless, the
component and DRF testing indicated that there was an increased
likelihood that an opening could be formed between the curtain and the
window opening through which an occupant could be ejected if the
displacement were over 100 mm in the headform test. In addition, a 100-
mm limit would also help guard against the countermeasure being overly
pliable or elastic so as to allow excessive excursion of an occupant's
head and shoulders outside of the confines of the vehicle even in the
absence of a gap.\67\
---------------------------------------------------------------------------

\67\ The agency further notes that an advantage to the
displacement limit is that the linear displacement of the headform
can be measured in a practicable and relatively straightforward
manner, unlike a real-time dynamic measurement of a gap during an
impact.
---------------------------------------------------------------------------

NHTSA also noted in the NPRM that a 100-mm performance limit is
used in several regulations relating to occupant retention. In FMVSS
No. 217, ``Bus emergency exits and window retention and release,'' (49
CFR 571.217), bus manufacturers are required to ensure that each piece
of glazing and each piece of window frame be retained by its
surrounding structure in a manner that prevents the formation of any
opening large enough to admit the passage of a 100-mm diameter sphere
under a specified force. The purpose of the requirement is to minimize
the likelihood of occupants being thrown from the vehicle. This value
is also used in FMVSS No. 206, ``Door locks and door retention
components,'' (49 CFR 571.206, as amended 69 FR 75020), to mitigate
occupant ejection through unintentional door openings in a crash. In
FMVSS No. 206, the door is loaded with 18,000 N of force and the space
between the interior of the door and the exterior of the door frame
must be less than 100 mm.
In addition, NHTSA also considered that a value of approximately
100 mm is used by the International Code Council (ICC) in developing
building codes used to construct residential and commercial
buildings.\68\ The ICC 2006 International Building Code and 2006
International Residential Code require guards to be placed around areas
such as open-sided walking areas, stairs, ramps, balconies and
landings. The guards must not allow passage of a sphere, 4 inches (102
mm) in diameter, up to a height of 34 inches (864 mm). The ICC explains
in the Commentary accompanying the Codes that the 4-inch spacing was
chosen after considering information showing that the 4-inch opening
will prevent nearly all children 1 year in age or older from falling
through the guard.
---------------------------------------------------------------------------

\68\ The ICC is a nonprofit membership association that works on
developing a single set of comprehensive and coordinated national
model construction codes. http://www.iccsafe.org/news/about/.
---------------------------------------------------------------------------

The NPRM noted that GM has developed a test procedure that uses a
100 mm displacement limit but in GM's procedure, the zero displacement
plane is a plane tangent to the exterior of the side of the vehicle at
the target location.^{69 70} Displacement is measured
perpendicular to this excursion plane. Thus, the allowable GM
displacement is approximately 100/cos([thgr]) mm, with [thgr] being the
angle with the vertical of the exterior plane, if other aspects of the
test were identical to those of the NPRM. If [thgr] were 20 degrees,
the GM limit would be approximately 106 mm. The GM method also results
in a slightly different allowable final displacement position than the
proposed method because of the separation between the flat excursion
plane and the inside surface of the window at the target location.
---------------------------------------------------------------------------

\69\ O'Brian-Mitchell, Bridget M., Lange, Robert C., ``Ejection
Mitigation in Rollover Events--Component Test Development,'' SAE
2007-01-0374.
\70\ GM explained that its justification for the 100 mm
displacement limit is that it represents half the height of the 50th
percentile male Hybrid III head.
---------------------------------------------------------------------------

2. Comments
There was general support for the use of a linear impactor as
opposed to some other impacting device and performance metric based on
the displacement of that impactor.\71\ However, many commenters had
opinions about the 100 mm performance limit and how the displacement
should be measured. In general, the net effect of the vehicle
manufacturers' requests was to increase the allowable displacement,
while that of the glazing manufacturers and consumer groups was to
reduce it.
---------------------------------------------------------------------------

\71\ This is aside from commenters who want the agency to use a
completely different test method, i.e., full vehicle dynamic
rollover.
---------------------------------------------------------------------------

Both the Alliance and AIAM suggested that the final rule measure
displacement from an initial reference point other than the point of
contact of the headform with the glazing. Both requested that a method
similar to that used by GM be used. This measurement method defines a
line tangent to the side of the vehicle at the window opening. (We note
that although the Alliance calls the longitudinal plane that passes
through this line the excursion plane, see Figure 5, extracted from the
Alliance comments, there would likely be a unique excursion plane at
every target location due to the curvature of the vehicle sides.)
Under the Alliance method, the headform contact with the excursion
plane for that target location defines the point of zero displacement.
The Alliance explained this zero plane by stating that ``the risk of
injury is more closely tied to the amount of occupant excursion from
the outside of the vehicle's structure as opposed to the side glass.''
The AIAM stated that its procedure ``takes into account the shape of
the vehicle body near the side windows and the contribution the body
makes in providing additional space before the occupant contacts the
ground.''
The Alliance and AIAM methods differ after the zero excursion plane
is determined. For the Alliance, the maximum excursion plane is defined
by translating the excursion plane 150 mm laterally. The point of
contact of the headform with the maximum excursion plane provides the
limit on displacement. The Alliance justifies its request for a 150 mm
excursion limit by stating ``that the impactor mass and impact energy
are based on the 50th male.'' Therefore, it believes that ``a 150 mm
excursion limit based on the diameter of a 50th percentile male head
(Hybrid III--153 mm, WorldSID = 159 mm, Featureless = 177 mm) is more
appropriate.'' The Alliance and Volvo commented that excursion should
not be based on the size of a child's head and impact energy of an
adult male. For the AIAM, the maximum excursion plane is defined by
translating the

[[Page 3243]]

excursion plane by 100 mm along a line normal to the excursion plane,
rather than 150 mm laterally.
[GRAPHIC] [TIFF OMITTED] TR19JA11.006

Honda agreed with the 100 mm displacement limit in the NPRM because
it believes it to be appropriate to account for the size of a child's
head. It also agreed that the horizontal measurement of the impactor
displacement was appropriate because of its ``feasibility and
measurement accuracy.'' However, Honda concluded ``that the proposed
procedure * * * doesn't accurately simulate the degree of ejection
toward the outside of the vehicle.''
Honda suggested that the measured displacement should begin at the
same location as proposed in the NPRM, i.e., the point of contact of
the headform with the inside surface of the glazing. However, Honda
suggested drawing a line normal to the glazing at the target
center.\72\ The window cross-section in the lateral plane is then
projected 100 mm along the normal line. The headform is then translated
laterally and horizontally until it contacts the projected window
cross-section, which provides the limit of displacement.
---------------------------------------------------------------------------

\72\ Honda's diagram in its comment shows a line projected from
the point of contact with the window, rather than the target center.
(The target or target outline was defined in the NPRM as the x-z
plane projection of the ejection headform face. The center of the
target outline would be the target center.) We assume the graphic
represents the intent of Honda's comment. The line emanates from the
point of glazing contact with the headform. Honda also stated that
the line projected from the point of contact is normal
(perpendicular) to the window. However, most side windows curve out
of the longitudinal vehicle plane and any normal to the window would
not be contained in a lateral plane. Thus, we have assumed that only
the component of the normal line in the lateral plane is of
interest, i.e., only the line normal to the lateral cross-section of
the glazing.
---------------------------------------------------------------------------

TRW agreed with the measurement method and excursion limit of 100
mm, with one caveat. The commenter noted that ``during an impact test,
there can be considerable deflection of the door/window frame, door
structure, door hinges, etc.'' TRW stated that ``[s]ince the objective
of the Standard is to limit headform displacement to no more than 100mm
beyond the zero displacement plane, movement of the plane due to the
door system deflection should be considered during the test.''
IIHS suggested that the 100 mm displacement limit might be
unnecessarily small. It stated that ``[s]electing this value based on
its use in other safety standards with very different test conditions
or in building codes for guardrails on balconies and stairs may be
unreasonable.'' IIHS indicated that the 12 vehicles tested by NHTSA, as
reported in the NPRM, would have failed to comply with the 100 mm
displacement limit, yet ``the crash performance of these vehicles has
not been assessed to demonstrate a need for improved ejection
mitigation systems.'' IIHS also stated that the potential negative
effects of requiring air bags to be stiffer to meet a 100 mm
displacement requirement are unknown.
In general, glazing suppliers recommended that the final rule use
the passage of a 40 mm sphere to assess any gaps in the
countermeasures. They suggested we use industry standards published by
the Society of Automotive Engineers (SAE), SAE J2568, ``Intrusion
Resistance of Safety Glazing Systems for Road Vehicles,'' or by the
British Standards Institution (BSI), BSI AU 209, ``Vehicle Security,''
which provide glazing intrusion resistance requirements from external
impact (as opposed to ejection mitigation). These industry standards
specify that after testing there must not be separation within the
glazing or between the glazing and vehicle body that would allow for
passage of a 40 mm diameter sphere. The EPGAA stated that it is
necessary to ``specify a maximum opening after impact in addition to an
excursion limit to adequately address the remaining gaps leading to
partial ejections.'' It goes on to state that ``NHTSA currently
requires gap quantification limitation for windshields to resist
occupant ejection in FMVSS [No.] 205, which mandates compliance with
ANSI/SAE Z26.1 where glazing tears are measured and limited after
impact.'' In contrast, Batzer and Ziejewski indicated that the 100 mm
displacement appeared appropriate.

[[Page 3244]]

Advocates suggested that the proposed displacement limit be reduced
by 50 percent, to 50 mm. It stated that a 100 mm displacement limit
``allows enough excursion to permit serious injuries and deaths outside
the vehicles. The 4-inch limit also devalues the major contribution
that advanced glazing can make to reduce the chances of occupant
ejections, including excessive occupant excursion outside side
windows.''
3. Agency Response
NHTSA does not agree with the requested changes to the displacement
measurement method from the vehicle manufacturers and TRW, which would
all effectively increase the allowable displacement. We also disagree
with the additional post-impact gap measurement suggested by the
glazing suppliers. We also do not concur with the requests of some
commenters to increase the displacement limit, and of some to reduce
it. We believe that the 100 mm limit strikes the appropriate balance
between stringency and practicability. We address the issue of
stringency and practicability further in a later section on the time
delay of the impacts and impactor velocity.
Suggested Methods Would Increase the Displacement Limit
We do not believe that the methods suggested by the commenters
provide a better method of measuring the performance of the ejection
countermeasure. No data was presented to support why the suggested
methods are preferable to the method proposed in the NPRM.
In the NPRM and the technical analysis supporting the NPRM, the
agency estimated that the GM measurement method allowed about 6 percent
more displacement than the proposed method of measurement. Below we
analyze the displacement measurement methods requested by the
commenters and compare the associated performance limits of the
respective methods to the performance limit discussed in the NPRM. For
this comparison, we used a graphical representation of a two
dimensional lateral cross-section of the headform contact with the side
window. For convenience, we used an approximation of the headform
profile rather than the exact cubic equation prescribed in the NPRM.
The vehicle cross-section included the window as well as the structure
in its vicinity.
Figure 6 shows how the 100 mm displacement put forward in the NPRM
is measured from the contact point of the headform at the A2 target
point with the side window glazing. In this example, the lateral cross-
section A-A of the glazing is represented by a 15 degree arc segment
having a 201 cm radius, with the base of the arc oriented approximately
7 degrees from the vertical.
[GRAPHIC] [TIFF OMITTED] TR19JA11.007

Figure 7 shows the displacement measurement methods that Honda and
the Alliance recommended in their comments. In the Honda method, the
lateral cross-section of the glazing is projected 100 mm along the
normal line at the point of contact of the headform. Using the Honda
method, the headform's horizontal displacement at the A2 target is 101
mm from the NPRM zero displacement point. The Alliance-recommended
measurement method defines a line tangent to the side of the vehicle at
the window opening as the zero excursion plane. The maximum excursion
plane is defined by translating the excursion plane 150 mm laterally.
Using the Alliance method, the headform's horizontal displacement at
the A2 target is 161 mm from the NPRM zero displacement point. This 161
mm value is the sum of the 11 mm distance between the contact point
with the window and the excursion plane ([Delta] excursion plane) and
the 150 mm

[[Page 3245]]

additional displacement to the maximum excursion plane.\73\
---------------------------------------------------------------------------

\73\ In doing this analysis, we have assumed that the point of
contact with the glazing is along the centerline of the headform. If
we did not, the difference between the NPRM method and the Alliance
and AIAM proposals would be even greater.
[GRAPHIC] [TIFF OMITTED] TR19JA11.008

AIAM also recommended a displacement measurement method similar to
the Alliance method in that an excursion plane is located tangent to
the side of the vehicle window opening. However, the maximum excursion
plane is defined by translating the excursion plane by 100 mm along a
line normal to the excursion plane rather than 150 mm laterally.
Because of the similarities between the Alliance and AIAM methods,
once the angle of the excursion plane is known, a simple mathematical
relationship can be used to calculate the AIAM displacement limit with
respect to the NPRM measurement method from the limit determined by the
Alliance method. From Figure 7 we see that the excursion angle is 17
degrees from the vertical. Thus, the horizontal translation of the AIAM
maximum excursion plane is 105 mm = 100/cos(17 deg.). The total AIAM
displacement allowance from the headform when in contact with the
window plane is the sum of the [Delta] Excursion Plane (11 mm) plus the
horizontal translation of the excursion plane (105 mm), resulting in a
value of 116 mm at target A2.
The displacement measurement methods suggested by Honda, the
Alliance, and AIAM are all more sensitive to the particular target
location, the curvature and angle of the window, as well as the profile
of the vehicle structure around the window opening, than the NPRM
method. Figure 8 shows the NPRM displacement measurement at target A4
for a side window having twice the base angle (13 degrees) as the
previous example. The window curvature remains the same. Figure 9 shows
a graphical determination of displacement measurements for Honda (109
mm) and the Alliance (156 mm) at A4. Using the mathematical
transformation described above, we calculate the AIAM value (114 mm).

[[Page 3246]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.009

[GRAPHIC] [TIFF OMITTED] TR19JA11.010

The same exercise was performed for target position A2 with a 13
degree window and for target position A4 with a 7 degree window. Figure
10 shows the displacement limits calculated for the three commenters'
methods at target positions A2 and A4 with a 7 and 13 degree window,
subtracted from the 100 mm limit in the NPRM. The Honda

[[Page 3247]]

method provides the smallest differential with the NPRM method (1 to 9
mm), the Alliance method provides the largest (55 to 61 mm). Again, the
results will vary for other target locations and window/vehicle
geometries. However, there does not appear to be a situation where any
of the suggested methods will result in a lateral displacement limit of
less than 100 mm. That is, each suggested method would reduce the
stringency of the test by permitting the openings to be greater than
100 mm. As explained in the section below, this we cannot accept.
[GRAPHIC] [TIFF OMITTED] TR19JA11.011

TRW requested allowing the zero reference plane to move with the
door frame. We are declining this request. It is unclear to us why
allowing the reference plane to move in the manner suggested is
preferable from a safety standpoint than simply maintaining the
position of the zero plane with respect to ground. The latter (NPRM)
method is preferable because the door frame provides a reaction surface
for the curtain air bags or advanced glazing. The door frame is part of
the system designed to retain the occupant in the vehicle. If the zero
reference plane is tied to movement of the door frame, a weak door
frame could render the displacement limit meaningless. For example,
under the TRW method, a vehicle that allows an impactor displacement of
150 mm with 50 mm of door deflection would be considered compliant, as
would a vehicle that allows an impactor displacement of 100 mm with 0
mm of door deflection.
Further, the TRW suggestion would also add a significant amount of
complexity to the testing. There would need to be a determination as to
the sufficient number of measurement locations on the door and how the
agency would assess movement of the door frame. The suggestion requires
further study to properly integrate it into the test procedure and we
are unable to conclude that use of our resources to pursue the matter
would be warranted.
Unrealistic Assumptions
The methods of measurement suggested by the Alliance, AIAM and
Honda are dependent on assumptions about the performance of the vehicle
that may not be realistic. The Alliance and AIAM methods are very
similar. Both these methods use a tangent to the side of the vehicle
(zero excursion plane), translated some distance, as the limit of
displacement (maximum excursion plane). The assumption apparently is
that occupant excursions within this zone will be protected.
We do not agree with this assumption. For example, if vehicle A's
exterior skin protrudes farther outboard than vehicle B's, but A's
protruding exterior skin consists of only sheet metal or plastic or

[[Page 3248]]

some like material that provides little if any crush resistance, we do
not agree that A's maximum excursion plane should be farther outboard
at the bottom of the window opening than B's. More displacement of the
headform would be permitted for vehicle A even though in a real-world
crash, A's exterior skin could be easily leveled. Since the
countermeasure of A would be permitted to allow more headform
displacement outside of the window plane than that of B, the suggested
approach would provide A's occupants less minimal protection in a
rollover or side impact than the NPRM approach.
Relatedly, when the excursion plane is derived from the undeformed
vehicle structure, if the roof structure has significant lateral
deformation after impact, the original excursion plane may have very
little relevance to occupant protection.
With Honda's method, it seems there is an underlying assumption
that if ground contact occurs with the vehicle rotated 90 degrees, the
door structure will be the initial point of contact, so that targets
near the upper part of the glazing on a vehicle with a highly inclined/
curved glazing could be permitted to displace farther than targets at
the center. Under this method, the greater the inclination and/or
curvature of the glazing in the lateral plane, the more displacement is
allowed compared to the NPRM's approach (9 percent more at A4 with the
13 degree glazing). A vehicle with a more highly inclined glazing would
be allowed more headform displacement at the top and bottom of the
window compared to the NPRM. Given the unpredictable nature of rollover
crashes, we cannot agree with this assumption. A vehicle might be
rotated greater than 90 degrees during ground contact, resulting in
initial contact near the upper glazing. Thus, to allow more
displacement at the top of the glazing relative to the initial glazing
position does not seem warranted.
Adding Complexity
The measurement methods suggested by the Alliance, AIAM, Honda and
TRW are more complicated to implement than the method proposed by the
agency. The NPRM's method of measuring displacement is actually very
simple and straightforward. The point of zero displacement is simply
the contact point with the side window glazing. From there, it is only
necessary to keep track of how far the linear impactor translates along
its axis of motion. No digitization or CAD techniques are required. To
find the zero displacement point for the Alliance or AIAM method, one
must hold a relatively thin straight edge in a lateral vehicle plane,
aligned with the target center, against the outside of the vehicle.
Headform contact with this straight edge defines the point of zero
displacement. This can be done by digitizing the exterior of the
vehicle. However, it is somewhat more onerous than the NPRM method. The
Honda method is just as simple as the NPRM method in finding the point
of zero displacement, but after that, we believe the method would
require a digitization of the glazing. This digitized glazing would
then need to be manipulated in a CAD program to determine the allowable
displacement. The complexity of the TRW method has been discussed
above.
Increasing the Displacement Limit
The agency is declining the requests to increase the allowable
displacement limit.
The Alliance and Volvo believe the limit should not be based on the
size of a child's head and the impact energy of an adult male. (In
contrast, Honda commented that basing the requirement on the size of a
child's head was appropriate.) We disagree with the Alliance and Volvo
on this point. It is reasonable for the agency to adopt a displacement
limit based on the anthropometry of a child since the standard is
intended to mitigate ejection of all sizes of occupants, not just the
mid-size male. It is possible for a child occupant to interact with an
ejection mitigation countermeasure with relatively high impact energy
if a large portion of their mass is considered. For example, an average
5-year-old child weighs about 18 kg (the same mass as the linear
impactor). Due to the size of this child relative to a window opening,
it would be much easier for their entire body mass to interact with the
window opening than it would be for an adult. Also, the ejection
mitigation countermeasure could be double-loaded by more than one
occupant simultaneously during the rollover event, e.g., a child in the
rear seat and the driver in the front seat or two unbelted occupants in
the same row. The 100 mm limit reduces the likelihood that openings
will form during the rollover that are large enough to pass the head or
other body part of a child or an adult.
The principle underlying the 100 mm displacement limit is to ensure
that the entire window opening is covered, and covered by a
countermeasure resilient enough to withstand the forces that could be
imposed on it in a rollover without forming gaps or openings.\74\ We
chose a 100 mm displacement limit as a reasonable and objective measure
of acceptable performance, taking into account the practicability of
meeting the displacement limit, safety need, and the SAFETEA-LU goal of
a standard that reduces complete and partial ejections of vehicle
occupants. We adopt a displacement limit that will ensure that the
countermeasure covering the entire window is wide enough and strong
enough to mitigate ejection of a child's head, limb or body, or those
of an adult, in the chaotic and unpredictable phases of a rollover.
---------------------------------------------------------------------------

\74\ 74 FR 63193.
---------------------------------------------------------------------------

IIHS believed that the NPRM selection of 100 mm displacement,
partially based on other standards (FMVSS Nos. 206 and 217) and
building codes, may be unreasonable. It noted that the vehicle testing
reported in the NPRM did not show any that passed all the target points
at 100 mm of displacement even though the field performance of these
vehicles may be acceptable. IIHS stated that if the displacement
requirement is too stringent it will lead manufacturers to make their
air bags too stiff, with unknown consequences from this increased
stiffness.
We understand the merits of having extensive field data that
correlates the performance in the proposed test against ejection
mitigation in the field. At the time of the NPRM development, there
were very few rollover curtain-equipped vehicles in the available field
data and the vehicles then-tested by the agency were not designed to
have full window coverage as the NPRM requirements contemplated. Now
more field data is available to us, and we have tested many more
vehicles some of which have been designed to have extensive window
opening coverage. However, the data set is still insufficient to
correlate various displacement values and field performance.
Nonetheless, we do not accept IIHS's argument that the 100 mm value
may be unreasonable because the value is used in FMVSS No. 206 and 217
and in the architectural code. These other standards and the
architectural code referenced by the agency have basically the same
purpose: retaining occupants, including children, in a vehicle in a
crash event, or retaining children behind a barrier (railing). These
precedents are supportive of the selected value. They were developed
taking into consideration the size of children's heads and limbs and
the ease or difficulty with which the parts can fit through openings.
If the window opening countermeasure can limit the

[[Page 3249]]

opening to 100 mm when impacted by the headform at the prescribed
velocities, the countermeasure is more likely to be able to restrict
the opening as needed when impacted by a lower mass at the same or
higher velocity, or the same or larger mass at a lower velocity.
Requests to Decrease Displacement Limit
Advocates suggested that the proposed displacement limit be reduced
by 50 percent to 50 mm. It believed that such a stringent requirement
will ``ensure dramatic reductions in occupant ejection, including
partial ejection * * *.'' It stated further that the proposed 100 mm
value ``devalues the major contribution that advanced glazing can
make'' and that more lives would be saved by ``a standard that
effectively would encourage the use of advanced glazing in combination
with air curtains * * *.'' \75\ The suggestion to reduce the
displacement limit was made by other commenters as well, including
glazing manufacturers.
---------------------------------------------------------------------------

\75\ NHTSA-2009-0183-0022, p. 3.
---------------------------------------------------------------------------

NHTSA does not believe that the level of stringency requested by
Advocates and others is warranted. We believe that the 100 mm limit
will be highly effective in the reduction of both complete and partial
ejections. Certainly, ejections will continue in situations where the
severity of the crash and resulting occupant energy will overwhelm the
capacity of the countermeasure. However, the 100 mm limit strikes the
appropriate balance between stringency and practicability.
There is no available data that can correlate various displacement
values with field performance at this time. We cannot conclude that
reducing the displacement limit by 50 percent will reduce ejection or
side impact fatalities and injuries by a corresponding amount. The
commenters did not provide data on this issue. On the other hand, we
can estimate possible costs of indirectly requiring advanced glazing to
be installed at side windows to meet a 50 mm displacement limit. In the
FRIA, we estimated that the incremental difference in costs for going
from tempered glass to laminated advanced glazing for a standard size
side window in the first or row is $15. Thus, for a two row vehicle the
total incremental cost would be $60. In addition, we believe that any
costs associated with advanced glazing must be combined with the
curtain bag incremental cost since a system with movable advanced
glazing alone would not be able to perform to the level required for
this standard. In comparison, the agency has determined that
incremental cost of meeting the final rule with only curtain air bags
will be $31 dollars per vehicle. The cost per equivalent fatality of a
system comprised of a partial curtain in combination with laminated
glazing was twice that of a system utilizing only a curtain.
Requests To Add Another Requirement
Many glazing manufacturers were in favor of applying an additional
post-impact requirement in which a 40 mm sphere is used to determine
the size of any remaining gaps. According to the commenters, this
requirement would be intended to eliminate gaps that can exacerbate
partial ejections. It is our interpretation of the comments that this
test is to be applied to all vehicles, i.e., those using a combination
of advanced glazing and side curtain air bags to meet the standard, and
those using only side curtain air bags.
We do not agree with this suggestion. First, the requirement is not
appropriate for vehicles with only side curtain air bags, given that
there is a time dependence associated with a curtain's ejection
mitigation performance. Once deployed, the pressure in the air bag
continuously decreases. The 16 km/h test is done at 6 seconds to assure
that the pressure does not decrease too quickly. It does not seem that
the 40 mm gap test could be done after the 6-second impact, in any
timeframe which is related to rollover and side impact ejections.
Second, there is no shown safety need for the requirement. We cannot
show that ejections that would not be prevented by the primary 100-mm
displacement requirement would be prevented by a secondary 40-mm
requirement. Third, it would seem that the 40-mm requirement would
indirectly require installation of advanced glazing. As discussed
above, the costs associated with advanced glazing installations at the
side windows covered by this standard are substantial in comparison to
a system only utilizing rollover curtains. For these reasons, the
agency does not accept this suggestion.

c. Times and Speed at Which the Headform Impacts the Countermeasure

We have determined that there is a need for a relatively high speed
impact shortly after countermeasure deployment and a lower speed impact
late in the deployment. The two time delays correspond to relatively
early and late times in a rollover event.\76\ The first impact is at 20
km/h, and at 1.5 seconds after countermeasure deployment (1.5 second
time delay). (The 20 km/h speed is reduced from the NPRM's proposal of
24 km/h; the rationale for which is discussed later in this preamble.)
The second is a 16 km/h impact initiated 6 seconds after deployment.
---------------------------------------------------------------------------

\76\ Each impact takes place on a test specimen (e.g., a
curtain) that was not previously subject to an impact test.
---------------------------------------------------------------------------

1. Time Delay (Ejections Can Occur Both Early and Late in the Rollover
Event)
i. NPRM
Two impacts were proposed because ejections can occur both early
and late in the rollover event. In the advanced glazing program, NHTSA
performed a series of simulations to recreate three NASS-investigated
rollover crashes with ejected occupants.\77\ The vehicles were a MY
1991 Toyota pickup, a MY 1986 Toyota Corolla and a MY 1985 Volkswagen
Jetta.\78\ Vehicle handling simulation software \79\ reconstructed the
vehicle motion up to the point where the vehicle started to roll. The
linear and angular velocity at the end of the vehicle handling
simulation was then used as input to a MADYMO \80\ lumped parameter
model of the vehicle to compute its complete rollover motion. The
motion of the vehicle obtained from the MADYMO vehicle model was used
as input to a MADYMO occupant simulation. Head and torso velocities of
a Hybrid III 50th percentile male driver dummy were calculated for the
three rollover simulations.
---------------------------------------------------------------------------

\77\ ``Ejection Mitigation Using Advanced Glazings: A Status
Report,'' November 1995, Docket NHTSA-1996-1782-3. Pg. 6-1.
\78\ The circumstances of the Toyota pickup rollover was that
the vehicle was traveling at 96 km/h and went into a sharp turn and
yaw, which resulted in a rollover. In the case of the Corolla, it
was also traveling 96 km/h on a gravel road. The vehicle went out of
control and left the road, resulting in roll initiation. The
Volkswagen was traveling at 88 km/h when the driver fell asleep and
the vehicle left the road. It struck a rock embankment and rolled
over.
\79\ VDANL software user's manual V2.34, STI, 1992.
\80\ MADYMO user's manual V5.1, TNO, 1994.
---------------------------------------------------------------------------

Table 30 shows the simulation resultant head velocity through the
open window at the time of ejection. As indicated in the table, for the
unrestrained simulations, the occupant of the pickup was completely
ejected early (1st quarter-turn for Toyota truck) while the occupants
of the other vehicles were ejected late (last quarter-turn for Corolla
and Jetta) in the rollover event.

[[Page 3250]]

Table 30--Head and Torso Velocities of a Hybrid III 50th Percentile Male Dummy in 3 Rollover Simulations
----------------------------------------------------------------------------------------------------------------
\1/4\ Turns Head to Head to Torso to
Vehicle Vehicle \1/ at complete Restraint use opening (km/ glazing (km/ glazing (km/
4\ turns ejection h) h) h)
----------------------------------------------------------------------------------------------------------------
Toyota PU.................... 12 ........... Yes............. 20 20 7
........... 1 No.............. 5 20 16
Toyota Corolla (86).......... 6 ........... Yes............. 15 15 11
........... 6 No.............. 13 13 10
Volkswagen Jetta (85)........ 4 ........... Yes............. 14 14 10
........... 4 No.............. 22 18 16
----------------------------------------------------------------------------------------------------------------

The agency also considered other data indicating that very early
occupant contact with the window area is possible in rollover crashes.
Table 31 gives information on 30 rollover tests the agency performed
from the mid-1980s to the mid-1990s. This data set included Rollover
Test Device (RTD) tests, 208 Dolly tests, guardrail tests and pole
tests.\81\ A film analysis of dummy motion within the vehicles showed
that, excluding a pole impact test, occupant contact with the window
opening and surrounding area first occurred between 0.16 and 0.88
seconds after the event began.\82\ We note, however, that the majority
of these dummies were belted, which means they would be most
representative of potential partial ejections. In addition, where the
time of window breaking is known, most of these first contacts occurred
prior to the window breaking due to roof contact.
---------------------------------------------------------------------------

\81\ These tests were done as part of a research program
evaluating full scale dynamic rollover test methods, occupant
kinematics, and vehicle responses. The RTD tests were similar to the
208 Dolly test except that the vehicle was initially 4 feet off of
the ground instead of 9 inches, and hydraulic cylinders were used to
push the vehicle from the cart and produce an initial roll rate. The
guardrail tests used a guardrail as a ramp to initiate a vehicle
roll. The pole tests rolled a vehicle into a pole. Twenty-four of
these were RTD tests on passenger cars, pickups and vans (the RTD
testing was not geared towards ejection testing since all of the
test dummies were belted), and four were 208 Dolly tests on Ford
Explorers. The test films are available at the National Crash
Analysis Center (NCAC) at George Washington University
(www.ncac.gwu.edu).
\82\ ``Evaluation of Full Vehicle Rollover Films,'' 2008, Docket
NHTSA-2006-26467.

Table 31--NHTSA Full Vehicle Rollover Testing Film Analysis
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tilt Vehicle
Test Make Model MY Test type angle Roll axis speed (km/ \1/4\ Total time
(deg.) (deg.) h) Turns (sec)
--------------------------------------------------------------------------------------------------------------------------------------------------------
878............... Honda............... Accord.............. 84 RTD................. 41 45 33.8 2 1.29
888............... Chevrolet........... Celebrity........... 82 RTD................. 41 45 37.0 4 3.58
920............... Dodge............... Omni................ 79 RTD................. 41 45 37.0 2 0.96
939............... Mercury............. Zephyr.............. 82 RTD................. 41 60 37.0 2 2.08
1255.............. Ford................ Bronco.............. 88 RTD................. 30 45 37.0 2 1.17
1266.............. Dodge............... Caravan............. 88 RTD................. 30 45 48.3 1 0.50
1267.............. Chevrolet........... Pickup.............. 88 RTD................. 30 45 48.3 4 2.58
1274.............. Nissan.............. Pickup.............. 88 RTD................. 30 45 48.3 6 3.76
1289.............. Nissan.............. Pickup.............. 89 RTD................. 30 45 48.3 2 0.83
1391.............. Dodge............... Caravan............. 89 RTD................. 30 45 48.3 8 5.08
1392.............. Ford................ Bronco.............. 89 RTD................. 30 0 48.3 8 3.60
1393.............. Nissan.............. Pickup.............. 89 RTD................. 30 0 48.3 4 2.35
1394.............. Nissan.............. Pickup.............. 89 RTD................. 30 0 48.3 4 1.33
1395.............. Pontiac............. Grand Am............ 89 RTD................. 30 0 48.3 2 1.54
1471.............. Dodge............... Colt................ 89 RTD................. 30 90 48.3 2 0.99
1520.............. Ford................ Ranger.............. 88 RTD................. 30 0 48.3 2 0.75
1521.............. Dodge............... Ram................. 88 RTD................. 30 0 48.3 4 1.42
1530.............. Dodge............... Caravan............. 88 Guardrail........... NA NA 96.6 1 N/A
1531.............. Nissan.............. Pickup.............. 88 Guardrail........... NA NA 96.6 4 N/A
1546.............. Plymouth............ Reliant............. 81 RTD................. 41 45 33.8 6 3.00
1851.............. Volvo............... 240................. 91 RTD................. 30 0 48.3 6 2.50
1852.............. Volvo............... 740................. 91 RTD................. 30 0 48.3 8 3.00
1925.............. Nissan.............. Pickup.............. 90 RTD................. 30 0 48.3 8 3.04
1929.............. Nissan.............. Pickup.............. 90 RTD................. 30 0 48.3 6 2.25
2141.............. Nissan.............. Pickup.............. 90 RTD................. 30 0 48.3 8 4.25
2270.............. Nissan.............. Pickup.............. 89 RTD................. 30 0 48.3 8 3.50
2514.............. Ford................ Explorer............ 94 208................. 23 0 48.3 11 5.50
2553.............. Ford................ Explorer............ 93 208................. 23 0 48.3 10 N/A
3012.............. Ford................ Explorer............ 94 208................. 23 0 48.3 11 N/A
3635.............. Ford................ Explorer............ 94 208................. 23 0 48.3 12 5.17
--------------------------------------------------------------------------------------------------------------------------------------------------------
Analysis of 5+ \1/4\ turn Tests:
Average.......................................................................................................... 47.2 8.3 3.7
Maximum.......................................................................................................... 96.6 12 5.5
Average +2 standard deviations................................................................................... 55.2 12.3 5.8
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 3251]]

The agency proposed that the ejection mitigation countermeasure be
first tested at 1.5 seconds after deployment of the ejection
countermeasure. As indicated earlier in this preamble, slightly less
than half of the complete ejection fatalities occur when the vehicle
rolls up to 5 quarter-turns.\83\ As shown in Table 30, restricting the
analysis to the tests with 5+ quarter-turns, the average amount of time
to complete 1 full vehicle revolution (4 quarter-turns) was 1.62
seconds with a standard deviation of 0.31 seconds. Thus, the 1.5 second
represented a period of time in which one full vehicle revolution
occurs in a high energy rollover event. (We also noted that at 1.5
seconds into the rollover, roof contact would likely have occurred,
leading to window breaking. Thus, as discussed later in this preamble,
we proposed and adopt a requirement that if advanced glazing is
present, it is pre-broken prior to this test.)
---------------------------------------------------------------------------

\83\ The 50 percent point in the cumulative distribution occurs
between 5 and 6 quarter turns.
---------------------------------------------------------------------------

Additional rationale came from data obtained from the advanced
glazing program (see Table 32, infra).\84\ In that program, NHTSA
tested vehicles on the DRF with 5th percentile adult female and 50th
percentile adult male test dummies (near and far side).\85\ Analysis of
dummy head impacts with the glazing in the window opening showed that
for the 5th percentile female far side occupant, the time to glazing
impact after the DRF began rotating was between 1.3 and 1.8 seconds,
which was in the range of two to three quarter-turns of rotation.
Additional analysis of the DRF testing is presented later in this
preamble.
---------------------------------------------------------------------------

\84\ Duffy, S., ``Test Procedure for Evaluating Ejection
Mitigation Systems,'' 2002 SAE Government/Industry Meeting.
\85\ For this set of tests, the ``near'' and ``far'' side dummy
configurations represent the trailing occupants in a rollover. The
near side occupant simply means that they were initially placed near
the door at what would have been behind the steering wheel, if the
steering wheel were present. The far side occupant was moved to an
initial position which was towards the centerline of the vehicle.
This position could be thought of as a position that a trailing
occupant could slide to as a yawed vehicle decelerates in the
lateral direction, prior to rollover initiation.

Table 32--DRF Testing Results
------------------------------------------------------------------------
Far side Far side
impact impact
Dummy time [frac14]
(sec.) turns
------------------------------------------------------------------------
5th Female and 50th Male............................ 1.3-1.8 2-3
------------------------------------------------------------------------

The agency also proposed that ejection mitigation countermeasures
be tested towards the end of a rollover. Data indicated that occupants
could impact the window opening as late as 6 seconds after initiation
of a rollover involving 5+ quarter-turns. The last three rows of Table
31, supra, show the average and maximum number of quarter-turns and the
total time of rollovers involving 5+ quarter-turns.\86\ This set of
data contains 14 such tests. The average and maximum number of quarter-
turns are 8.3 and 12, respectively. The average plus two standard
deviations is 12.3 quarter-turns. Thus, 12.3 quarter-turns is the 98th
percentile value for this subset of data. The average and maximum times
to complete the entire rollover event were 3.7 and 5.5 seconds,
respectively. The 98th percentile value was 5.8 seconds, which is not
much different than the maximum time for the entire data set, which was
5.5 seconds.
---------------------------------------------------------------------------

\86\ As mentioned earlier, just less than half of the complete
ejection fatalities occur when the vehicle rolls up to 5 quarter-
turns.
---------------------------------------------------------------------------

Other information we considered also supported a 6-second impact
time. The 1988-2005 NASS-CDS showed that rollovers with eleven quarter-
turns account for about 90 percent of rollovers with fatal complete
ejection, i.e., 10 percent of rollovers with fatal complete ejections
have more than eleven quarter-turns. The data set provided in Table 31,
supra, showed the vehicle that rolled eleven quarter-turns had the
longest roll time (5.5 seconds) in the 208 Dolly test.\87\
---------------------------------------------------------------------------

\87\ The agency explained in the NPRM that this does not mean
that rollover crashes with eleven quarter-turns only take 5-6
seconds. Five to six seconds may be a conservative assumption for
this many quarter-turns for some types of rollover events. The 208
Dolly test has a very quick rollover initiation (high initial roll
rate); the beginning of the rollover is well defined. This test only
represents about 1% of field crashes. Viano, supra. The vast
majority of field cases are soil and curb trip crashes. Soil trips
involve high lateral deceleration in combination with low initial
roll rates. Ideally, the curtain air bag should deploy in this early
phase when the roll rate is still low but the occupant is moving
towards the window due to the lateral deceleration. The rollover has
a slow initiation, leading to a need for longer inflation.
Therefore, some rollover crashes with less than eleven quarter-turns
may have 5-6 second roll times.
---------------------------------------------------------------------------

A factor that the agency considered in determining the time delay
for the lower speed impact was the practicability of curtains staying
inflated for this length of time. Ford stated that its ``Safety
Canopy'' system stays inflated for six seconds.\88\ GM reportedly
stated that its side curtain air bags designed for rollover protection
maintain 80 percent inflation pressure for 5 seconds.\89\ It appeared
that a requirement that side curtain air bags must contain the headform
when tested six seconds after deployment was realistic and attainable.
---------------------------------------------------------------------------

\88\ http://media.ford.com/article_display.cfm?article_id=6447
(Last accessed October 6, 2010.)
\89\ ``Who Benefits From Side and Head Airbags?'' (http://www.edmunds.com/ownership/safety/articles/105563/article.html).
---------------------------------------------------------------------------

ii. Comments on Time Delay
The Alliance and Honda suggested different time delays than that
proposed by the NPRM. Both commenters referenced NASS CDS data of the
distribution of rollovers by the number of quarter-turns. The 1997-2007
data were presented in the PRIA. These data show that for all
rollovers, not just those with ejections, the majority of the rollover
population was at 1 to 2 quarter-turns. These commenters stated that
since these data show that the cumulative percentage of rollovers is 90
percent at 5 quarter-turns, and 96 percent at 7 quarter-turns, the time
delay for the late impact should be greatly reduced. They correlated
these 5 and 7 quarter-turn values with the agency's full vehicle
rollover test data to arrive at their requested time delays of 3.4
seconds (Alliance) and 3 seconds (Honda).
Guardian requested that NHTSA conduct an analysis of what
protection exists under conditions when an air bag does not deploy. The
commenter seemed to be concerned that the 1.5 second impact test was
not being performed early enough to address ejections in side impacts.
It suggested that this may lead to air bag entrapment of partially
ejected occupants and that advanced glazing can prevent this.
Advocates was concerned about the test procedure impacting the
ejection countermeasure at two discrete times. The commenter believed
that the compliance test only takes a ``snapshot of air curtain and
sensor performance at two brief intervals over the several seconds
during which an air curtain is supposed to provide sustained inflation
and prevent excursion beyond 4 inches. For example, no sustained
inflation is tested between the 1.5 and 6 second tests, when excursion
could exceed the 4 inch maximum required by the proposed standard.''
\90\ Advocates stated that a compliant system still may allow
excursions beyond 100 mm at other points during the rollover,
especially those longer than 6 seconds.
---------------------------------------------------------------------------

\90\ NHTSA-2009-0183-0022, p. 12.
---------------------------------------------------------------------------

iii. Agency Response
The agency declines to increase or decrease the time delay for the
1.5 second and 6 second impacts. We also

[[Page 3252]]

have decided against adding a third impact test at a later time or
performing any testing at time delays between 1.5 and 6 seconds or at a
time representative of a side impact.
In developing the time delays in the standard, NHTSA recognized
that the majority of occupants exposed to rollover crashes are in
vehicles that roll two quarter-turns or less. However, we recognized
that the distribution of ejected occupants who are seriously injured
(maximum abbreviated injury scale (MAIS) 3+) or killed is skewed
towards rollovers with higher degrees of rotation. According to NASS
Crashworthiness Data System (CDS) data of occupants exposed to a
rollover crash from 2000 to 2009, half of all fatal complete ejections
occurred in crashes with six or more quarter-turns. We wanted to
address the fatally and seriously injured populations.
This information was illustrated in the NPRM by the Figure 11
below. The updated target population for this final rule shows that the
vast majority of the ejection fatalities (69 percent = 3,067/4,447) are
complete ejections. This final rule is designed to mitigate ejections
from rollover crashes that cause the most harm (those that result in
complete ejection). By doing so, the countermeasures installed pursuant
to this rule will reduce fatalities and injuries resulting from severe
rollovers. Countermeasures installed to mitigate ejections in crashes
with higher degrees of rotation will help occupants involved in those
crashes as well as occupants exposed to rollovers of less severity. The
inverse would not be true.
[GRAPHIC] [TIFF OMITTED] TR19JA11.012

The Alliance indicated that a rollover time representing the
cumulative percentage of at least 90 to 96 percent of rollovers is
appropriate. Using this range of values and applying it to rollovers
resulting in fatal complete ejections, the resulting number of quarter-
turns is in the range of 10 to 12 quarter-turns for the 1997-2005 NASS
CDS data and approximately 8 to 10 quarter-turns for the more recent
2000-2009 NASS CDS data. The Alliance showed a regression line through
the quarter-turns versus rollover times for the agency's full vehicle
rollover test data (Table 11 in the NPRM). The commenter did not show
the equation for the line. We derived the equation as y = 0.48x, where
y = rollover time in seconds and x = number of quarter-turns. Using
this equation, the range of 8 to 12 quarter-turns gives the result of
3.8 to 5.8 seconds. Thus the upper end of this range is consistent with
the time of the low speed impact proposed in the NPRM \91\ and adopted
by this final rule. (As noted in the NPRM, the 6-second value may be a
conservative assumption for the corresponding number of quarter-turns
seen in FMVSS No. 208 Dolly testing. Some rollover crashes with less
than eleven quarter-turns may have 5 to 6 second roll times.)
---------------------------------------------------------------------------

\91\ 74 FR 63196.
---------------------------------------------------------------------------

Based on the analysis above, the agency declines to reduce the time
delay for the second impact to less than 6 seconds, as reducing the
time delay would not be consistent with our stated goal of protecting a
``far-reaching population of people in real world crashes.'' \92\
---------------------------------------------------------------------------

\92\ 74 FR 63182.
---------------------------------------------------------------------------

Guardian's request that NHTSA conduct an analysis of what
protection exists under conditions when an air bag does not deploy
appears to relate to a concern with the 1.5 second impact test not
being performed early enough to address ejections in side impacts. In a
side crash, the occupant will interact with the side of the vehicle
within a few tenths of a second. In response to Guardian, our
experience with vehicles with side curtains that deploy in rollovers is
that manufacturers design them to deploy in side impacts as well. These
side curtain must provide head and thorax protection in an oblique pole
test, pursuant to FMVSS No. 214, and

[[Page 3253]]

must be designed to deploy and be in position in a matter of
milliseconds. In recent testing of side impact air curtains to FMVSS
No. 214 and New Car Assessment Program protocols, we have not found
non-deployment of or entrapment by side impact curtain air bag
entrapment to be a problem.
Advocates requested that we add a third impact test with a delay
time greater than 6 seconds. We decline to do so. In the NASS CDS
database, combining MAIS 3+ injuries and fatalities results in only
about 0.4 percent of ejected occupants are in rollovers with more than
16 quarter-turns (see Figure 11). Using the linear regression from the
208 Dolly testing (y = 0.48x) would result in a duration of 7.7 seconds
at 16\1/4\-turns. Hence, there is a diminishing return in terms of the
population of ejection rollovers covered by increasing the delay time
for the impact test beyond 6 seconds. In addition, there will be costs
to redesigning ejection mitigation systems to accommodate a third
impact after 6 seconds, assuming the design is practicable; NHTSA
cannot conclude the redesign will be cost-effective. With regard to
Advocates' concern that ``no sustained inflation is tested between the
1.5 and 6 second tests, when excursion could exceed the 4 inch maximum
required by the proposed standard,'' we will not add a test to assess
the countermeasure between 1.5 seconds and 6 seconds. We know of no
ejection mitigation side curtain system that deflates and inflates
itself midway through the test.
Finally, we note that the regulatory text (S5.5(a)) has been
clarified to indicate that the time delay applies to deployable
countermeasures. For a daylight opening with a non-deployable
countermeasure, e.g., fixed advanced glazing, there is no time
dependence for the impact. The impactor can be propelled at any time.
2. NPRM on Speed at Which the Headform Impacts the Countermeasure
i. NPRM on Impact Speed
As discussed above, our examination of field crash data has led to
the conclusion that the impact test should have both a relatively high
speed impact shortly after countermeasure deployment and a lower speed
impact late in the deployment.
The first test in the NPRM was at a 24 km/h impact velocity, 1.5
seconds after countermeasure deployment. Field data show that crashes
with 6 or more quarter-turns result in the majority of complete
ejection fatalities. The 1.5 second time delay for the high speed
impact corresponds well to the film analysis of vehicles that roll 5 or
more quarter-turns in FMVSS No. 208 Dolly tests, for the amount of time
it takes for one complete vehicle revolution. The NPRM reported that
laboratory testing using the DRF showed that at around 1.5 seconds, a
far side occupant could strike the window opening at nearly 30 km/
h.\93\ MADYMO computer simulation of three actual rollover crashes
predicted that the maximum head speed into the window openings was 22
km/h.\94\ Additional justification for the 24 km/h impact speed was
found in side impact field data. NASS CDS shows that 35% of occupants
completely ejected through the side windows in side impact are exposed
to impacts with a [Delta]V greater than 24 km/h. It was also noted that
FMVSS No. 201 also uses a 24 km/h impact speed for the upper interior
tests.
---------------------------------------------------------------------------

\93\ The agency has reassessed the video data of the DRF testing
and calculated lower speeds than originally reported. This is
covered in more detail later in this preamble.
\94\ 74 FR at 63195
---------------------------------------------------------------------------

The second test in the NPRM has a 6 second delay and a 16 km/h
impact speed. Agency film analysis found that the maximum roll time was
5.5 seconds for a vehicle that rolled 12 quarter-turns. A separate film
analysis of a much smaller data set found a maximum head speed into the
window opening of 17 km/h.\95\ Modeling of three rollover crashes
showed a maximum torso impact speed of 16 km/h.
---------------------------------------------------------------------------

\95\ 74 FR at 63197
---------------------------------------------------------------------------

ii. Comments on Impact Speed
The Alliance, AIAM, and a number of vehicle manufacturers commented
on the impact speed. All of these commenters requested that NHTSA
reduce the impact speed of the higher speed 24 km/h test.\96\ The
requested levels of reduction varied. The commenters did not agree
there was a need for a 24 km/h speed, and expressed concern about the
potential adverse effects and unintended consequences of not reducing
the impact speed, particularly as they relate to side impact
protection, protection of out-of-position occupants, and performance in
NCAP testing.
---------------------------------------------------------------------------

\96\ The 24 km/h test imparts about 400 joules of energy, while
the 16 km/h test imparts approximately 178 J.
---------------------------------------------------------------------------

The Alliance requested that the 24 km/h test be reduced to 16 km/h.
As discussed in the previous section, the Alliance suggested that a 16
km/h test be the only test and be performed at 3.4 seconds after
curtain deployment. The Alliance stated that GM \97\ and Ford \98\
conducted extensive research in this area and have both concluded that
the maximum impact energies in the range of 180 to 200 joules (J) were
appropriate to address the vast majority of real world rollover events.
The commenter stated that this energy level was also validated by the
agency's own sled test research (see 74 FR at 63192) simulating both
rollover and side impact events, which both produced kinetic energies
in the range of 180 to 200 J.
---------------------------------------------------------------------------

\97\ O'Brian-Mitchell, Bridget M., Lange, Robert C., ``Ejection
Mitigation in Rollover Events--Component Test Development,'' SAE
2007-01-0374.
\98\ Docket No. NHTSA-2006-26467-0002.
---------------------------------------------------------------------------

Referring to the GM research, the Alliance stated the 16.2 km/h
impact speed was derived from analysis of a series of rollover sensor
development tests, in which data was collected in an attempt to
quantify the kinetic energy associated with an occupant loading the
roof rail airbag system. The 52 tests included both belted and unbelted
test dummies. The Alliance stated that in all cases, the kinetic energy
value associated with the dummy's interaction with the roof rail airbag
surrogate (referred to in the study as a window membrane) was less than
180 J.
The Alliance stated that another very influential study that
solidified GM's decision to test at 16.2 km/h was the NHTSA sled
testing referenced in the NPRM. The sled tests were conducted to
determine the effect lower body loading would have on the combined head
and upper torso effective mass. The Alliance stated, ``The sled testing
representing the rollover condition was conducted at 16 km/h, while the
side impact simulation was run at 24 km/h. Once the effective mass was
determined, both impact conditions produced a kinetic energy between
180-200 J.'' The commenter suggested that this validates the approach
GM had adopted in simulating the occupant kinetic energy in a rollover
with an 18 kg impactor at a speed of 16.2 km/h, and shows that the
kinetic energy associated with this subsystem test would be applicable
to side impact as well.''
The Alliance indicated that since they agree with the impactor mass
of 18 kg, the appropriated impact ``is derived from the equation for
linear kinetic energy (KE = 1/2mv\2\; m = mass and v = speed). The
Alliance's recommended impact speed is calculated by substituting m =
18 kg and KE = 178 Joules, resulting in a speed of 16 km/h (4.44 m/
s).''
To emphasize their belief that the 24 km/h test is too severe, both
the

[[Page 3254]]

Alliance and Volvo referred to the agency's analysis in the PRIA,\99\
which indicated that a 24 km/h speed (for occupant to ejection
countermeasure) corresponds to a pre-crash velocity of 133 km/h (83
mph). They indicated that such a pre-crash speed is too rare an
occurrence to be reflected in the final rule.
---------------------------------------------------------------------------

\99\ NHTSA-2009-0183-0002, p. VIII 18.
---------------------------------------------------------------------------

AIAM and VW recommended that the agency first determine the
appropriate impact energy and then establish the impactor mass and
velocity based on this. AIAM was concerned that impact speeds projected
by the agency are typically associated with masses smaller than the
proposed 18 kg impactor. VW recommended an impact energy of 180 J,
which would correspond to a 18 kg impactor traveling at 16 km/h. VW
provided a table of its modeling results from a linear impactor into an
air bag (Table 3 in VW comments) showing that impact excursion is
primarily a function of the initial kinetic energy of the impactor, as
opposed to mass and impact speed.
Honda requested that the agency focus on a maximum energy level of
200 J. The commenter referred to the analysis of GM showing that the
effective mass of an occupant's initial contact with a side window in a
full vehicle rollover test indicates a constant energy of less than 200
J. Honda stated that its own testing showed that the estimated peak
head velocity and effective mass, when tested in accordance with FMVSS
No. 208, were also less than 200 J. Honda stated that an upper
threshold of 200 J would account for the energy imparted on the side
window by a belted occupant.
Nissan commented that its preliminary study of impact energy
associated with occupant ejection showed values below 207 J. Based on
this and concerns of safety tradeoffs that could exist between FMVSS
No. 214, it recommended that the final rule limit the higher speed
impact to 20 km/h, corresponding to an energy of approximately 280 J.
Batzer and Ziejewski stated that based on the ``testing and
analysis that we have seen and performed, NHTSA's 15 mph [24.1 km/h]
impact velocity choice is inappropriately high.'' They stated that a
``two impacts against the upper half of the glazing'' at 16.1 km/h
would be an adequate requirement. They continue that ``in side impacts,
although a large relative occupant-to-glazing nominal velocity may
result, the door actually takes the brunt of the energy and momentum.''
Air bag supplier Takata expressed support for the proposed 24 km/h
test, stating: ``We believe it is important to test all the locations
at the high energy level to ensure structural integrity of the
countermeasure device.'' \100\ The commenter also informed NHTSA that a
24 km/h test speed requirement would be practicable. (NHTSA-2006-26467-
0019, infra.)
---------------------------------------------------------------------------

\100\ NHTSA-2009-0183-0015, p. 2.
---------------------------------------------------------------------------

iii. Agency Response
As explained in this section, NHTSA has evaluated the comments
asking us to base a decision on the impact speed on the findings of a
GM study and a Ford study. After reviewing the findings of the studies,
we do not find those GM and Ford data sufficiently informative.
However, we have carefully considered the comments recommending
that the agency reassess the impactor speed proposed on the basis of
what should be the impact energy imparted to the ejection mitigation
countermeasure, given an impactor mass of 18 kg. We agree that,
particularly in the case of a curtain air bag countermeasure, the
energy imparted by the linear impactor is a critical factor in the
determination of the stringency of the performance requirement as
compared to only considering the impact speeds or impactor mass. We
acknowledge that some data available to the agency, e.g., DRF testing,
vehicle interior video of FMVSS No. 208 Dolly tests, and MADYMO
simulations, only allow for an assessment of impact speed. Estimates of
energy from these data require assumptions to be made about effective
mass values or further computational modeling.
Accordingly, we have reanalyzed sled test data from the advanced
glazing program to measure the energy the mid-size adult male dummy
imparted to the countermeasure. We analyzed the data from a 24.1 km/h
(15 mph) test meant to be more indicative of a side impact condition
and a 16.1 km/h (10 mph) test meant to be more indicative of a rollover
condition. For the 24.1 km/h (side impact) test, we determined the
energy imparted to the window opening was 290 J. For the 16 km/h
(rollover) condition, the energy on the window opening was calculated
to be 220 J. These were the only laboratory test data available to the
agency for direct analysis of impact energy. For the limited conditions
tested, the results were not at the estimated energy levels in the 400
J range, equivalent to the impactor energy when traveling at the 24 km/
h speed considered by the NPRM.
After reviewing the comments, we also reanalyzed DRF data used in
the NPRM and found that the original transcription of the film speed
used to determine impact speed was not done properly. We stated in the
NPRM that video analysis of dummy head impact velocities with the
glazing showed that for the 5th percentile female far side occupant,
the peak impact speed was 31 km/h. After reanalyzing the data for this
final rule, we determined that the peak head and shoulder impact speeds
were approximately half that reported in the NPRM.
We have determined that, based on a thorough analysis of all
available information, including the reanalyzed sled testing used by
the agency in the advanced glazing program and the DRF data discussed
in the NPRM, the test speed for the 1.5 second test adopted by this
final rule should be 20 km/h, rather than the proposed 24 km/h. A 20
km/h test would better represent the energies to which the ejection
countermeasure will be exposed to in the field, particularly in
rollovers.
A. Analysis of GM Study on Impact Energy
Several commenters referred to a GM study in which GM determined
the effective mass and impact energy on a membrane covering the first
row window. The agency had analyzed this study and provided a review of
it in the NPRM and the Technical Analysis supporting the NPRM,
regarding the basis for the impactor mass determination of 18 kg. A
brief description of the study is provided below.
GM conducted a study to develop rollover sensors, using 52 full
vehicle rollover tests. It also attempted to assess the effective mass
and impact energy on the front window area by belted and unbelted test
dummies. Forty-six percent of the tests were less than a quarter-turn,
27 percent were one quarter-turn and 27 percent were two quarter-turns.
In the tests, the two front seats were occupied by 50th percentile
adult male Hybrid III dummies. Half of the tests were with belted
dummies and half were unbelted. The belt status versus number of
quarter-turns was not reported by the authors.
The method used to estimate the effective mass required the
calculation of the resultant loading on the dummy head by the window
membrane using head acceleration, neck loading and a dummy head mass
assumed to be 4.204

[[Page 3255]]

kg.\101\ The effective mass was then determined by using this head
contact force along with the resultant head and chest accelerations.
Energy levels were calculated by using effective mass and peak head
velocity. As noted by various commenters to the NPRM for today's final
rule, the estimated effective mass for most belted tests was about 5 kg
and all were less than 10 kg. The effective mass for the unbelted
occupants ranged from 5 to 85 kg. The authors reported that the highest
energy level was 182.3 Nm.
---------------------------------------------------------------------------

\101\ Although the membrane had force measurement
instrumentation at each corner, these measurements were not used in
the analysis due to a ``data integrity issue.''
---------------------------------------------------------------------------

We believe that the GM data set has little relevance to this
rulemaking with respect to the loading of the side window openings in
crashes that cause the most ejection harm. With regard to the energy
values derived from this study, it is important to identify several key
limitations. First, the study was done as a development tool for
sensors, not as a means of determining the range of potential occupant
loading/energy on ejection countermeasures in relatively severe
rollover crashes. As such, vehicle dynamics that show a vehicle on the
threshold of rolling or not rolling is of great interest in sensor
development. From the distribution of quarter-turns in these tests, the
focus of the study was on the minimum thresholds for sensor deployment,
i.e., rollovers of two or fewer quarter-turns. In contrast, to cover 90
percent of all rollovers inducing serious injury and fatal ejections, a
study of rollovers involving 8 or more quarter-turns is more
appropriate. Regarding rollovers causing complete fatal ejections, a
cumulative population of 90 percent of these crashes would necessitate
an analysis of crashes involving 9 or more quarter-turns. The force
imparted on the side window openings in these types of crashes is
substantially greater than that discerned by GM in this study.
Second, although the authors state that the highest energy level
estimated was below 182.3 J, they subsequently report a case where they
estimate that the trailing side occupant alone imparts 243 J to the
membrane. We thus believe it is more accurate to state that the highest
energy calculated in this set of tests was at least 243 J. It would
also be very important to know if the leading occupant was applying
load at the same time as the trailing occupant, perhaps adding to the
243 J value. Nonetheless, we note that a single unbelted leading
occupant was estimated to have more than 100 J of energy. If both a
trailing and leading occupant were to load the window area
simultaneously, the total energy would be 343 J. Restricting ourselves
to consideration of the 243 J value, we can correlate this energy to
the ejection mitigation test procedure by assuming an impactor mass of
18 kg. The corresponding impact velocity would be 18.7 km/h.
Third, the methodology and data presented in the GM study seem to
indicate that only membrane loading from the dummy heads was estimated.
The agency's sled testing indicated that more load is transmitted
through the shoulder than the head, and even more load is imparted when
both the head and shoulder impart loads at the same time. We do not
believe only head loading should be considered when evaluating the load
impacted by an occupant on the ejection mitigation countermeasure, even
for unbelted dummies, as this may have contributed to lower energy
estimates.
B. Analysis of Ford Study on Impact Energy
Several comments from vehicle manufacturers made reference to
modeling Ford performed in which Ford estimated the effective mass and
impact energy that occupants would impart to the first row window in a
rollover. This information was originally presented to NHTSA at a
February 7, 2007 meeting with the agency.\102\ Ford conducted computer
modeling on three vehicle models, with belted and unbelted 50th
percentile adult male and 5th percentile adult female Hybrid III
dummies. This was originally done ``to determine the appropriate energy
for a headform impact test procedure for Safety Canopy development.''
The reported effective mass range was about 5 to 35 kg (average of 14
kg) for belted occupants and 5 to 50 kg (average of 24 kg) for unbelted
occupants. The reported peak energy values were similar for belted and
unbelted occupants, at about 180 J. These maximum values appeared to
occur early in the simulations (< 200 ms).
---------------------------------------------------------------------------

\102\ Docket No. NHTSA-2006-26467-0002.
---------------------------------------------------------------------------

Ford indicated that they modeled curb trip and SAE J2114--Dolly
Rollover Recommended Test Procedure (Dolly) tests. The speeds, vehicle
roll rates, and quarter-turns were not reported.\103\ As such, it is
very difficult for us to assess the severity of the rollovers that were
simulated. As was the case in our analysis of the GM study, rollovers
that only produce a few quarter-turns are not representative of the
ejection-causing crashes that we are attempting to cover by this
standard.
---------------------------------------------------------------------------

\103\ The SAE J2114 test uses the same test configuration as the
208 Dolly test. However, the 208 Dolly test is performed at a speed
of 48 km/h. SAE J2114 does not have a recommended speed.
---------------------------------------------------------------------------

The majority of the data was reported before 600 ms into the event.
This is probably less than 2 quarter-turns into the event, depending on
how Ford determined time zero. It is unclear if Ford only modeled part
of the event. For vehicles that undergo many more quarter-turns, there
may be impacts with the window area that were not captured by Ford's
modeling only the first few quarter-turns.
The agency analyzed the Ford study and did not find the results to
be persuasive. The fact that a set of simulations result in energy
estimates below 180 J is of limited use to the agency's determination
of an impact speed/energy that will protect a far-reaching population
of occupants.
C. Reanalysis of Agency Data From NHTSA Sled Testing
Several commenters to the NPRM stated that the agency's own sled
testing indicated that the appropriate energy of the impact should be
below 200 J. They are referring to sled testing that was performed in
1993 as a follow-up to dummy pendulum impacts.\104\ The sled tests were
conducted to determine the appropriate mass of a linear impactor to be
used in the testing of advanced glazing (the headform impactor).\105\
---------------------------------------------------------------------------

\104\ ``Ejection Mitigation Using Advanced Glazing: A Status
Report,'' November 1995, Docket No. NHTSA-1996-1782-3. Pg. 7-10.
\105\ These have been entered as test Nos. 10282--10287 in the
NHTSA Biomechanics Test Database. They are accessible at http://www-nrd.nhtsa.dot.gov/database/aspx/biodb/querytesttable.aspx.
---------------------------------------------------------------------------

These tests were described as incorporating a ``side impact''
condition and a ``rollover'' condition, although they were both side
impact sled tests. For the test designed to be more representative of a
side impact condition, the target impact speed was 24.1 km/h and the
dummy (a 50th percentile adult male BioSID) was positioned was seated
upright. In the rollover condition, the target impact speed was
described as 16.1 km/h \106\ and the dummy was positioned leaning
towards the door such that its head and torso would contact the
simulated glazing (foam) at about the same time. This leaning position
was intended to be more representative of an occupant's attitude in a
rollover. In both conditions the foam was positioned such that head and
shoulder contact with the foam was achieved at similar times.
---------------------------------------------------------------------------

\106\ Although we refer to this as the 16.1 km/h test, we found
that the actual test speed for the test we analyzed in detail was
15.2 km/h.

---------------------------------------------------------------------------

[[Page 3256]]

It should be understood that the testing was not designed to
directly measure the energy the countermeasure must absorb in order to
prevent an occupant ejection. Rather, this set of tests was a follow-up
to dummy pendulum impacts used to determine the appropriate mass of a
linear impactor used to test advanced glazing. (If energy assessment
had been the goal, a means of measuring displacement of the loaded
reaction surface (foam or surface behind it) could have been
undertaken. As it is, no direct measurement of the displacement of the
loaded surface was made.)
In response to the comments to the NPRM, we reanalyzed the sled
test data in an effort to estimate the energy the incoming dummy
imparted to the foam. This new analysis is discussed in detail in the
technical report accompanying this final rule. Briefly stated, for the
24.1 km/h (side impact) test, we determined that the energy imparted to
the window opening was approximately 290 J (rounded up from 287 J). We
believe this energy likely represents a minimum value for this test
configuration.\107\ From this energy value we estimated the effective
mass of the test to be 13 kg. As described below, the energy and
effective mass estimates for the 16.1 km/h (rollover) test were more
complex. However, based on this analysis we estimate the energy of that
impact to be 200 J and the effective mass to be 22 kg. However, this
test was actually performed at approximately 15.5 km/h. If it had been
correctly performed at 16.1 km/h (10 mph), the energy would have been
220 J. (Note that these values do not support the commenters to the
NPRM that stated that the agency's sled testing indicated that the
appropriate energy of the impact should be below 200 J. These sled
tests alone provide a range of energies between 220 to 290 J that,
assuming an impactor mass of 18 kg, correspond to a range of impact
velocities of 18.5 to 20.6 km/h.)
---------------------------------------------------------------------------

\107\ We say ``minimum'' because by the nature of impact into
foam, there were energy losses that would not be reflected in the
estimated impact energy.
---------------------------------------------------------------------------

24 Km/h Test
The process of reanalysis started with the 24.1 km/h upright (side
impact) tests. The energy into the foam padding was determined by
assessing the ``work'' done on the dummy, i.e., the integral of the
lateral force versus lateral displacement on the dummy. The lateral
force on the dummy was assumed to be the force measured by the load
cells behind the foam (the foam was a surrogate for the window
countermeasure) for the head and shoulder load cells. Equation (1)
represents the energy of the head into the foam. A similar equation can
be written for the shoulder.
[GRAPHIC] [TIFF OMITTED] TR19JA11.013

Where:

Fh = Force measured at head foam pad, assumed to be
lateral force on dummy head.
yh/s = y (lateral) displacement of the dummy head
relative to the sled.
T = Time

The analysis is set forth in detail in the technical report. We
determined that, because in the 24.1 km/h test the dummy was initially
positioned upright (i.e., the midsagittal plane aligned with a vertical
axis), the head and shoulders of the dummy contacted the foam pads at
about the same time. This resulted in the dummy maintaining its upright
position during force application through the foam. We assumed there
was no significant rigid body rotation; examination of the test video
confirmed this assumption. This assumption allowed the use of the
measured head c.g. (center of gravity) acceleration to be integrated
once for velocity and twice for displacement. In the case of the torso/
shoulder loading, the accelerometer at the first thoracic vertebra (T1)
was used.
Three different types of foam padding were used in the original
tests.\108\ In order of increasing stiffness, the foams were:
Polystyrene, Arsan and Ethafoam LC 200. Table 33 shows the estimated
impact energy and the measured maximum force at the head and shoulder
on the Ethafoam pads, as well as the maximum combined values. The
combined maximum energy value was 287 J. We believe it is appropriate
to consider the total energy value that combines the maximum head and
shoulder components in that this would represent the total amount of
energy that the countermeasure must absorb. The same type of energy
estimate was made for the tests with Arsan and polystyrene using eq. 1.
The energy estimates were 282 J and 252 J for Arsan and polystyrene,
respectively. We expect the less stiff Arsan and polystyrene to result
in lower energy estimates.
---------------------------------------------------------------------------

\108\ We recognize that for all of the tests there was energy
loss into the foam, i.e., the foam absorbed the energy of the impact
without returning it to the dummy. The foam cells were heated,
deformed beyond their elastic limit and/or were destroyed. Thus, the
loads imparted to the dummy were lower than would be the case if
foam were not present. Since energy was derived from the load cell
force measured behind the foam pad and the displacement of the head
(or shoulder) in the direction of force, the lower force imparted to
the dummy resulted in a lower calculated energy. This is to say, the
estimate of the work/energy needed for an ejection countermeasure
was likely an underestimate. The extent of the underestimation is
not known.

Table 33--Energy (Eq. 1) and Force on the Ethafoam Padding in the 24.1
km/h Sled Test
------------------------------------------------------------------------
Maximum Maximum
energy (J) force (N)
------------------------------------------------------------------------
Head.......................................... 97.1 2,569
Shoulder...................................... 190.1 3,220
-------------------------
Combined--Total............................... 287 ...........
------------------------------------------------------------------------

We also reassessed the effective mass calculations in the 24.1 km/h
Ethafoam test. Effective mass was calculated in three different ways.
As was reported in the 1995 Advanced Glazing Report, we estimated the
effective mass as a function of time during the foam contact by using
eq. (2). Again, this is done for both the head and torso separately,
and is added for a total effective mass estimate. The estimate over
time was averaged to provide a single value of effective mass. However,
averaging over different time periods can result in very different
estimates of effective mass. The estimate below uses the time period
between when the peak force value is achieved to when the minimum
relative velocity between the dummy and the sled is achieved.

[[Page 3257]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.014

Where:

EM = effective mass
ay = acceleration in the y (lateral) direction

The second method used to calculate effective mass was to solve for
mass in the equation of kinetic energy by assuming that the estimated
impact energy is equal to the kinetic energy of the effective mass
prior to impact, as is shown in eq. (3).
[GRAPHIC] [TIFF OMITTED] TR19JA11.015

Where:

Ei = Energy of impact
Vy0 = Lateral velocity relative to sled just prior to
foam contact

The third and final method was to use impulse moment equations by
integrating the force applied to the dummy and dividing by the change
in velocity relative to the sled. This is shown in eq. (4).
[GRAPHIC] [TIFF OMITTED] TR19JA11.031

Where:

Vyf = Lateral velocity relative to sled at maximum foam
compression
tf = time of maximum foam compression (minimum relative velocity)

The estimates of effective mass of the combined head and shoulder
from all three methods, which range from 12.2 to 13.1 for the 24.1 km/h
impact, are shown in the fourth through the fifth columns in Table 34.
The impulse method estimate is lower than the other two estimates,
which match very closely. The second column in Table 34 shows the
individual values of impact speed for the head and shoulder.

Table 34--Impact Energy on the Ethafoam Padding in the 24 km/h Sled Test From Measured Force and Acceleration
Data
----------------------------------------------------------------------------------------------------------------
Method of Effective Mass Determination (kg)
--------------------------------------------------------
V0 (m/s) Avg. Accel. (eq.
2) Energy (eq. 3) Impulse (eq. 4)
----------------------------------------------------------------------------------------------------------------
Head................................ 6.85 4.32 4.14 4.19
Shoulder............................ 6.53 8.58 8.92 7.97
----------------------------------------------------------------------------------------------------------------
Combined........................ ................. 12.9 13.1 12.2
----------------------------------------------------------------------------------------------------------------

The estimate of impact energy can also be made other than by using
eq. (1). An alternate method rearranges the terms in eq. (3) and uses
the effective mass in combination with the pre-impact dummy speed. If
an effective mass of 13 kg were used in combination with a theoretical
impact speed of 24.1 km/hr (6.71 m/s), the energy generated would be
293 J. Based on the above analysis, we believe that a reasonable
estimate for the combined head and shoulder effective mass and energy
for a 24.1 km/h impact to be 13 kg and 290 J, respectively. We can
correlate this energy value to the ejection mitigation test procedure
by assuming an impactor mass of 18 kg. The corresponding impact
velocity is 20.5 km/h.
16.1 km/h Test
We also reanalyzed the 16.1 km/h testing with the dummy midsagittal
plane oriented 25 degrees from the vertical (rollover configuration).
The analysis of this test configuration was more complex, mainly
because the coordinate system of the dummy was not aligned with that of
the sled, and changed as the sled moved and particularly as the dummy
interacted with the foam padding. We initially compensated for the
dummy orientation by dividing the component of the local y (lateral)
accelerometer values by the cosine of 25 degrees. Single and double
integration is required to calculate the dummy velocity and
displacement, respectively. Table 35 below shows the estimated impact
energy on the Ethafoam padding in the 16.1 km/h sled test test using
the same methods as used for the 24.1 km/h test. Application of eq. (1)
for the head and a similar equation for the shoulder provided the
estimate of impact energy shown in the fifth column of Table 35, below.
We also generated the effective mass values by use of eq. (4), shown in
the third column of Table 35. We used this effective mass estimate and
the velocity relative to the sled of the head and shoulder at contact
with the foam to estimate the incoming kinetic energy by rearranging
the terms in eq. (3), shown in the fourth column of Table 35.\109\
---------------------------------------------------------------------------

\109\ As discussed below, the actual sled speed at the time of
dummy contact with the foam was 15.2 km/h (4.24 m/s) to 15.5 km/h
(4.30 m/s) and lower than the intended sled speed of 16.1 km/h (4.47
m/s).

[[Page 3258]]

Table 35--Impact Energy on the Ethafoam Padding in the 16.1 km/h Sled Test From Measured Force and Acceleration
Data
----------------------------------------------------------------------------------------------------------------
Vo (m/s) EM (eq. 4) Energy (eq. 3) Energy (eq. 1)
----------------------------------------------------------------------------------------------------------------
Head................................ 4.84 6.7 kg 78.5 J 68.3 J
Shoulder............................ 4.06 13.1 kg 108 J 92.5 J
Combined........................ ................. 19.8 kg 187 J 161 J
----------------------------------------------------------------------------------------------------------------

We do not have a great deal of confidence in the energy values
presented in Table 35, particularly in the estimate using eq. (1). As
stated above, these estimates require integration of the dummy head and
T1 acceleration values. To the extent the dummy head or torso becomes
misaligned with the 25 degree tilt prior to and after foam contact, the
integration of the sensor readings compounds the error in estimated
velocity and displacement. Differences in the calculated initial head
and shoulder velocity of 4.84 m/s and 4.06 m/s, respectively, are
indicative of dummy rotation prior to foam contact. Examination of the
video confirmed the rigid body rotation during dummy free-flight and
after foam contact. Short of performing a much more rigorous video
analysis of the test films, we opted for another strategy to estimate
the energy of the 16.1 km/h impact configurations.
One strategy we employed was based on the fact that the
constitutive properties of the foam for both the 16.1 km/h impact into
the Ethafoam padding and 24.1 km/h impact into Ethafoam did not change,
i.e., the foam properties did not change. Based on this, we attempted
to derive the dummy motion in the direction of force applied by the
foam. We assumed that once in contact with the foam, the lateral force
on the head or shoulder of the dummy can be represented by a mass on a
spring, in parallel with a viscous dashpot. To simplify this analysis
we assume the damping coefficient is zero and the force on the mass is
simply a function of the spring stiffness (F = -ky). We can thus
represent the energy stored in a spring, as shown in eq. (5).
[GRAPHIC] [TIFF OMITTED] TR19JA11.016

Where:

Es = Energy stored in a spring

Using this concept we can derive eq. (6) to determine the impact
energy of the 16.1 km/h test since we know the energy of the 24.1 km/h
impact and the forces measured at the foam pads for each impact speed.
The head and shoulder impact energies have ratios of 61 percent and 75
percent, respectively. The resulting estimate of total impact energy
for the 16.1 km/h impact is 202 J. Using this energy value and the
estimate for initial head and shoulder velocity as inputs to eq. (3),
the effective mass for the head and shoulder are 5.1 kg and 17.3 kg,
respectively. The combined effective mass is 22.3 kg. The results are
given in Table 36.
[GRAPHIC] [TIFF OMITTED] TR19JA11.017

Table 36--Impact Energy and Force on the Ethafoam Padding in the 16.1 km/h Sled Test Estimated From a Spring
Model
----------------------------------------------------------------------------------------------------------------
Max. energy (J) Max. force (N) Ratio of energy Effective mass
----------------------------------------------------------------------------------------------------------------
Head................................ 59.2 2,005 60.9% 5.05
Shoulder............................ 143 2,789 75.0 17.3
---------------------------------------------------------------------------
Combined........................ 202 ................. ................. 22.3
----------------------------------------------------------------------------------------------------------------

Another strategy employed to estimate the energy of the 16.1 km/h test
was based on the assumption that the estimate of sled velocity was a
better representation of the dummy impact speed than the speed derived
from the dummy accelerometers. The second column in Table 37 shows the
sled speed just prior to dummy head and shoulder contact. Equation 4
can be used to estimate the effective mass if the time (tf)
of minimum relative dummy to sled velocity (vyf) is known.
However, the only estimate of this time is from the single integration
of dummy accelerometers. Nonetheless, the EM and energy of impact,
using eq. (3), are given in Table 37.

Table 37--Head Impact Energy Into the Ethafoam for the 16.1 and 24.1 km/h Tests, Estimated by Assuming Sled
Velocity Equals the Impact Velocity
----------------------------------------------------------------------------------------------------------------
EM (eq. 6.6.4) Energy (eq.
Vo (m/s) (kg) 6.6.3)
----------------------------------------------------------------------------------------------------------------
Head.................................................. 4.30 7.53 69.5 J
Shoulder.............................................. 4.24 13.8 124 J
Combined.......................................... ................. 21.4 194 J
----------------------------------------------------------------------------------------------------------------

By using the spring equation assumption (Table 36) and sled
velocity rather than dummy sensor estimates for initial impact speed
(Table 37), we estimate an effective mass range of 21.4 to 22.3 kg and
an energy range of 194 to 202 J. We believe this range of estimates is
superior to the energy and effective mass values using only dummy
sensor derived estimates of dummy velocity and displacement (Table 35),
particularly the estimate using eq. (1).

[[Page 3259]]

Thus, we believe that it is reasonable to estimate the effective mass
and energy of the 16.1 km/h test as 22 kg (6.3 kg for the head and 15.6
kg for the shoulder) and 200 J, respectively.
Finally, we note that if the test had been actually performed at
16.1 km/h (4.47 m/s) rather than the actual value of approximately 15.5
km/h (4.3 m/s), the energy estimate for the test would be higher. There
is no reason to believe that if the test were performed at a higher
speed that it would change the effective mass estimate. Thus, if we use
the 22 kg effective mass estimate, the impact energy at 16.1 km/h would
be 220 J.
D. DRF Data
We also reanalyzed DRF data used in the NPRM and found an error in
the analysis of impact speed. In the NPRM (74 FR at 63196), we
discussed video analysis of data from the advanced glazing program of
vehicles tested on the DRF with a 5th percentile adult female dummy and
a 50th percentile adult male test dummy (near and far side).\110\ We
stated that video analysis of dummy head impact velocities with the
glazing showed that for the 5th percentile female far side occupant,
the time to glazing impact after the DRF began rotating was between 1.3
and 1.8 seconds, which was in the range of two to three quarter-turns
of rotation, and that the peak impact speed was 31 km/h. In Table 12 of
the NPRM (id.), we showed the estimated velocities for the near and far
side dummies.
---------------------------------------------------------------------------

\110\ Duffy, S., ``Test Procedure for Evaluating Ejection
Mitigation Systems,'' 2002 SAE Government/Industry Meeting.
---------------------------------------------------------------------------

After reanalyzing the data for this final rule, we determined that
the head impact speeds are approximately half of those reported in the
NPRM. Apparently the reason for this was an error in film rate
transcription during the original analysis. A reanalysis of the DRF
videos found peak head and shoulder speeds between 15 and 16 km/h, see
Table 38 below.\111\ There is no way to directly determine the energy
of the interaction between the dummies and the glazing in these DRF
tests. However, assuming an effective mass for the 50th percentile male
of 6.3 kg and 15.6 kg for the head and torso impact, respectively, the
resultant impact energy would be 209 J. We can correlate this energy
value to the ejection mitigation test procedure by assuming an impactor
mass of 18 kg. The corresponding impact velocity would be 17.3 km/h.
---------------------------------------------------------------------------

\111\ Videos and electronic data from these tests have been
placed in the NHTSA Component Database and can be accessed at www-nrd.nhtsa.dot.gov/database/aspx/comdb/querytesttable.aspx. Data from
four tests are under test number 716. The file names for the 5th
female near and far side tests are C00716C001 and C00716002,
respectively. The file names for the 50th male near and far side
tests are C00716C003 and C00716004, respectively.

Table 38--DRF Testing Peak Velocities
----------------------------------------------------------------------------------------------------------------
Impact speed (km/h) Estimated impact energy (J)
Dummy ---------------------------------------------------------------
Near Side Far Side Near Side Far Side
----------------------------------------------------------------------------------------------------------------
5th Female:
Head........................................ 7.2 14.5 .............. ..............
Shoulder.................................... 7.0 15.5 .............. ..............
50th Male:
Head........................................ 9.2 15.2 .............. 209
Shoulder.................................... 9.0 15.8
----------------------------------------------------------------------------------------------------------------

It is important to emphasize that this set of DRF tests was
performed at a peak roll rate of 330-360 deg./sec. An analysis of field
data submitted by Batzer and Ziejewski suggests that higher peak roll
rates can occur in the field.\112\ We would expect that if the DRF
testing were performed at a higher roll rate, that higher impact speed
would be possible. Modeling results provided by the agency in the NPRM
showed a Toyota pickup rollover simulation with a head and torso to
glazing speed of 20 and 16 km/h, respectively.\113\ This would result
in a total energy of 251 J, assuming a 22 kg effective mass.
---------------------------------------------------------------------------

\112\ An IMECE paper submitted with Batzer's comments indicates
that this range of peak roll rate is consistent with a 7-9 \1/4\-
turn rollover.
\113\ 74 FR at 63195.
---------------------------------------------------------------------------

E. Discussion and Conclusion
We agree with the importance of impact energy as a critical
parameter in the determination of the appropriate impact speed for the
18 kg impactor in the ejection mitigation test procedure, particularly
for a countermeasure consisting of side curtain air bags. Therefore, we
have endeavored to take a fresh look at the available data provided by
commenters and the data the agency used to justify the impact speed in
the NPRM. Based on our analysis, best available data have led us to
adopt an impact test speed of 20 km/h, consistent with Nissan's
comment, and the associated 278 J energy level.
We do not agree with requests by commenters to decrease the impact
speed to any level below the 20 km/h value. Honda requested a 17 km/h
impact speed (200 J), based on an analysis of peak head velocity and
effective mass involving belted occupants. We decline to restrict our
rulemaking to countermeasures that are subject to performance
requirements that account for the energy imparted on the side window by
belted occupants. The Alliance indicated that the appropriate impact
speed should be based on an energy of 178 Joules, resulting in a speed
of 16 km/h (4.44 m/s). We did not find the supporting GM and Ford
studies persuasive. We believe the use of the GM energy estimates as a
basis for the final rule is problematic because the rollover severity
used in the study only represents a small minority of the most harmful
ejection-inducing crashes. Also, the study seems to only measure, or
only contain, occupant loading through the head. We would expect
shoulder or combined shoulder and head loading to result in higher
energy estimates. The Ford modeling study also has limited usefulness
given that lack of specificity and detail provided about the modeling.
We have also determined that commenters' contention that the
agency's sled test data is supportive of only a 16 km/h impact to be
unfounded. Our analysis showed these tests represent energies from 220
to 290 J, which correlated to impact speeds in the range of 17.8 to
20.4 km/h.
We acknowledge that there are practical limitations to the level of
performance mandated by this Federal safety standard; the standard does
not reflect the worst case scenario. The speeds at which our sled tests
were run

[[Page 3260]]

did not generate the highest possible speeds that occupants in the
field could interact with the window opening. Some vehicles roll over
with a higher roll rate than generated by the DRF tests, resulting in
higher impact velocities than those measured in the laboratory, and
some occupants will weigh more than the dummies used or have a greater
proportion of their mass contact the window opening. Nonetheless,
ejection mitigation countermeasures installed pursuant to this standard
will provide a level of protection even under more dire conditions.
Moreover, this standard sets a reasonable, appropriate, and practicable
level of performance at a reasonable cost.\114\ It assures that
vehicles will be equipped with ejection mitigation countermeasures
suited to the energy generated in most rollover crashes. Consistent
with the agency's principles for sound regulatory decision-making, the
20 km/h impact test is data-driven and supported by all the technical
data available to date. A 400 J energy value has not been supported by
any of the technical assessments thus far conducted.
---------------------------------------------------------------------------

\114\ Some commenters said that unintended safety disbenefits
would result from a 24 km/h test, such as a greater risk to out of
position occupants or less protection in FMVSS No. 214 side impact
crashes. We respond to these commenters in a later section of this
preamble.
---------------------------------------------------------------------------

The FRIA discusses the impacts of adopting a 20 km/h test versus a
24 km/h test. We performed a sensitivity analysis comparing the harm
associated with crashes with an occupant impact speed of 20 km/h to
that of crashes associated with an occupant impact speed of 24 km/h,
and the resulting effect on the benefits analysis. This analysis
settles on a supposition that the difference between a 20 km/h test
speed and a 24 km/h test speed is about 7 percent of the overall
benefits of the final rule. Nonetheless, we have several reasons for
preferring the 20 km/h test requirement.
We have analyzed costs and other impacts associated with the 20 km/
h and 24 km/h criteria, and have found the 20 km/h test requirement to
be the most cost effective criterion. The FRIA compares the cost per
equivalent life saved of a 20 km/h rollover curtain air bag with that
of a 24 km/h rollover curtain air bag with a larger inflator (low end
of cost range) to achieve higher air bag pressure and a 24 km/h
rollover curtain air bag that has the same pressure as the 20 km/h
curtain, but has greater volume (high end of the cost range). It is
assumed that this system with greater volume requires additional air
bag material and an additional inflator for a vehicle with 3 rows or 2
rows and a cargo area. Using the 3 percent discount rate as a basis of
comparison, the 20 km/h system is the most cost effective at $1.4
million per equivalent life saved. This compares with a range in cost
for the 24 km/h system from $1.6 to $2.8 million.
Not only does the 20 km/h test requirement impose minimal costs for
the maximum benefit, a 20 km/h test requirement, as discussed above, it
is better supported by technical data than a 24 km/h requirement as it
better represents the forces to which the ejection countermeasure will
be exposed to in the field than a 24 km/h requirement, particularly in
rollovers.
Some vehicle manufacturers have commented that meeting a 24 km/h
requirement will entail increasing air bag pressure in current bags,
and have expressed concerns that more rigid bags will increase head
injury criteria (HIC) values measured in a side impact test and IARVs
measured in out-of-position (OOP) tests. Although whether those
increased HIC values and IARVs in OOP tests from increased air bag
pressure pose an unreasonable safety risk is not known, negative trade-
offs concern the agency in any rulemaking. Those possible trade-offs
can be avoided with a 20 km/h requirement. To illustrate, in agency
testing the MY 2007 Mazda CX9 was able to meet the 20 km/h performance
test at all locations tested, without modification. This vehicle has a
5-star side impact rating under the then-NCAP rating system.
Finally, some manufacturers pointed to their successful experience
with rollover curtains installed on their vehicles to argue that the
performance requirements of the proposed standard are too high. VW
stated that it was unaware of any ejections occurring in 100,000
Tiguan, Q7 and Q5 vehicles with sealed curtain side air bags. GM stated
that it started implementing ejection mitigation curtains with several
2005 model year vehicles and it is unaware of injuries due to ejection
past an ejection mitigation air bag. GM submitted case studies of
twelve rollover crashes investigated by GM and the University of
Michigan and found no ejections had occurred.
In response to VW, the fact that VW is not aware of any ejections
is not necessarily supportive of a conclusion that the ejection
mitigation systems in the vehicles are sufficient. A much more detailed
field data analysis of available rollover and side impact crashes would
be necessary. For example, such information would have to include the
number of rollover crashes, the number of quarter-turns, and the seat
belt status of the occupants. Even then, it is difficult to draw
conclusions from a limit number of crashes. Further, with regard to
GM's twelve cases, almost all of these cases involved belted occupants.
Our final rule focuses on ejection mitigation for both unbelted and
belted occupants.
In sum, based on our analysis of the comments and a reanalysis of
the basis for the impact tests, we have adopted an impact test speed of
20 km/h. We conclude that this level of energy is more representative
of the energy the ejection countermeasure will typically be exposed to
in the field, particularly in rollovers. Thus, the 20 km/h requirement
is reasonable, appropriate, and practicable, and preferable to the 24
km/h test requirement.

d. Target Locations

This section discusses the NPRM's proposals concerning where the
headform impactor will be aimed to assess the effectiveness of ejection
mitigation countermeasures, the comments received on the NPRM, and our
responses thereto. Because there are many issues relating to target
locations, to make the discussion easier to follow we respond to the
comments immediately after summarizing them issue by issue.
This final rule adopts the test procedures proposed in the NPRM for
locating target locations except as follows: (1) The window opening for
cargo areas behind the 1st and 2nd row will be impacted; (2) the
lateral distance defining the window opening is increased from 50 to
100 mm; and (3) if necessary, the headform and targets will be rotated
by 90 degrees to a horizontal orientation if this results in more
impact locations (up to a maximum of four targets per window) than the
vertical orientation. Additional changes include: instructing removal
of gasket material or weather stripping used to create a waterproof
seal between the glazing and the vehicle interior and the door and the
door frame; allowing some portion of material bordering a window
opening on the exterior of the vehicle to factor into our assessment of
what is a window opening; and permitting the adjustment or removal of
components that would interfere with the ejection impactor or headform
in the test.
1. Why We Are Focusing On Side Windows and Not Other Openings
In general, comments from glazing manufacturers and consumer groups
asked that the agency expand coverage to sun/moon roofs and backlights.
EPGAA stated that `[w]hile NHTSA addresses third row windows which

[[Page 3261]]

account for less than 1% of the injuries and deaths, it completely
ignores sun roofs and rear windows which are also window openings
through which outboard seated occupants could be ejected and together
account for over 12% of the injuries and 7% of the deaths.'' Public
Citizen (PC) commented that ``[t]he agency should consider whether
laminated glazing would counter the potential for ejection through the
roof, which can be expected to increase as a result of the side curtain
airbags that the standard requires.'' PC also mentioned that the PRIA
quoted a 2002 agency report that estimated that 15 percent of occupants
are ejected through sun roofs. Batzer and Ziejewski stated that NHTSA's
``statistics indicate that the most common windows acting as ejection
portals include the first row windows, the windshield, the sunroof, and
the backlite [sic].''
Agency Response
We do not grant the request from Advocates for ejection mitigation
coverage of doors and windshields. Door openings are already regulated
by FMVSS No. 206, ``Door locks and door retention components,'' which
was upgraded in 2009 expressly to improve door lock and hinge
requirements to reduce door openings in crashes. (72 FR 5385, February
6, 2007, Docket NHTSA-2006-23882.) Windshields are regulated by FMVSS
No. 205, ``Glazing materials,'' and the associated performance
requirements in FMVSS No. 212, ``Windshield mounting.'' No suggestion
was made as to how these existing requirements could be enhanced.
Ejection mitigation through the backlight and through movable or
fixed roof panels is not addressed by FMVSS Nos. 206, 205, or 212. Our
most recent analysis of ejection route data set forth in this final
rule and in the FRIA indicates that backlight and roof ejections rank
3rd, behind 2nd row window ejections.\115\ For all crash types the
backlight and roof represent 4.8 percent and 3.1 percent of fatalities,
respectively. When crashes are limited to target population crash
types, i.e., crashes involving lateral rollovers and side impact
crashes, the backlight and roof represent 5.9 percent and 3.9 percent,
respectively. Backlights are on nearly every vehicle and sun/moon roofs
are not, so given those data, if a roof opening is present, it
represents a greater risk for ejection than the backlight.
---------------------------------------------------------------------------

\115\ These rankings exclude ejections through non-glazing
areas.
---------------------------------------------------------------------------

In the updated data analysis for this final rule, we provide a much
more refined analysis of the roof ejections than was provided in the
NPRM. This was achieved by performing a manual review of each case. Our
analysis was able to segment the data by those with roof glazing (moon
roofs) and those with sheet metal panels (sun roofs) as well as the
pre-crash position of the panel. Closed moon roofs represent about half
the fatal and MAIS 3+ ejections through the roof.
To fully understand this issue, the agency has assessed the cost
effectiveness of using advanced glazing for the backlight and closed
roof glazing. This analysis, set forth in the FRIA, includes all crash
types (not limited to side impacts and rollovers) since the advanced
glazing countermeasure does not need to deploy. The results are given
in Table 39 at the 3 and 7 percent discount rates and at an assumed
ejection effectiveness level of 20 percent. The 20 percent
effectiveness value used in the FRIA is for illustration purposes. At
the 20 percent level of effectiveness, the backlight glazing does not
appear cost effective, while the roof glazing could be.

Table 39--Cost per Equivalent Life Saved (ELS) of Ejections through Backlight and Roof Glazing with Advanced
Glazing
----------------------------------------------------------------------------------------------------------------
Cost per ELS
--------------------------------------------------------------------------------
Assumed containment effectiveness Backlight Roof glazing
--------------------------------------------------------------------------------
3% 7% 7% 3%
-------------------------------------------------------------------------------------------------------------- ----
20%............................... $11.3M $14.2M $4.1M $5.1M
----------------------------------------------------------------------------------------------------------------

Commenters to the NPRM argued that the PRIA stated that after
implementation of FMVSS No. 226, roof ejections are likely to increase
from their current level as a result of occupants, contained from side
window ejections, being available for ejection from other portals. The
agency agrees this is a reasonable possibility. In fact, our findings
in analyzing the RODSS database cases with side curtains are consistent
with this conclusion.\116\ Commenters also indicated their belief that
roof ejections may increase due to more and larger sun/moon roofs in
the future. This forecast seems speculative since there was no data
provided to support it.
---------------------------------------------------------------------------

\116\ It is important to emphasize that the RODSS data is not a
statistically representative sample of field data.
---------------------------------------------------------------------------

In any event, we have determined it is not reasonable to expand
this final rule to roof glazing. A major impediment is the lack of a
proven performance test procedure for roof glazing. The current
configuration of an ejection propulsion mechanism and ejection impactor
has been years in development and is specially designed for horizontal
impacts on nominally vertical surfaces. A comparable performance test
will have to be developed that delivers an appropriate amount of impact
energy to a pre-broken roof glazing or the opening covered by some
other countermeasure.
Another factor that causes us not to expand this final rule to
address ejections through the roof is an absence of notice to the
public to add such a provision to the final rule. The public has not
been provided meaningful notice that NHTSA was considering requirements
for roof portals, and has not been provided an opportunity to comment
on such requirements. Relatedly, the agency has not been given the
benefit of the public's views of the matter. Accordingly, we are not
extending this final rule to roof glazing.
However, NHTSA is interested in learning more about roof ejections
and would like to explore this area further. We plan to examine field
data to better understand the current and future extent of roof
ejections, and will seek to learn about the future implementation of
sun/moon roofs in vehicles and ideas about effective ejection
countermeasures through those portals. The results of this work may
find that future rulemaking on roof ejections could be warranted.

[[Page 3262]]

2. Why We Are Focusing on the Side Windows Adjacent to First Three Rows
We received comments on which side window openings should be
subject to ejection mitigation requirements, and how the final rule
should determine the rear boundary that defines which rear window
openings are subject to the standard.
i. First Three Rows
Advocates believed that the rule should extend to ``occupants in
the rear seats of small buses and 15-passenger vans.'' Batzer and
Ziejewski stated that ``[t]he reasoning behind why only the first three
rows of seats are required to have coverage seems insufficient. Why
would not every designated seating position in every vehicle have the
same level of safety?''
Agency Response
The final rule will not extend side window coverage beyond three
rows. SAFTEA-LU directed us ``to reduce complete and partial ejections
of vehicle occupants from outboard seating positions.'' Our position in
the NPRM was that field data showed a compelling need for ejection
countermeasures to cover daylight openings adjacent to the first two
rows of seating coverage. The update of the field data presented in
this final rule supports this decision. For all crash types, the first
and second row windows rank 1st and 3rd (54.2 percent and 7.7 percent,
respectively) as far as fatal occupant ejection routes.\117\ When
crashes are limited to target population crash types, i.e., crashes
involving lateral rollovers and side impact crashes, these rankings
(50.3 percent and 7.7 percent, respectively) for fatal ejections do not
change.
---------------------------------------------------------------------------

\117\ These rankings exclude ejections through non-glazing
areas. The second ranked fatal ejection route is the windshield, for
both lateral rollovers and side impact crash populations.
---------------------------------------------------------------------------

Third row ejections are a very limited part of the ejection
population; in target population crashes they constitute only 0.3
percent and 0.7 percent of fatalities and MAIS 3+ injuries.
Nonetheless, we proposed coverage to three rows since many vehicles
already on the market with three rows of seating are equipped with
rollover deployable side curtain air bags that cover daylight openings
adjacent to all three rows. This trend toward third row coverage has
continued. Further, we wanted to cover as much of the side opening as
reasonably possible because we were concerned that, if only the first
two row windows were covered, in a rollover crash unbelted occupants
contained from ejecting through the first two windows could be ejected
from an uncovered opening adjacent to the third row. To reduce that
risk of ejection, and importantly, given that the ejection mitigation
side air curtains installed on current vehicles demonstrate the
practicability and cost-efficiency of a curtain spanning the side of
the windows from the first through third rows, we felt justified in our
decision to provide coverage of third row windows. Vehicles the agency
has tested for this rulemaking with air bag curtains covering rows 1, 2
and 3 windows are the MY 2005 Honda Odyssey, MY 2006 Mercury Monterey,
MY 2007 Chevrolet Tahoe, MY 2007 Ford Expedition, MY 2007 Jeep
Commander, MY 2008 Dodge Caravan, MY 2008 Ford Taurus X, and MY2008
Toyota Highlander. These designs are typically a single curtain
covering tethered at the A and D-pillars.
Insufficient reasons are available to support requiring side
daylight opening coverage into 4th and higher rows.\118\ Fourth and
higher row ejections are a very limited part of the ejection
population; in target population crashes they constitute only 0.6
percent and zero percent of fatalities and MAIS 3+ injuries,
respectively. Extending coverage to 4+ rows goes beyond curtain air bag
coverage that we have seen on any vehicle. It may be possible
technically to extend a single curtain air bag to cover beyond 3 rows,
or conceivably manufacturers could use two curtain air bags to cover
the entire side of the vehicle. However, for a two curtain system
without intervening pillars there is likely a need to tether the
curtains together in order to provide tension near the curtain bottoms.
We do not know if curtains tethered together will be able to meet the
performance requirements of the standard adopted today. Moreover,
depending on the design, the costs for covering windows adjacent to 4+
rows may be substantial.
---------------------------------------------------------------------------

\118\ 74 FR 63201
---------------------------------------------------------------------------

Glazing manufacturers have indicated that some vehicle
manufacturers place advanced glazing in fixed window positions in the
rearmost rows of large vans. However, we have not tested these glazing
applications to the adopted requirements, nor has any data been
submitted to the agency. Thus, the performance of a glazing-only
application in these higher rows is not known to us.
Given the above uncertainties about the availability and cost of
countermeasures that could be used to cover windows adjacent to 4+
rows, and in view of the small numbers of ejections through those
windows, we decline to extend this final rule to window openings beyond
the 3rd row.
ii. Method of Determining 600 mm Behind Seating Reference Point (SgRP)
The Alliance commented that limiting the daylight opening to 600 mm
behind the SgRP of the last row seat or behind the rearmost portion of
a seat not fixed in the forward seating direction, in combination with
the targeting method, ``can result in targets being located in cargo
areas and/or behind and below seat backs and head restraints.'' The
Alliance believed that rearward occupant motion is resisted by the seat
back and head restraint and that this is not considered by the ``600 mm
method.'' It also stated its belief that the combination of seats and
seat belts ``greatly reduces the risk of head and upper torso ejection
in the area created by the proposed `600 mm' method.''
The Alliance suggested an alternative of using the Head Restraint
Measurement Device (HRMD) defined in FMVSS No. 202a to establish the
rearward extent of the head. This approach would provide the limit of
the daylight opening in the 3rd or last row.
Honda suggested that the fact that the 600 mm limit in FMVSS No.
226 is the same as in FMVSS No. 201 may not be appropriate when
considering that FMVSS No. 201 has a different basis and objective than
that of ejection mitigation. Honda suggested a different procedure to
determine the daylight opening limit, which takes into consideration
the movement of belted occupants in rollovers as well as the many fore-
aft and seat back angle adjustments. Honda's method is based on the
height of a 95th percentile occupant, with 200 mm added (1,018 mm) to
account for upward movement of a belted occupant during a rollover. A
1,018 mm radius arc is centered at the SgRP and swept through the
daylight opening. A reference line is drawn parallel to the torso line
and translated 155 mm rearward and perpendicular to the torso line. The
arc and the rear reference line provide the boundaries for the daylight
opening.
NTEA stated, ``NHTSA [should] consider adopting testing parameters
similar to those found in [S6.3(b)] FMVSS 201 to effectively exclude
any targets that are located behind the forward surface of a partition
or bulkhead * * * . We believe it is neither practical nor beneficial
to require test target points that could not possibly be contacted by
the head of an occupant seated forward of the partition.''

[[Page 3263]]

Agency Response
The Alliance objected to the 600 mm limit because it ``can result
in targets being located in cargo areas and/or behind and below seat
backs and head restraints.'' The Alliance's comment suggesting that
seat belts would reduce the risk of an occupant's head and torso being
ejected in the area behind the seat back and head restraints is not
consistent with this final rule's goal of reducing partial and full
ejections of belted and unbelted occupants. Similarly, the suggested
use of the HRMD to define the limit of the opening in the third row
disregards that this final is intended to protect belted and unbelted
occupants.
It is correct that the 600 mm limit can result in target areas in
the cargo area and/or behind and below the seat back. We chose that
limit to address what can occur in the field. Our field data
assessment, discussed in section IX.b. and in our technical report, has
several cases where occupants were ejected rearward of their initial
seated position. In RODSS case 5032 (SCI CA09061) a driver was
completely ejected through the left 3rd row quarter panel window. In
NASS case 2006-79-89 the driver was partially ejected from the left 2nd
row window. In SCI case DS04016, an infant seated in the middle of the
2nd row was ejected through the 3rd row quarter panel window.
These cases demonstrate how rollovers, particularly of the long
duration multiple quarter-turn variety, are chaotic events with complex
vehicle and occupant kinematics that can result in occupants moving
rearward of their seating position. In addition, rollovers can be
preceded by planar impacts with a substantial rearward component,
resulting in occupants moving towards the rear of the vehicle. The bulk
of the benefits from this standard are for unbelted occupants. The
limitations suggested by the vehicle manufacturers are not consistent
with protecting this population. For the agency, the issue is not
whether the standard will cover some area rearward of a seating
position, but how far behind the seating position.
We decline to adopt Honda's technical method for limiting the
daylight opening. Our technical report explains that the Honda method
would result in a smaller area of coverage and potentially fewer impact
targets than the NPRM method. Briefly stated, a small part of the area
described by Honda would actually be farther rearward than the NPRM
limit. However, the Honda derived limit has a smaller area overall. For
some large windows, using the Honda method results in only two targets
fitting in the window opening, whereas the NPRM's method results in
four impact locations. Further, the Honda method increases the
complexity of the standard.
Honda suggested that selection of a 600 mm rearward limit, to the
extent that it is potentially based on FMVSS No. 201, may be too great
a distance. We do not agree on this point. To the extent that FMVSS No.
201 attempts to protect occupants from interior impact in all crash
modes, including rollovers, we believe that FMVSS No. 226 should be no
less expansive in its rearward coverage than FMVSS No. 201. Moreover,
since rollovers make up the largest portion of the target population
for FMVSS No. 226, and because rollovers result in more chaotic
occupant motion than any other crash type, it is our view that FMVSS
No. 201's coverage should not prescribe the limits of the coverage of
FMVSS No. 226.
The suggestions of the Alliance and Honda to reduce the 600 mm
value will dampen the effectiveness of this final rule in protecting
unbelted occupants in rollovers. Accordingly, we deny the requests. (We
respond to NTEA's suggestion in the ``Vehicle Applicability'' section
of this preamble.)
iii. Increasing 600 mm Limit for Vehicles With One or Two Rows of Seats
The NPRM proposed to limit the requirement to provide side daylight
opening coverage to an area bounded by a plane 600 mm behind either the
SgRP of a seat in the last row (for vehicles with fewer than 3 rows) or
the SgRP of a seat in the 3rd row (for vehicles with 3 or more rows).
As a result, for a vehicle with only one or two rows and with a cargo
area behind the seats, all or part of the cargo area daylight opening
rearward of that 1st or 2nd row would have been excluded under the
NPRM.
After reviewing the comments from glazing manufacturers and
Advocates and the updated field data showing the prevalence of
ejections through side glazing in the area of the first three rows, we
have reconsidered the proposed 600 mm limit for vehicles with less than
3 rows. We have also reconsidered this issue after reflecting on AIAM's
comment which asked for clarification on whether a vehicle having
windows to the rear of the last row of seats (e.g., 2 rows of seats but
a third side window next to the rear cargo area) would be subject to
testing of the third side window.
Agency Response
For vehicles with only one or two rows of seating, we have decided
to increase the 600 mm distance to 1,400 mm, measured from the SgRP of
the seat in the last row. By extending the distance to 1,400 mm, we are
subjecting more area of glazing to testing, i.e., more of the glazing
area in cargo area behind the 1st or 2nd row will need an ejection
mitigation countermeasure. The window openings subject to testing under
the 1,400 mm limit are those that would have been adjacent to a third
row seat had the vehicle had a third row.
There is a safety need to cover this cargo area. In the NPRM (see
Tables 16 and 17 of the NPRM preamble), we provided the distribution of
ejected occupants by ejection route for all crashes. In these data
tables, we did not have a category for cargo area ejections because
data were not available. For this final rule, we undertook a manual
review of each case to update ejection route data provided earlier in
this preamble. In that review, we found that 0.5 percent of ejections
in all crashes (and target population crashes) were ejected through the
cargo area behind the 2nd row.\119\ This is slightly more than the
percentage for 3rd row ejections.
---------------------------------------------------------------------------

\119\ There were no ejections through the cargo area windows
behind any other row.
---------------------------------------------------------------------------

Further, our field data assessment discussed in section IX.b
included a number of cases where occupants were ejected rearward of
their initial seated position. As described earlier, in RODSS case 5032
(SCI CA09061), a driver was completely ejected through the left 3rd row
quarter panel window. In NASS case 2006-79-89, the driver was partially
ejected from the left 2nd row window. In SCI case DS04016, an infant in
the middle of the 2nd row was ejected through the 3rd row quarter panel
window. These cases demonstrate how rollover crashes are complex
turbulent events that can propel unbelted occupants rearward in the
vehicle. Rollovers involving planar impacts having a substantial
rearward component can thrust an unbelted occupant rearward toward the
rear window openings in a manner unlike other crash types.
Vehicles are already being produced that have side air bag curtains
covering rows 1, 2 and 3 row windows (e.g., the MY 2005 Honda Odyssey,
MY 2006 Mercury Monterey, MY 2007 Chevrolet Tahoe, MY 2007 Ford
Expedition, MY 2007 Jeep Commander, MY 2008 Dodge Caravan, MY 2008 Ford
Taurus X, and MY 2008 Toyota Highlander). The designs typically use a
single curtain

[[Page 3264]]

covering tethered at the A- and D-pillars.\120\ Since there are designs
that provide three rows of coverage, we believe that covering the cargo
area behind the 1st or 2nd row of a vehicle up to window openings
adjacent to where a third row would have been, offers no more of a
technical challenge than manufacturers face in covering all openings
adjacent to the 3rd row for vehicles with three rows.
---------------------------------------------------------------------------

\120\ The MY 2007 Chevrolet Tahoe uses a separate curtain to
cover the 3rd row window.
---------------------------------------------------------------------------

Our FRIA calculates the cost effectiveness of extending a two-row
curtain to cover the cargo area behind the second row and finds that it
has a similar level of cost effectiveness as 3rd row coverage.\121\
Accordingly, it is reasonable and appropriate for this final rule to
include impact targets in window openings in the cargo area behind the
1st and 2nd row for vehicles with one or two rows of seating, if the
window openings are located where they would have been adjacent to a
third row seat had the vehicle had a third row.
---------------------------------------------------------------------------

\121\ These cost effectiveness estimates are based on the cargo
area and/or 3rd row area coverage alone. If they were to be lumped
together with the first 2 rows of coverage, they become even more
cost effective.
---------------------------------------------------------------------------

We have determined that a third row seat would have been
encompassed in an area bounded by a transverse plane 1,400 mm behind
the rearmost SgRP of a first row seat (for vehicles with only one row
of seats) or a second row seat (for vehicles with two rows of seats).
Thus, we are extending the NPRM limit for these vehicles that have a
cargo area behind the first or second row and no other row of seats, by
800 mm. We arrived at the 1,400 mm value through a small study of
curtain coverage length of late model 3 row vehicles beyond the 2nd row
SgRP. This study included 14 of the MY 2006 to MY 2009 vehicles that
were in the agency impactor testing program. These vehicles had 3rd row
rollover curtains or curtains covering the cargo area behind the second
row. Our measurements indicated that a 1,400 mm dimension rearward from
the 2nd row SgRP would cover the entire daylight opening area for all
except one of the vehicles.\122\
---------------------------------------------------------------------------

\122\ More details of this study can be found in the technical
report supporting this final rule.
---------------------------------------------------------------------------

The final rule will maintain the 600 mm value for vehicles with 3
or more rows.
3. Answers to Questions About Method for Determining Three-Row Area
i. AIAM and Hyundai asked: (a) Is the targeting procedure done on
the entire daylight opening and then the targets are limited to those
that are in the area forward of the 600 mm line; or (b) is the
targeting procedure done only on the area forward of the 600 mm line.
In addition, if (a) above is the answer, Hyundai sought clarification
on whether the entire target outline needs to be located in the
daylight opening or just the center of the target outline.
Our response is that the targeting procedure is performed on just
the area forward of the 600 mm line (the second answer above), for a 3
row vehicle. (As indicated above, this final rule specifies this
dimension as 1,400 mm for vehicle with fewer rows.) Proposed
S5.2.4.2(a) stated in part that ``the transverse vertical vehicle plane
defines the rearward edge of the daylight opening for the purposes of
determining target locations.'' The regulatory text adopted by this
final rule (at S5.2.1.2(a)) slightly modifies the proposed text by
indicating that the transverse vertical plane defines the rearward edge
of the offset line (rather than the daylight opening) for the purposes
of the targeting procedure performed on the daylight opening. To
reiterate, the wording does not specify that the targeting procedure is
performed on the entire opening and then only the targets forward of
the 600 mm limit are used.
ii. NTEA asked if side daylight openings behind occupants of side
facing seats would be subject to the standard since the SgRP is
parallel to the opening. Similarly, for rear facing seats, NTEA asked
whether the side opening associated with such a seat is tested and
would glazing on the opposite side of the vehicle be tested. Finally,
NTEA asked if there was a lateral distance from any side glazing to the
SgRP of a forward or rear-facing seating location, beyond which the
requirements for the testing would not apply.
Our answer is that daylight openings adjacent to both side and rear
facing seats are potentially required to be targeted if they are part
of the first three rows of seating. The definition of ``row'' adopted
by the standard is still applicable. If these seats are fixed in a side
or rear facing direction, the SgRP is not used to determine the
rearward limit of the daylight opening. Rather, the limit is determined
by the location of a vertical lateral vehicle plane located behind the
rearmost portion of the rearmost seat. See proposed S5.2.4.2(a) and
(b), and S5.2.1.2(a) and (b) in this final rule.
Daylight openings on either side of the vehicle are subject to
testing even if the seat or seats in that row are on the opposite side
of the vehicle. There is no limit on lateral distance from a seat to a
daylight opening that would exclude an opening from coverage. Crash
data from the field have shown that an occupant on one side of a
vehicle can be ejected out of an opposite side window. These provisions
are to reduce the likelihood of such ejections.

e. How We Are Testing The Ability Of These Side Windows To Mitigate
Ejections

1. What is a ``Window Opening''?
The NPRM proposed to define ``side daylight opening'' as--

other than a door opening, the locus of all points where a
horizontal line, perpendicular to the vehicle vertical longitudinal
plane, is tangent to the periphery of the opening, including the
area 50 millimeters inboard of the window glazing, but excluding any
flexible gasket material or weather stripping used to create a
waterproof seal between the glazing and the vehicle interior.
i. 50 mm Inboard of the Glazing
Reference to the area 50 mm inboard from the window glazing was
intended to account for interior vehicle structure that might be in the
vicinity of the daylight opening, which could restrict the size of the
opening through which an occupant could be ejected. In other words, we
wanted to include, as part of the opening, vehicle structures that were
within 50 mm of the window opening, if those structures could restrict
ejection through the opening.
The Alliance generally agreed with the proposed definition of
daylight opening, except the commenter suggested extending the distance
from the inside of the window glazing from 50 mm to 200 mm. The
Alliance believed that the proposed 50 mm value ``may result in
structures or trim proximal to the daylight opening to be removed to
gain access to a target location. Removal of these structures or trim
could result in an unintended consequence of laboratory performance
reduction of the ejection mitigation countermeasures.''
AIAM did not request a change in the 50 mm value, but rather asked
for clarification about the inclusion of ``items of trim such as grab
handles [that] may extend into the window area, potentially interfering
with the motion of the impactor during a test.'' AIAM suggested that
the standard specify one of the following: removing the trim item prior
to the test, adjusting the target location so that the trim item is not
engaged during impactor movement, conducting the test notwithstanding
the interference of the trim item, or eliminating the target from
testing requirements. Similarly, Honda and Hyundai requested guidance
on

[[Page 3265]]

positioning and/or removal of interior components, such as sun visors,
the instrument panel, interior and exterior mirrors, and grab handles.
Hyundai stated ``certain interior structures which do not restrict the
size of the daylight opening could still interfere with the linear
travel of the impactor headform in the area 50 millimeters or more
inboard toward the vehicle centerline from the window glazing interior
surface.''
Nissan asked that testing be performed without the headliner. It
stated: ``Nissan does not anticipate the headliner affecting
performance of the side curtain air bag system. Though the headliner
might affect the initial trajectory of the deploying side curtain air
bag, the proposed delay times of 1.5 seconds and 6 seconds ensure
sufficient time for full deployment, allowing the curtain air bag to
correctly position itself prior to contact with the impactor. Replacing
the headliner between tests would unnecessarily increase test
complexity and could result in lab error.''
Agency Response
We believe the Alliance's request that the definition for side
daylight opening be modified to increase the 50 mm distance inside the
window has some merit. We have examined interior trim components, such
as panels covering the vehicle pillars, and found that surfaces that
should be considered as part of the outline of the daylight opening can
be more than 50 mm inside the window glazing. Figure 12 is a schematic
showing the cross-section of a hypothetical door panel and glazing
whose horizontal tangent is 60 mm inside the glazing. Based on the
vehicles we examined, we believe that increasing the distance to 100 mm
will be sufficient to encompass interior borders and other components
around the daylight opening that might not be easily removed and whose
removal may have an unknown effect on the performance of the
countermeasure. These components could have a positive effect on
ejection mitigation, so our decision is that the determination of the
side daylight opening should be made with the components in place.
[GRAPHIC] [TIFF OMITTED] TR19JA11.018

We will not increase the distance to 200 mm, however. A 200 mm
distance is excessive and potentially includes more vehicle components
in the determination of the window opening periphery than necessary.
Although the linear impactor travels along a lateral horizontal path,
during a rollover, people moving towards the window opening would not.
Objects 200 mm from the window opening may have no ability to limit the
potential for ejection. The Alliance did not provide a rationale
justifying a 200 mm limit.
One concern we had relative to increasing the inboard distance from
50 mm to 100 mm was that even the 100 mm distance increases the
possibility of including inappropriate vehicle components in the
determination of the periphery of the window opening. The components
should not be included because they are not relevant to the actual
ejection portal, i.e., they are unlikely to have a positive effect in
mitigating ejection.
One of these components is the vehicle seat. In S6.3 of the
proposed regulatory text, we expressly specified that the seat may be
removed to conduct the test in an uncomplicated manner. Relatedly, in
view of our increasing the inboard distance defining the opening to 100
mm, the final rule at S3 will specifically exclude seats from
consideration in the definition of daylight opening.
Similarly, the agency also believes that we should expressly list
grab handles as components that will not be included in the
determination of a ``side daylight opening.'' Both Hyundai and AIAM
asked for clarification of the treatment of grab handles. Hyundai's
comments showed two examples of grab handles that were both outside of
the 50 mm limit (108 mm and 75 mm) proposed in the NPRM. At a distance

[[Page 3266]]

limit of 100 mm, one of these grab handles would be included, unless
specifically called out for exclusion.
We believe grab handles should be excluded from contributing to the
daylight opening for several reasons. First, we think it unlikely that
they will contribute anything positive to ejection mitigation. Second,
we believe there is a possibility that grab handles could interfere
with the ejection impactor in the test. The final rule will add them to
the definition of side daylight opening in S3 as an item that is
excluded from consideration in the definition of the daylight opening
(and to S6.3 as an item that can be removed if it obstructs the path of
the travel).
ii. Conducting the Test With Various Items Around the Window Opening
The comments from AIAM, Honda, and Hyundai also extend to items of
interior structure, aside from grab handles, that are not included in
the definition of the daylight opening (because they have no potential
for mitigating occupant ejection), but could restrict the travel of the
impactor headform. AIAM suggested multiple ways of handling these items
other than their removal, i.e., changing the target position,
eliminating a target, or performing the test with the item in place. In
the NPRM, S6.3 specifically allowed for the removal of seats and the
steering wheel. Our goal was to make sure the testing could be
performed, even if these items need to be removed, as these items would
provide no impediment to ejection in the real world.
We agree with AIAM, Honda, and Hyundai that there is a need to
provide more specificity in this part of the standard (S6.3 and S6.4 of
the final rule). One item mentioned by commenters was the exterior
mirror. We believe this component is worthy of specific mention in the
regulatory text as being an item that should be removed or adjusted so
as not to impede the motion of the headform beyond the vehicle. As
indicated by the National Forensic Engineers in its comments, exterior
mirrors may break off during rollovers and are unlikely to have a role
in mitigating ejection.
In the final rule, S6.3 will now specify that steering wheels,
seats, grab handles and exterior mirrors may be removed or adjusted to
facilitate testing and/or provide an unobstructed path for headform
travel through and beyond the vehicle. In addition, we have added the
steering column to the list since it is attached to the steering wheel
and may be the means by which the steering wheel is removed or
adjusted.
Beyond these components mentioned in S6.3, there are others that
may obstruct the impactor path. For example, one could conceive of a
rear drop-down entertainment center that blocks the upper targets. To
address these items, S6.4 in the final rule will indicate that other
vehicle components or structures may be removed or adjusted to provide
an unobstructed path for the headform to travel through and beyond the
vehicle.
Nissan requested that the final rule allow testing on a ``cut
body'' and not a fully trimmed vehicle. It also requested that testing
be done without the headliner since Nissan believes that the headliner
will not affect the test results, but may instead result in laboratory
error. Similarly, TRW wanted testing on a buck to be allowed.
We decline to make these changes requested by Nissan and TRW in the
final rule. Manufacturers are free to conduct certification testing
without the headliner, or on a cut body or test buck, as long as they
are assured that the vehicle would meet FMVSS No. 226 when tested by
NHTSA in the manner specified in the standard. We particularly
understand why manufacturers might want to test on a cut body or buck
during developmental testing. However, the agency prefers to test a
vehicle in as near the as-manufactured condition as practicable, to
better ensure that the performance we witness in the compliance
laboratory is representative of the performance of the vehicle in the
real world.
However, we recognize that there are practical difficulties of
testing the ejection mitigation countermeasure in a laboratory. We have
decided that S6.4 in the final rule will include language specifying
the adjustment or removal of vehicle structure that interferes with the
ejection propulsion mechanism and headform travel, but only to the
extent necessary to allow positioning of the ejection propulsion
mechanism and unobstructed path for the headform to travel. It has been
our experience that for daylight openings that are not located in
doors, there may be limited access on the opposite side of the vehicle
to pass the impactor propulsion mechanism through. This may then
require removal of a fixed window and or cutting of sheet metal to
allow access on the non-tested side of the vehicle. These modifications
will not affect the results of the impact testing.
iii. Removing Flexible Gasket Material For the Purpose of Determining
the Daylight Opening
To keep the test area as large as possible, the proposed ``daylight
opening'' definition excluded any flexible gasket material or weather
stripping used to create a waterproof seal between the glazing and the
vehicle interior. Flexible material is unlikely to impede occupant
ejection through the opening.
Honda stated that while it understood the agency's desire to
exclude gasket material from the daylight opening definition, it was
concerned about the material being difficult to remove or damaged
during removal for determination of the opening. Honda proposed an
alternative where the gasket material is included in the daylight
opening, but the 25 mm offset line defined in proposed S5.2.1(b), is
decreased. It stated that this ``retains the intention of addressing
occupant ejection through side glazing, but test repeatability and
validity are better assured.'' Similarly, TRW recommended that the
opening be measured considering any gasket/weather stripping as
potentially defining the opening, but the offset line be 20 mm from the
opening rather than 25 mm. Honda stated that manufacturers would not
enlarge the gasket material to reduce the daylight opening because of
``styling, appearance and consumer acceptance.'' Nissan stated that
``removing this [gasket] material prior to the test could expose the
side curtain air bag system to sharp edges on the vehicle that it would
not normally be exposed to during deployment and adversely affect
system performance.''
Both the AORC and TRW recommended that the agency obtain CAD data
from the vehicle manufacturers and use this to determine the daylight
opening and offset line. They believed that this would obviate the need
for removal and reinstallation of the gasket/weather stripping, which
they believed could lead to potential test variability.
Guardian, a glazing supplier, commented that: ``The NPRM defines a
window opening as the `daylight opening' (page 63204). We believe the
opening should include all related trim and gaskets that could be
removed with the glass in a rollover situation.''
In contrast, Takata indicated agreement with the proposed method of
determining the target location.
Agency Response
We disagree with commenters that wish to allow gasket material or
weather stripping to have a part in defining the opening. We continue
to believe that this has the potential of causing an unnecessary
reduction in the size of the opening, which may reduce the stringency
of the test.

[[Page 3267]]

Most commenters wishing to include gasket material in the
definition were concerned about potential test problems associated with
removal and reinstallation of this gasket material or weather stripping
in order to determine the daylight opening. We address the issue of
testing with this material in the next section. In summary, we do not
share this concern.
Both AORC and TRW suggested that CAD information submitted by
manufacturers could be used by the agency to define the daylight
opening, rather than removing any gasket material. It is certainly true
that the agency can ask for information from manufacturers and this has
been done for other FMVSSs \123\ and is a part of FMVSS No. 226's
framework concerning the rollover sensor.\124\ However, we do not
believe such a requirement is needed regarding the measurement of the
window opening. We prefer to have a test procedure within the
regulatory text of the standard that we can use to independently assess
factors used in the compliance test, such as the size of the window
opening, rather than depend upon information provided by the
manufacturers.
---------------------------------------------------------------------------

\123\ For example, S22.4.1.2 of FMVSS No. 208 requires knowledge
of the volumetric center of the static fully inflated air bag. The
agency requires this information from vehicle manufacturers.
\124\ The agency can ask the manufacturer to provide information
about the rollover sensor's deployment capabilities. See proposed
S4.2.4, Technical Documentation.
---------------------------------------------------------------------------

TRW and Honda suggested a reduction in the offset line distance,
defined in proposed S5.2.1(b), if the agency chooses to include gasket
material in measuring the daylight opening. Honda did not suggest a
value, but TRW recommended a reduction from 25 mm to 20 mm. No data
were provided to indicate that the 5 mm reduction would compensate for
reduction in the size of the opening that would occur from inclusion of
the gasket material. There could still be a risk that measuring the
size of the opening with gasket material in place could artificially
reduce the testable area in a manner not in the best interest of
safety. Given our decision to exclude the gasket material, we are not
reducing the offset line distance.
On the other hand, we do believe that a small change in the
definition of side daylight opening is necessary as it relates to
gasket material and weather stripping. The NPRM referred to ``flexible
gasket material or weather strip[p]ing used to create a waterproof seal
between the glazing and the vehicle interior.'' During our research, it
became apparent that gasket material, in addition to sealing the
glazing, may also provide a weather-tight seal between the door and the
door frame. For purposes of defining the window opening, this gasket
material should be treated the same as gasket material used for sealing
glazing, because if it were not, it could artificially reduce the size
of the daylight opening. Accordingly, S3 in this final rule excludes
flexible gasket material or weather stripping used to create a
waterproof seal between the glazing and the vehicle interior and the
door and the door frame from the definition of daylight opening.
iv. Testing With Flexible Gasket Material In Place
In the section above, we stated that the final rule will continue
to define the daylight opening without considering flexible gasket
material or weather stripping. Thus, this material may, on some
vehicles, need to be temporarily removed. However, this does not mean
that the testing will be performed without this material. The NPRM
proposed that the headform test be conducted with the flexible gasket
material or weather stripping in place.\125\
---------------------------------------------------------------------------

\125\ 74 FR 63205
---------------------------------------------------------------------------

The air bag suppliers commenting on this issue supported testing
with weather stripping. TRW stated ``the weather stripping must be
present to provide representative inflatable countermeasure deployment,
and occupant interaction with the countermeasure. Further, the absence
of weather stripping during the test, could expose edges which could
damage the countermeasure, affecting test performance.'' Takata stated
that they ``agree with the NHTSA's proposal to determine the target
location and carry out the testing with [the gasket] materials.''
As indicate in the previous section, most commenters wishing to
include gasket material or weather stripping in defining the daylight
opening were concerned about potential test problems associated with
removal and reinstallation. We have not experienced difficulty or
complexity in dealing with the gasket material in our testing. It has
been our experience that gasket material, due to its flexible nature,
can be moved aside to allow access to the vehicle surfaces that create
the daylight opening. If the gasket covers the relevant vehicle surface
that defines the daylight opening and needs to be removed temporarily
to allow access to that area, once the measurement is made removal of
the gasket need not be done again to define the opening. No data was
submitted to indicate such a single removal and reinstallation or, for
that matter, multiple removals and reinstallations, would have any
effect on test results. We do not believe that removing and
reinstalling the gasket will have any notable effect relative to other
factors influencing test variability, such as normal manufacturer
build-to-build variability.
We also agree with commenters who suggest that testing without this
material may unnecessarily expose the air bag to sharp surfaces. In
addition, the agency prefers to test a vehicle in as near the as-
manufactured condition as practicable. Thus, in the final rule we have
not added any regulatory text that indicates that flexible gasket or
weather stripping will be removed during testing, as we have done in
S6.3 for other parts of the vehicle.
v. Metal Dividers in Glazing
Hyundai requested clarification on how potentially non-structural
steel dividing elements in a window opening should be handled. Our
answer is such elements would serve to define the daylight opening
since they do not consist of glazing. We currently have no reasonable
way to exclude these dividing elements based on the extent to which
they may or may not add structural integrity to the vehicle.
2. How We Determine Impactor Target Locations In An Objective And
Repeatable Manner
i. Testing in ``Any'' Location
The Alliance, AIAM, Honda, Hyundai, AORC, TRW and Takata all
requested that the final rule maintain defined locations for the impact
targets as opposed to allowing any point in the window opening to be
targeted. The Alliance AIAM, Honda, and Hyundai suggested that testing
at any target point in the window opening would increase the testing
burden for manufacturers without providing any meaningful information,
and would introduce uncertainty in the certification process. The
Alliance stated that ``[t]he proposed up to 4 targets (without `target
reconstitution') achieves NHTSA's stated goal to `assess how well the
curtain covers the perimeter of the window opening' (FR 63204).''
(Emphasis in text). AORC stated that ``four impact points per window
opening sufficiently represents the `worse case' * * * .'' TRW also
agreed with the view that the NPRM ``adequately cover[s] the window
opening by requiring that the most demanding locations of the opening
be tested.'' Honda stated, in reference to

[[Page 3268]]

target points such as A1, that ``coverage of these most challenging
points by FMVSS No. 226 will successfully provide ejection mitigation
with the adoption of this regulation.'' Both TRW and Takata suggested
that the specification of exact target points supports a high level of
repeatability, reproducibility and robustness of testing. In contrast,
Advocates stated that the fixed target method limits the areas to be
tested and performance outside of those areas will not be known.
Agency Response
We have decided to use the methodology of the NPRM to define the
target points. First, we agree with the Alliance that the procedure
using four defined targets achieves the agency's goal of assessing the
coverage of the ejection mitigation countermeasure. We also agree with
Honda's comment that the fixed target method will test or come very
close to testing the worst case locations.
In response to Advocates, in developing the final rule's test
procedure, we sought to achieve a full and robust assessment of side
window opening coverage. We intentionally selected target locations
that we believed will provide the greatest challenge to the ejection
countermeasure. Based on our test data to date, we remain confident
that this is the case with our current target selection method. If we
were to test at any location, manufacturers will have less certainty in
the certification process. Whether this would result in increased test
burden is not clear. Although the concept of testing the window opening
at any potential impact point has merit, we do not believe it is
necessary for this standard to reduce certainty, since testing at
defined target points will achieve our safety objectives.
ii. Methodology
The Alliance believed that the target locations should be
determined in a manner consistent with the methods utilized by GM and
Ford, which are based on occupant seating positions and ``up and out''
occupant kinematics in rollover events. The Alliance stated that GM
uses three target points per window adjacent to a row of seating: (1)
Upper rear; (2) centroid of window opening; and (3) head position of
5th percentile female with the seat back at a 10-degree rearward
incline from vertical and the head position projected forward 30
degrees to the lateral axis. The Alliance indicated that, contrary to
what was stated by the agency in the NPRM, for some vehicles, the lower
forward GM target does not align with position A1. It stated that Ford
uses three in the front window and two in the rear windows. Ford's
front window locations are the same as GM's except that the target
corresponding to the 5th percentile female position is projected
forward from the lateral axis at 15 degrees rather than 30 degrees. For
rear windows, Ford eliminates the 5th percentile female head target
location.
The Alliance also requested that the rear window targets be
reversed, i.e., the mirror image from that proposed by the agency. It
stated that this would provide a ``more consistent protocol'' because
the front window and rear window targets would be located in the same
way, while achieving the stated goal of assessing ``how well the
curtain covers the perimeter of the windows opening.''
The Alliance disagreed with the proposed method to add back a
target (reconstitution). It believed that ``[t]he combination of FMVSS
214 and FMVSS 226 requirements renders testing at any point and `target
reconstitution' unnecessary and redundant to provide enhanced side
curtain coverage.''
Batzer and Ziejewski indicated that ``two impacts against the upper
half of the glazing should be adequate.'' The commenter stated that for
the bottom half of the window, the use of a headform is inappropriate.
The commenter stated that known occupant danger for this region of the
glass is arm and leg excursion and suggested that ``a new device that
simulates a forearm or calf/foot can, and should, be developed to
validate the side curtain airbag against this mode of excursion. This
need not be a 10 mph impact, but merely an excursion test.''
Agency Response
The agency has decided not to reduce the number of target locations
as requested by the Alliance and Batzer and Ziejewski. As expressed in
Honda's comment, coverage of the most challenging points like A1 are
necessary for FMVSS No. 226 to successfully ensure that adequate
ejection mitigation is provided. The same level of ejection mitigation
performance is not assured by the suggested alternative procedures.
We believe that three target locations are insufficient (and more
so for the two locations resulting from the Ford procedure for rear
windows) to test the entire perimeter of the daylight opening. The
Alliance indicated that the GM and Ford target points are consistent
with the assumption of ``up and out'' rollover occupant
kinematics.\126\ However, such an assumption ignores the possibility
that during long duration, multiple quarter-turn rollovers, occupants
can move to openings after impacting the ejection countermeasure, and
impact the countermeasure multiple times. In addition, the GM and Ford
impact locations seem to be most relevant to the belted occupant
situations. As we have stated many times, the bulk of the benefits of
this final rule come from unbelted occupants. The suggestion of Batzer
and Ziejewski for two impacts near the upper part of the window is not
well defined. It is not clear to us if the commenter is requesting two
impact locations or two impacts on the same countermeasure. The latter
would only be possible for a glazing-only countermeasure. If it is the
former, it is unsatisfactory for the same reasons that we have
expressed about the Ford procedure. We know from our own testing of
vehicle systems that testing point A1 is vital to determine if the
countermeasure provides full and robust coverage.
---------------------------------------------------------------------------

\126\ The commenter did not define the meaning of ``up and
out.'' Based on the context of the Alliance's use of the ``up and
out'' terminology, we assume that the term means that occupants
would be ejected near their longitudinal vehicle location at the
time of the rollover.
---------------------------------------------------------------------------

We are also declining the Alliance request to modify the target
locations for rear windows such that they are the reverse of that
proposed in the NPRM for rear windows. In Figure 13 below, illustrating
the suggested Alliance targeting, it is shown that the Alliance
procedure targeting can provide a large gap for daylight openings with
a forward rake. It is our experience that, to the extent that the rear
windows have a rake, this rake is forward. For rear window openings,
matching the front window pattern creates a large gap of coverage, as
shown in Figure 13. Further, the Alliance methodology crowds the
targets closer together, raising the potential for forcing the
elimination of targets based on the target reduction methodology. We
are not aware of any reason why it is important to have consistency
between the protocol used in the front and rear windows. Accordingly,
we are denying the Alliance and Batzer and Ziejewski requests.

[[Page 3269]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.019

iii. Reorienting the Targets
The Alliance, Hyundai, AORC, TRW, NTEA and Pilkington were all
opposed to reorienting the impactor headform.\127\ The Alliance stated
that ``[if a daylight opening is such that the headform cannot fit with
25 mm clearance when oriented with a vertical long axis, then NHTSA's
goal to reduce the risk of head and upper torso ejection has already
been achieved by the architectural characteristics of the vehicle,
particularly when combined with belt usage.''
---------------------------------------------------------------------------

\127\ This is the same as saying they did not want to rotate the
targets, because the impactor headform orientation is aligned with
the target orientation.
---------------------------------------------------------------------------

Hyundai stated that they ``found that the side daylight opening of
some vehicles with high belt-lines \128\ could not fit the outline of
the impactor headform within the 25 millimeter offset line of the
window opening.'' \129\ Nonetheless, Hyundai opposed the rotation of
the headform by 90 degrees for windows with small vertical dimensions
where no targets will fit with the typical impactor orientations. It
stated ``these windows are unlikely exit portals.'' TRW believed that
``revising the orientation of the headform for certain window shapes,
while not doing so for others, does not appear to be based on any real
world rationale.'' The Alliance, AORC and TRW raised testing concerns
related to reorienting the impactor. The Alliance stated: ``Arbitrary
deviations from [the NPRM] approach introduce unnecessary setup
variation and also increase the complexity of the impactor design.''
---------------------------------------------------------------------------

\128\ The beltline of a vehicle is a term used in vehicle design
and styling referring to the nominally horizontal imaginary line
below the side glazing of a vehicle, which separates the glazing
area from the lower body.
\129\ NHTSA-2009-0183-0044, p. 6.
---------------------------------------------------------------------------

The agency has decided that the final rule will allow the
reorientation of the targets and the associated reorientation of the
impactor headform, under specific conditions. We believe that, all
things being equal, the size of an uncovered side window has some
correlation to the risk of ejection. A gap in coverage of a small
window could be an ejection portal, just as it could be for a large
window. If the test procedure in the final rule does not allow for
rotation of the headform, it could allow large gaps in the window
coverage that could provide an ejection portal.
We examined two issues in investigating whether the headform should
be reoriented. The first issue involved reviewing the number and
location of impact targets for vehicles with relatively long and narrow
side daylight openings (high beltline vehicles) under the NPRM
targeting procedure. The second issue involved the pluses and minuses
of systematically rotating the target outline in small increments in
order to fit a single target in a window opening that would otherwise
not accommodate a target.
In an April 15, 2010 meeting with NHTSA, Ford showed the impact
locations for many of their current and future vehicles.\130\ One of
the vehicles was a MY 2010 Ford Taurus. In Table 40, we have summarized
the number of impact targets in each daylight opening for many of the
Ford vehicles, as provided by Ford.
---------------------------------------------------------------------------

\130\ Docket No. NHTSA-2009-0183-47.1

Table 40--Number of Targets per Daylight Opening for Ford Models, According to the NPRM Test Procedure
----------------------------------------------------------------------------------------------------------------
MY Model Type Row 1 Row 2 Row 3
----------------------------------------------------------------------------------------------------------------
2010............................ Taurus............. PC................ 1 1 NA
2010............................ Lincoln MKS........ PC................ 2 2 NA
2010............................ Lincoln MKT........ SUV............... 2 4 NA
2010............................ F150 Crew Cab...... PU................ 4 4 NA
2010............................ F150 Super Cab..... PU................ 4 2 NA
2010............................ F150 Regular Cab... PU................ 4 NA NA
2010............................ Flex............... SUV............... 4 4 4
2010............................ Mustang............ PC................ 3 0 NA
2011............................ Fiesta............. PC................ 3 2 NA
2012............................ Focus.............. PC................ 2 2 NA
2012............................ Future SUV......... SUV............... 3 3 NA
Next Gen. Full Size Van............... 4 4 4
Van.
----------------------------------------------------------------------------------------------------------------

This table indicates that, without target rotation, more than half
[\7/12\] of the vehicles on the list would have fewer than four targets
in the row 1 windows. Similarly, for the second row windows, seven of
11 would have fewer

[[Page 3270]]

than four targets. This level of target reduction is much greater than
we have seen in our research testing. There are several potential
reasons for this emerging picture. First, manufacturers initially
focused their introduction of rollover curtains on SUVs and pickups,
which typically have larger windows. Second, the trend towards higher
beltlines has reduced the height of windows.
The question then becomes, how extensive is the window opening
coverage for windows with fewer than four vertically oriented targets?
To help answer this question we also examined a partial side view of a
MY 2010 Chevrolet Camaro. This view is shown in the technical report
for this final rule. In Figure 14 below, we drew the outline of the
daylight opening and the associated 25 mm offset line for illustration
purposes. (These are approximations given the resolution of the image
and given that we did not know the dimensions of the flexible gasket
material around the opening. Also, we could not determine the exact
outline at the forward lower corner because the view was obscured by
the outside mirror. However, to the extent this drawing differs from
the actual image of the vehicle, the differences would not be
significant for the purposes of discussion in this section.)
If the targeting procedure defined in the NPRM is followed, the
four initial target locations (primary and secondary targets) are as
shown in the top graphic in Figure 14. (The procedure is explained in
detail in the NPRM at 74 FR at 63205-63211.) Under the NPRM procedure,
if the horizontal distance between target centers is less than 135 mm
and the vertical distance between target centers is less than 170 mm,
the targets are considered to be significantly overlapping and are
eliminated. At the end of the process, only a single target would
remain. See middle graphic of Figure 14(b). The forward edge of this
target is 464 mm from the forward edge of the daylight opening outline,
which would leave a large opening forward of the target untested.
Occupant ejection could occur through that opening. Further, if the
daylight opening were less than 1 mm smaller (a vertical dimension of
less than 276.1 mm), under the NPRM procedure, there would be no
targets in the window opening.
If we perform the same targeting procedure as defined in the NPRM
except with a horizontally-oriented target outline (the long axis
oriented horizontally), the result is the four targets shown in the
bottom graphic of Figure 14. The forward edge of the most forward
target was 173 mm from the forward edge of the daylight opening.

[[Page 3271]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.020

It appears that, if the target outline were to be kept only
vertical, there would be an artifact in the test that could result in
the exclusion of entire or large parts of some window openings from
being tested, while not excluding a window that differed only by a few
millimeters in dimension. For a long narrow window, the number of
targets can jump from zero to four with an increase in vertical
dimension of the window opening of only about 15 mm. If a long, narrow
window had a vertical dimension of 277 mm, the NPRM procedure would
result in no targets on the window opening. If the window vertical
dimension were increased by only 5 percent, from 277 mm to 290 mm,
under the NPRM procedure the targets would go from zero to four.
Figure 15 shows the result of the NPRM's targeting process with the
vertical dimension of the daylight opening increased by 3 percent (from
277 mm to 285 mm). The four initial vertical target locations are shown
in the top graphic. The target elimination process results in the two
middle targets being removed but under the target reconstitution
process a target is reconstituted between them; the final number of
vertical targets is three, as shown in the middle graphic of the
figure. The forward edge of the most forward target is 348 mm from the
forward edge of the daylight opening, which is a substantial area. If
we perform the targeting procedure with a horizontally oriented target
outline, the four targets shown in the bottom graphic of Figure 15
result. The forward edge of the most forward target is 159 mm from the
forward edge of the daylight opening.
BILLING CODE 4910-59-P

[[Page 3272]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.021

Figure 16 compares the horizontal coverage (dimension from leading
edge of most forward target to the trailing edge of the most rearward
target) of the daylight opening using the vertical and horizontal
target outlines. The vertical targets show a great deal of sensitivity
to the height of the daylight opening as opposed to the horizontal
targets, which are very insensitive to opening height.

[[Page 3273]]

[GRAPHIC] [TIFF OMITTED] TR19JA11.022

The second issue we explored involved the pluses and minuses of
systematically rotating the target outline in small increments in order
to fit a single target in a window opening that would otherwise not
accommodate a target. Figure 17 depicts a daylight opening that is too
small to fit a vertically oriented target outline within the offset
line. Under the NPRM targeting procedure, such a daylight opening would
not be impacted. However, rotating the target in increments of 5
degrees, from the initial vertical orientation, we find that the target
outline will fit at an angle of 45 degrees.
[GRAPHIC] [TIFF OMITTED] TR19JA11.023

We disagree with the Hyundai comment that suggested that, if there
are no vertically oriented targets that can fit in a window under the
NPRM procedure, it is unlikely to be a portal for ejection. We have no
data that supports the view that occupants maintain a vertical
orientation when ejected through a window in a rollover. Given the
chaotic nature of rollovers, we do not expect this to be the case. We
know of no convincing reason why the target should not be rotated at
the window opening, given that a simple and small rotation will enable
us to test a countermeasure in a satisfactory manner and ensure that
the ejection mitigation device fully covers the window opening.
If we specified that the targets may be reoriented (rotated) in a
systematic manner, we could eliminate an artifact in the proposed
procedure. In the section above, we saw that for a long

[[Page 3274]]

narrow window, the number of targets can jump from zero to four with an
increase in vertical dimension of the window opening of about 15 mm.
This is not desirable that a daylight opening would go from zero to 4
targets when the vertical dimension of the opening is above or below
276.1 mm. These artifacts of the combination of the window opening
geometry and the orientation of the impactor under the NPRM are
unacceptable, given that the standard would not assess the ability of
the countermeasure installed at the window opening to prevent partial
or complete ejections.
Contrary to the Alliance comments that rotating the headform is an
``[a]bitrary deviation'' of the test procedure, the agency believes
that, for certain situations, to leave the headform in the vertical
orientation would result in arbitrary results, not consistent with the
need for daylight opening coverage. Similarly, we disagree with the TRW
comment that implied that target reorientation needlessly complicates
the test procedure. Rotating the target outlines would add little if
any complexity to the standard. To the extent the procedure is more
complicated, the need is justified.
Accordingly, the agency has decided that this final rule will allow
the reorientation of the targets and the associated reorientation of
the impactor headform, under specific conditions. The conditions are
discussed below.
From the examples shown in the technical analysis above, any
situation where fewer than four vertical targets can be placed in the
daylight opening would allow for unacceptably large gaps in coverage.
As shown in Figure 15, supra, the 3 vertically-oriented targets had 279
mm less horizontal window coverage than did the 4 horizontally oriented
targets and the forwardmost horizontal target was 189 mm more forward
than the vertical target.
Yet, the agency has chosen not to change the orientation of the
impactor from vertical to horizontal when the same number of targets
can be placed in the daylight opening in either orientation. This is so
even though in some cases, it is possible that the horizontal targets
provide more horizontal coverage of the window opening. There are
several reasons for this decision.
First, regardless of target orientation, if the same number of
targets can be placed within the window opening then the area being
impacted in both cases would be essentially the same. For example,
looking at Figure 18 below, the target outlines impact approximately
the same amount of area in the window opening. What differs is the
distribution of the targets within the opening, which is solely a
function of the opening shape. The horizontal targets cover more of the
window opening towards the bottom of the A-pillar and the vertical
targets more fully cover more of the remaining areas of the window.
[GRAPHIC] [TIFF OMITTED] TR19JA11.024

[[Page 3275]]

Second, the bulk of our test data to date and the test data
submitted by comments are with the impactor in the vertical
orientation. This includes data that indicates that the proposed
requirements are practicable. Without more test data with a horizontal
orientation, we are reluctant to change the impactor orientation for
all window openings. Notwithstanding that most of our testing was done
with the impactor in the vertical orientation, when the number of
targets is fewer because the target is oriented vertically, we believe
that the importance of fuller window opening coverage outweighs all
other considerations.
Third, there are window openings that would otherwise not
accommodate a target unless the target outline is rotated to some
oblique angle. See Figure 17. We find it objectionable not to specify
that the impactor may be rotated.
We find no reasonable argument that would compel us not to allow
rotation of the impactor beyond the vertical or horizontal
configurations given that this might result in such a window not being
covered by any countermeasure. To say that an occupant's head or some
other body part cannot reorient itself during the rollover event,
including the head or body part of a belted occupant, is not logical.
The conditions for the rotation of the targets and impactor
headform by 90 degrees to a horizontal orientation are specified in the
final rule regulatory text at S5.2.5.2 and S5.6.2, respectively. The
conditions for the incremental 5 degree rotation of the targets and
impactor headform are specified in final rule regulatory text S5.2.5.3
and S5.6.3, respectively. The 5 degree increment reorientation is about
the y axis of the target and achieved by rotating the target's positive
z axis toward the vehicle's positive x axis.\131\ At each increment of
rotation, an attempt is made to fit the target within the offset line
of the side daylight opening. At the first increment of rotation where
the target will fit, the target is placed such that its center is as
close as possible to the geometric center of the side daylight opening.
---------------------------------------------------------------------------

\131\ Looking at the left side of the vehicle from the outside,
the rotation is counterclockwise and looking at the right side of
the vehicle, the rotation is clockwise.
---------------------------------------------------------------------------

iv. Suppose Even by Rotating the Headform the Vehicle Has No Target
Locations
AIAM and VSC requested that the regulatory text expressly state
that vehicles without any target locations are excluded from the
standard. Hyundai suggested that any window not having targets
according to the proposed requirement should be excluded.
Agency Response
We have added text to S4.2 of the standard to state that if a side
daylight opening contains no target locations, the impact test is not
performed on that opening.
The vehicle is not excluded from FMVSS No. 226, however. There are
a number of requirements in section S4.2 of the standard that apply to
vehicles that have an ejection mitigation countermeasure that deploys
in the event of a rollover. Paragraph S4.2.2 requires the vehicles to
have a monitoring system with a readiness indicator meeting certain
specifications. Paragraph S4.2.3 requires the vehicle owner's manual to
have written information about the ejection mitigation system and the
readiness indicator. Paragraph S4.2.4 requires the manufacturer of the
vehicle to make available to the agency, upon request, certain
information about the rollover sensor system. Vehicles that have an
ejection mitigation countermeasure that deploys in the event of a
rollover are subject to these requirements even if side daylight
openings contain no target locations. Since the vehicle is subject to
FMVSS No. 226, the vehicle may be counted as a vehicle that meets the
ejection mitigation requirements of the standard for phase-in and
advanced credit purposes.
v. Decision Not To Test Target of Greatest Displacement
Vehicle manufacturers were supportive of a method to reduce the
number of tests. However, not all supported the alternative presented
in the NPRM to test at the 24 km/h impact speed at only the target
location with the greatest displacement during the 16 km/h impact.
Hyundai stated that ``no significant additional information would be
gained by testing all of the lesser displacement locations.'' The
Alliance alternatively suggested a single impact speed and time delay
for all target locations (16 km/h with a 3.4 second delay). The
Alliance opined that ``[d]eployment of side curtain airbags is highly
dependent on placement of garnish trim and performance of attachments
in the vehicle body. If a subsequent test needs to be performed [on]
one side of a vehicle after an airbag is deployed, a new airbag and new
garnish trim will have to be installed.'' \132\ They mentioned that
this reinstallation may not be representative of factory installation.
In addition, it alleges that attachment points may wear or deform after
multiple tests.
---------------------------------------------------------------------------

\132\ NHTSA-2009-0183-0029, p. 30.
---------------------------------------------------------------------------

AIAM stated that ``[t]here would be no reduction in test burden
unless the agency were to require manufacturers to identify which
impact location had the largest displacement in their low speed
certification testing, so that the agency could perform its high speed
test at the same location. Otherwise, the manufacturer could be
required to conduct high speed tests at all impactor locations, to
assure that it has test data for the same location that the agency
tests.''
Air bag suppliers were mixed in their responses on this topic. TRW
recommended ``keeping all four impact tests at both impact speeds. This
is because NHTSA testing could identify a different `worst point' than
is identified by the OEM in their tests. Therefore, vehicle
manufacturers would likely need to test more extensively than NHTSA.
Thus while the compliance testing burden may be slightly lowered,
testing at the manufacturer [sic] will probably not be diminished
significantly.'' Takata suggested the alternative of testing all target
locations at the 24 km/h-1.5 second test, then performing the 16 km/h-6
second test only at the location experiencing the greatest displacement
in the first series. Takata believed that ``it is important to test all
the locations at the high energy level to ensure structural integrity
of the countermeasure device. This approach identifies a robust design
and also reduces the number of tests.''
Agency Response
After considering the comments, we have determined that the final
rule will require that all target locations be impacted at the higher
and lower impact velocities rather than just impacting one target
location at the higher speed test. This adopts the regulatory text
option presented in proposed S5.5(2A) (except, as discussed earlier in
this preamble, the higher speed will be 20 km/h rather than 24 km/h).
We found the comments from AIAM, TRW, and Takata to be informative
and persuasive. We agree with AIAM and TRW that there is unlikely to be
a significant reduction of test burden to the industry by only
requiring a 1.5 second-high speed test at the location that yields the
greatest displacement at the 6 second-low speed test. This is because
our ejection mitigation side air curtain test data indicates that there
is typically no clear distinction between the displacements of several
of the target points in a vehicle window

[[Page 3276]]

opening. There sometimes is no clear distinction that a certain target
is the ``weakest,'' showing the most displacement in the 16 km/h-6
second test. Agency testing of production vehicles set forth earlier in
this preamble indicates that the weakest target location is not obvious
across data from the 24 km/h-1.5 second test, 20 km/h-1.5 second test,
or the 16 km/h-6 second test. Based on limited data from our new
impactor, we found that there is less difference in displacement
between the 20 km/h-1.5 second and 16 km/h-6 second tests. (See rank of
the displacement by target location for the second row testing of the
MY 2008 Highlander, Tables 10-18, supra.) Thus, vehicle manufacturers
might not be assured from their data which target location will be the
weakest in a NHTSA test. Accordingly, they may end up testing all of
the targets to all of the impact speeds.
We also agree with Takata's comments that all target locations must
be tested at the higher impact speed to assure that the testing
determines the robustness of the designs. However, not only must the
robustness of design be assessed at the top impact speed of 20 km/h,
performance at 6 seconds must also be determined. The agency can only
assure this by impacting all locations at 16 km/h with a 6 second
delay.
AORC suggested that the standard could specify that manufacturers
will pronounce to us which target point should be tested at the higher
speed. We do not agree with the logic of binding the agency to only
impact target locations deemed by the manufacturer to have the greatest
displacement in the 16 km/h test. Such an approach would be an
unacceptable limitation of the agency's ability to independently
determine how to test a vehicle.
We also did not find compelling the comments expressed by the
Alliance. We have already discussed and rejected the commenter's
suggestion that FMVSS No. 226 should have only a single impact speed
and time delay for all target locations (16 km/h with a 3.4 second
delay).
With regard to the commenter's suggestion that there should be only
one 16 km/h test due to wear and tear on and effect of trim components
on testing, we decline this suggestion also. There was no showing that
issues related to trim components justify reducing the tests to a
single impact speed. Moreover, the Alliance's concerns about trim
components appear inconsistent with Nissan's comment. Nissan indicated
that it would like the final rule to allow testing on an untrimmed
``cut body'' and that the headliner would not be expected to affect
performance of the side curtain air bag system. This indicates to us
the possibility that trim components generally might not have a
significant effect on curtain performance. The Alliance's comments
about trim components are not substantiated and do not justify reducing
the number of tests to one.
This final rule does reduce a test burden on manufacturers of
vehicles that use only non-movable (fixed) glazing as the ejection
mitigation countermeasure to meet FMVSS No. 226, without use of a
deployable ejection mitigation countermeasure. We have written the
standard to apply only the 20 km/h-1.5 second test to the daylight
opening with the non-movable glazing, and not the 16 km/h-6 second
test. If the displacement limit can be met at the window opening in the
20 km/h-1.5 second test, we will not subject the window opening to the
16 km/h-6 second test. This is because the 20 km/h test would be
redundant. If the displacement limit is met in the high speed test, we
believe the limit will be met in the low speed test.
vi. Reconstitution of Targets
The Alliance disagreed with the proposed method to add back a
target (reconstitution). It believed that ``[t]he combination of FMVSS
214 and FMVSS 226 requirements renders testing at any point and `target
reconstitution' unnecessary and redundant to provide enhanced side
curtain coverage.''
Agency Response
We disagree with the Alliance's position that target reconstitution
is unnecessary and redundant. A large space between two impact
locations in a daylight opening is not consistent with our desire for
full window coverage. Reconstituting (adding back) a target back
between two distantly-spaced targets helps to meet our goal. We note
that both the Ford and GM internal ejection test procedures have an
impact location at the geometric center of the window. For many window
shapes assessed under the procedures of this final rule, the target at
the center of the window would be close to the location that would be
covered by the middle target reconstituted. Thus, the Ford and GM
procedures appear to recognize the merits of testing for full window
coverage.

f. Glazing Issues

The NPRM proposed to allow movable windows made from advanced
glazing to be in position (up and closed) for the compliance test, but
pre-broken by a specified test procedure to simulate the breakage of
glazing during a rollover. Tempered (non-advanced) glazing shatters
when broken, so for tempered glazing, we proposed that we would conduct
the glazing breaking procedure and shatter the glazing, remove the
glazing, or retract the glazing, at the manufacturer's option.
1. Positioning the Glazing
The NPRM discussed the pros and cons of advanced glazing for
ejection mitigation. Advanced glazing may enhance the performance of
current air bag curtain designs. Vehicles tested by NHTSA showed an
average displacement reduction across target locations and test types
of 51 mm.\133\ However, the updated target population data show that 31
percent of front seat ejections and 28 percent of all target population
ejections are through windows that were partially or fully open prior
to the crash. Further, the agency was concerned that in the real world,
advanced glazing would not be as effective as an ejection
countermeasure due to vehicle structural deformation and the effects of
inertial loading of the window mass.
---------------------------------------------------------------------------

\133\ We stated in the NPRM that we believed that incorporation
of advanced glazing for ejection mitigation would be relatively
expensive compared to the implementation of air bags. The PRIA
showed that the proposed requirements would add about $33 per light
vehicle at a total cost of $568 million for the full curtain
countermeasure. A partial curtain plus advanced glazing would have
an incremental and total cost of $88 and $1,494 million,
respectively.
---------------------------------------------------------------------------

The NPRM requested comments on several alternatives, including the
alternative of testing all movable windows removed or retracted,
regardless of whether the window is laminated or tempered; fixed
laminated windows would be permitted to be kept in place, but pre-
broken.
Comments
Commenters were divided in their views of how Standard No. 226
should test vehicles that have advanced glazing covering a side
daylight opening.
Vehicle manufacturers and air bag suppliers did not support testing
with advanced glazing in place. Ford stated that ``[s]ide glazing
retention, regardless of construction-type (e.g., laminated or
tempered), in real-world rollover crashes is random and
unpredictable.'' Ford stated that side glazing retention ``is dependent
on the unique characteristics of that particular crash (e.g., number of
quarter turns, vehicle roll rate and deceleration, objects contacted,
occupant loading, vehicle deformations, etc.).'' The commenter

[[Page 3277]]

referred to an SAE paper from Kramer, et al.\134\ in which the authors
stated ``there is information from the field (FARS and other individual
collisions) that document ejections through laminated side glass.''
Ford recommended \135\ that--
---------------------------------------------------------------------------

\134\ Kramer et al. ``A Comparative Study of Automotive Side
Window Occupant Containment Characteristics for Tempered and
Laminated Glass,'' SAE Paper 2006-01-1492.
\135\ NHTSA-2009-0183-0020, p. 4.

the eventual requirements of FMVSS 226 be focused on rollover
activated side curtain technology, with consideration of the
associated capabilities of this technology, because these devices
are designed to deploy regardless of side glazing status in a
rollover (e.g., retained, up, down or partially open) or
---------------------------------------------------------------------------
construction of the glazing.

Honda had a similar view, stating that ``a vehicle with movable
windows, being operated with a laminated glazing even partially open,
could result in the window falling out of the window frame due to body
deformation resulting from the crash or subsequent ground contact
during a rollover event.'' It stated that because the pre-breaking
procedure allows the window to be in the full up position it ``may not
fully simulate real world conditions.'' Honda suggested that all
testing should be done with the windows ``removed or retracted prior to
the impact test instead of allowing pre-breaking for movable windows.''
For fixed laminated windows, the commenter said that ``the concerns
mentioned above would not apply and pre-breaking would be a suitable
method of simulating real world conditions * * *.''
AORC and TRW expressed concerns about testing glazing with the
window up. They suggested that the agency could test without any
glazing present, but either increase the amount of allowable excursion,
or reduce the energy level (i.e. reduce the impactor velocity) for
impact locations which have advanced glazing, to reflect the enhanced
performance expected if the advanced glazing were present.
In contrast, glazing suppliers stated that all testing should be
performed with the advanced glazing in place because they believed that
the NPRM provided strong support of advanced glazing in reducing
impactor displacement.
Consumer groups overall supported the use of advanced glazing. IIHS
described roof crush and side impact testing it did on several vehicles
with front row laminated glazing. IIHS stated that all the laminated
glazing remained intact within the window frame. IIHS suggested NHTSA
provide an incentive to vehicle manufacturers to use advanced glazing,
such as by testing all vehicles without the glazing in place but allow
a higher displacement for vehicles equipped with laminated glazing. In
contrast, Advocates suggested NHTSA should test with both air curtains
and advanced glazing and require a much reduced displacement limit.
Public Citizen wanted the final rule to specifically disallow the use
of advanced glazing on a vehicle unless it was in combination with side
curtain air bags. Public Citizen stated there is a lack of evidence
that laminated glazing will perform well enough on its own.
Agency Response
This final rule does not allow the use of movable glazing as the
sole means of meeting the displacement limit of the standard (i.e.,
movable glazing is not permitted to be used without a side curtain air
bag). It also specifies that if a vehicle has movable advanced glazing,
the 16 km/h-6 second test will be performed with the glazing retracted
or removed from the daylight opening. Our decision is based on the
following factors.
First, field data already evidence an incongruity between the
glazing countermeasure and the foreseeable use of it by the public. The
updated target population data show that 31 percent of front seat
ejections and 28 percent of all target population ejections are through
windows that were partially or fully open prior to the crash. We have
no small concerns about a countermeasure that can be easily, totally
and most likely unknowingly counteracted by motorists by the simple and
everyday act of opening a window. As crash data show, many in the
target population already operate their vehicles in a manner that
negates the efficacy of the countermeasure. Any benefits accruing from
advanced glazing will not be achieved if the window were partially or
fully down.
Second, in contrast to IIHS's roof crush and side impact laboratory
test findings, the field data of real-world performance of advanced
glazing are showing that even when movable advanced glazing is
initially up, such glazing may not be present as an effective
countermeasure beyond the initial phase of a rollover. Rollovers are
one of the most severe and unpredictable vehicle crash events. Based on
an analysis of field data and the comments on the NPRM, we are not
confident at this time that movable advanced glazing used alone,
without an ejection mitigation side air curtain to supplement it, will
be a viable countermeasure throughout a rollover crash. The following
illustrates some real world examples of the un-predictable nature of
advanced glazing in rollovers.
In NASS CDS case 2001-43-190, a MY 2000 Audi A8 experienced a left
leading, four quarter-turn rollover.\136\ This vehicle did not have
side curtain air bags. The unbelted driver was completely ejected
through the sunroof. The belted front passenger was not ejected. The
technical report accompanying this final rule shows the interior views
of the passenger and driver sides of the vehicle, respectively. The
passenger side laminated glazing has completely detached from the first
and second row windows. However, the first and second row driver side
windows are in place. The first row driver side window was coded as
being partially open prior the crash. It remained so after the crash,
although it was extensively damaged. The second row driver side window
was in place and undamaged.
---------------------------------------------------------------------------

\136\ Although the NASS coding indicates that the first 2 rows
of side windows were tempered glass, we determined this to be
incorrect from the photographic evidence.
---------------------------------------------------------------------------

In SCI case CA09063 (RODSS 7242), a MY 2003 Lincoln Aviator with
laminated glass in the driver's side window sustained a head-on
collision followed by a three quarter-turn rollover. This vehicle had
rollover deployable curtain air bags, but they did not deploy. The
driver and right front passenger were belted. There were no ejections.
Both laminated driver and front row passenger windows detached from the
window opening.
In SCI Case CA10006 (RODSS 8289), a MY 2003 Lincoln Aviator
experienced an eight quarter-turn rollover. This vehicle had rollover
deployable curtain air bags, which deployed. The driver and right front
passenger were belted. The belted driver was killed due to partial
ejection of her head. Both laminated driver and front row passenger
windows vacated the window opening. The passenger side window glazing
is shown in the foreground of a photograph of the scene, completely
detached from the vehicle.
In these examples, it is not possible from the visual evidence to
determine when in the rollover event the advanced glazing detached from
the window opening, nor the cause(s) of the separation. In all except
one of the cases there was a belted occupant adjacent to the window
that detached from its opening. In these cases, occupant interaction
may have been a factor. The rear passenger side window of the Audi did
not have an adjacent occupant, so

[[Page 3278]]

occupant contact was not likely the cause of the window vacating the
opening. Other potential causes are structural deformation and inertial
forces due to impact or vehicle rotation.
We found compelling the Ford and Honda comments discussing the
potential for advanced glazing to detach from the window opening in
real-world rollovers. We agree with Ford that the retention of advanced
glazing, particularly movable glazing, can be a function of the random
and unpredictable nature of rollovers. We also believe there is merit
to the Honda contentions that movable advanced glazing could vacate the
window frame due to vehicle body deformation resulting from crash
dynamics or ground contact, even when the window is partially up, and
that the pre-breaking procedure performed in a full-up position may not
fully simulate these conditions. We found their comments to be
consistent with the information presented above, which shows examples
of field performance of advanced glazing (specifically laminated
glazing) in several rollover and combination crashes (rollover in
combination with planar impacts). Particularly interesting is the Audi
A8 rollover, where the glazing on one side of the vehicle vacated, but
the windows on the other side did not.
Ejection is a major cause of death and injury in rollover crashes.
As stated in our discussion of the safety need for this rulemaking,
according to 2000-2009 FARS data, about half of the occupants killed in
rollovers were completely ejected from their vehicle. A double-pair
comparison from the last ten years of FARS data show that avoiding
complete ejection is associated with a 64 percent decrease in the risk
of death. The ejection countermeasures that should be installed in
response to this final rule are those which have been shown to perform
well in keeping occupants in the vehicle in rollover crashes. We are
unable, at this time, to assert our confidence in the ability of
advanced glazing to retain occupants throughout a multiple quarter-turn
rollover when used alone in movable window applications.
We have learned from the comments about ways to improve FMVSS No.
226's ability to distinguish between countermeasures. We saw that the
test procedure should be enhanced to ensure that the vehicle will
provide ejection mitigation protection throughout a multiple quarter-
turn real-world rollover. The proposed impactor test of ejection
countermeasures is appropriate and worthwhile, but we have learned that
to better replicate real-world conditions, it is imperative to remove
any kind of glazing on a movable window when preparing for the 16 km/h-
6 second test. Since there is a reasonable possibility that the movable
window glazing will vacate the vehicle in the later stages of the
crash, by removing the glazing in the test we better replicate the
real-world condition. Removing such glazing, and expressly stating in
the standard that vehicles are not allowed to use movable glazing as
the sole means of complying with the standard, assure that movable
advanced glazing will be used with an ejection mitigation side curtain
air bag or other deployable safety system. These provisions assure that
the movable glazing will have to be supplemented by a side curtain air
bag or other countermeasure, thus assuring a minimal level of safety in
the event the window is partially or fully rolled down or vacates the
window opening due to the dynamics of the crash.
It is possible that there could be modifications to the designs of
the window frame that may improve the ability of movable advanced
glazing to remain within the window opening during a rollover.\137\
However, the agency currently does not have the information to make
this determination. We assume that this is what the AORC meant when it
stated that a single integrity test for laminated glazing could be
established to verify retention. Unfortunately, we did not learn of
these potential test parameters from the comments.
---------------------------------------------------------------------------

\137\ The agency researched such window frame modifications
during the research into advanced glazing as a standalone ejection
mitigation countermeasure. ``Ejection Mitigation Using Advanced
Glazings: A Status Report,'' November 1995, DOT DMS NHTSA-1996-1782-
3, pp. 4-7 to 4-10. Results indicated that adequate retention was
maintained in the area of encapsulation, but that the unsupported
(nonencapsulated) top edge was subject to large deflections. (pg. 7-
29).
---------------------------------------------------------------------------

Some glazing manufacturers indicated that the problem of the open
window could be mitigated by newer vehicle safety technology that rolls
windows up prior to a crash. It is our understanding that at least some
of these systems are initiated when the ESC is activated.\138\ ESC
would activate in only a portion of the rollover events that make up
our target population, i.e., most likely single vehicle rollover
crashes. The remainder would not be covered. Moreover, the
effectiveness, cost and practicability of an automatic roll up system
in achieving the benefits of ejection mitigation throughout a multiple
quarter-turn rollover has not been demonstrated.
---------------------------------------------------------------------------

\138\ Mercedes offers this feature and calls it Pre-Safe.
---------------------------------------------------------------------------

Accordingly, for the 16 km/h-6 second test, if a vehicle has
movable advanced glazing as all or part of the ejection countermeasure,
the test will be performed with the glazing retracted or removed from
the daylight opening. Based on the 28 percent of the target population
ejected through windows open prior to the crash and uncertainties about
the field performance of the current movable advanced glazing, we
cannot agree to the request that all impact testing be performed with
the movable advanced glazing in place.
If the advanced glazing is fixed in place, we will not remove it in
the 16 km/h-6 second test. It is reasonable to assume that glazing
permanently fixed in the up position will be up when the vehicle is on
the road. We will pre-break the fixed glazing, to replicate the state
of the glazing during the stages of a rollover event, but we will not
remove it. Likewise, if the glazing is fixed, we will pre-break it but
will not remove it in the 20 km/h-1.5 second test. Thus, it remains
technically possible under the standard to have fixed advanced glazing
as the standalone countermeasure. This provides an incentive to
manufacturers to use advanced glazing.
Movable advanced glazing will not be removed in the 20 km/h-1.5
second test. This test will be performed with the advanced glazing in
place, but the glazing will be pre-broken to replicate the state of the
glazing at the outset of a rollover event. Although advanced glazing
could vacate the opening late in the crash event after many quarter-
turns, we have more confidence that advanced glazing will not be
dislodged early in the rollover event represented by the 20 km/h-1.5
second test. This is because vehicle structural deformation and
inertial effects resulting from ground contacts contributing to glazing
being dislodge will be cumulative, i.e., increase as the rollover event
continues.
IIHS's tests also showed that the advanced glazing on some of the
vehicles it tested remained within the frame in roof crush and side
impact testing. Allowing movable advanced glazing to be in position in
the high speed (20 km/h-1.5 second) test will provide an incentive to
vehicle manufacturers to use advanced glazing to meet the standard's
requirements or enhance ejection mitigation performance of side
curtains.
We decline the suggestions to provide an incentive for advanced
glazing by increasing or decreasing the allowable displacement of 100
mm. TRW and AORC suggested increasing the allowed

[[Page 3279]]

displacement, or decreasing the impact speed, at places on the window
opening that had advanced glazing. We cannot agree to lessen the
severity of the test for advanced glazing as this would reduce the
protection of the motorists, particularly those who may have the window
partially or fully rolled down. Advocates suggested decreasing the
displacement limit below 100 mm for combined advanced glazing plus
curtain air bag. As explained earlier in this preamble, the 100 mm
limit strikes the appropriate balance between stringency and
practicability.
Advocates also stated that vehicle structural deformation will
reduce the effectiveness of the curtain air bags and advanced glazing
will increase roof strength.\139\ It presented no data to substantiate
these claims. NHTSA is not aware of a technical or engineering basis
for the view that side curtain air bag performance will be reduced by
structural deformation.
---------------------------------------------------------------------------

\139\ The relevance of the Advocates comment about advanced
glazing increasing roof strength is not clear to us. In the May 12,
2009, FMVSS No. 216 final rule, the agency stated that we had
investigated the contribution of tempered side windows to roof
strength and found that it had limited effect (74 FR 22371). We have
no reason to believe that there would not be similar results from
advanced laminates.
---------------------------------------------------------------------------

Our concerns about the performance of advanced glazing also extend
to the deformation of the window opening. Because of its mass, advanced
glazing will be much more susceptible to inertial loading from vehicle
rotation and vehicle ground contact than will curtain air bags. That
was the point of our statement in the NPRM (74 FR at 63213) about
advanced glazing having greater mass compared to an air bag curtain. In
response to comments from some glazing suppliers, we did not mean to
imply that laminates had a weight penalty when compared to tempered
glazing.
2. Window Pre-Breaking Specification and Method
We have determined that there is a safety need to have a glazing
breaking procedure applied to both the interior and exterior sides of
the glazing. We are slightly modifying the proposed procedure, to adopt
use of a 75 mm offset pattern to reduce the glazing preparation time.
NPRM
In the NPRM, we proposed specifications and a method that called
for punching holes in the glazing in a 50 mm horizontal and vertical
matrix (``50 mm matrix'') on both sides of the glazing. A spring-loaded
automatic center punch was to be used to make the holes. The punch has
approximately a 5 mm diameter before coming to a point. The spring on
the punch was adjusted such that 150 N 25 N of force \140\
was required for activation. The details of the procedure were
described in the NPRM. When punching a hole, we placed a 100 mm by 100
mm piece of plywood on the opposite side of the glazing as a reaction
surface against the punch. In testing glazing that will disintegrate
under the procedure (e.g., tempered glazing), the vehicle manufacturer
could opt to remove or completely retract the tempered glazing and
thereby bypass the window breaking process.
---------------------------------------------------------------------------

\140\ This force level worked well for the samples of advanced
glazing tested by the agency.
---------------------------------------------------------------------------

We also noted that we would be continuing research into window pre-
breaking methods, specifically, a variation of the 50 mm matrix hole
punch method where the holes on either side of the glass are offset by
25 mm. Initial indications at the time of the NPRM were that this
variation exhibits the potentially positive attribute of lessening the
chances of penetrating the inner membrane between the glass layers. 74
FR at 63215.
Comments
The Alliance said that use of different punches and punch settings
can produce differing amounts of penetration and potential damage to
the plastic laminate. The commenter also believed that the tolerance
for the punch activation force is too large (17% of nominal value), and
that the ``rigid'' backing material needs to be specified, as does the
pressure/force applied to the backing material. The AORC supported
offsetting the breaking pattern by 25 millimeters from the inside to
the outside of the window, to reduce the potential that a punch
impacting the same point from both sides of the window would produce a
hole through the laminate. Guardian, EPGAA and Solutia believed that
the 50 mm pre-breakage procedure was excessive and not consistent with
real-world conditions, particularly breakage of the interior side of
the glazing. Guardian commented that at a minimum the pre-breaking
procedure be altered to offset the punch locations on either side of
the glazing. Exatec asked about the suitability of the procedure for
non-glass advanced glazing material.
Agency Response
We disagree with the comments from the vehicle manufacturers and
air bag suppliers that the proposed pre-breaking procedure was too time
consuming, onerous, or impractical. Nonetheless, the procedure we adopt
today calls for less than half the number of punched holes, reducing
the glazing preparation time.
We have performed well over 100 tests with advanced laminated
glazing using various methods of pre-breaking. About 30 of these tests
have been performed using a 50 mm matrix. We estimate that it takes our
laboratory technicians about 30 minutes to mark the 50 mm grid pattern
and punch all the holes for a relatively large front row side window.
The time it takes to mark the holes per glazing pane can be
significantly shortened by laying an unmarked pane on top of an already
marked pane. If a subsequent test is to be performed (as might be the
case during research and development) and the door trim is installed,
it takes approximately 20 to 60 minutes to replace the glazing. Often
this is done in parallel with preparations for other aspects of the
test, so the overall test time is not affected appreciably. This
procedure is not difficult or onerous to conduct.\141\
---------------------------------------------------------------------------

\141\ When testing with tempered glass, if the glass pane does
not move completely out of the window opening into the door, it must
be removed by opening the door trim. This glass pane removal takes
about 20 to 60 minutes as well, due to the removal and
reinstallation of door trim.
---------------------------------------------------------------------------

Nor is the procedure gratuitous. To the contrary, the pre-breakage
procedure is crucial to ensuring that advanced glazing will perform as
intended in the field. Advanced glazing is weakened when pre-broken;
the more breakage of the glazing, generally the more displacement of
the impactor. See Table 23 of the NPRM, 74 FR at 63215. The pre-
breakage procedure is intended to condition the glazing to mimic the
degree of breakage that is occurring in the field. Crash information
and the results of impact testing corroborate the necessity of the
proposed procedure.
In the technical report accompanying this final rule, we have
images from several rollover crashes. The first was a MY 2000 Audi A8
that underwent four quarter-turns. The second was a MY 2003 Lincoln
Aviator that was exposed to a frontal impact followed by a three
quarter-turn rollover. The last vehicle was also a 2003 Aviator that
experienced an eight quarter-turn rollover. The technical report also
shows a close-up of the driver side window laminated glazing of the
Aviator that rolled eight quarter-turns. In all of the cases, the crash
scene photographs show the degree to which both sides of the glazing
have been disintegrated, especially for those laminates that have
vacated the window

[[Page 3280]]

opening. This finding that advanced glazing experienced severe damage
to both inside and outside surfaces and detached from the vehicle
supports our belief that pre-breaking the advanced laminate should be
aggressive. The technical report also has a view of the driver's
advanced glazing in a 2000 Audi A8 from NASS case 2001-43-190. The
glazing remained in the window. Some areas appear more highly damaged
than others.
Accordingly, we are adopting the glazing breaking procedure, with
slight changes that reduce the number of punched holes.
In the NPRM preamble (74 FR at 63215), we stated that that the
agency was contemplating using a method for glazing pre-breaking that
takes the 50 mm matrix and offsets the holes horizontally on each side
of the glazing by 25 mm. Initial indications were that this variation
exhibits the potentially positive attribute of lessening the chances of
penetrating the inner membrane between the glass layers. Our research
since the NPRM has been focused on this and another alternative offset
method. This alternative uses a 75 mm by 75 mm hole punch pattern on
both sides of the glazing. However, the matrix on the inside of the
glazing is offset by 37.5 mm [75 mm/2] horizontally. A 75 mm matrix
pattern is used to reduce the number of breakage points from the 50 mm
matrix, and as stated before, the offset reduces the chances of
completely penetrating the material sandwiched between the glazing
layers. The technical report provides a schematic of the 50 and 75 mm
offset patterns.
Our new results are consistent with our previous results. See the
technical report for this final rule. We found that the method of pre-
breaking the laminated window has a discernable effect on the test
results. We compared the 50 mm offset pattern to the 75 mm offset
pattern. When these treatments were able to be compared statistically,
there were no significant differences between the 50 and 75 mm offset
hole punch pattern as it relates to impactor displacement. Moreover,
given that finding and the finding that the 75 mm offset has less than
half the number of punched holes, reducing the glazing preparation
time, this final rule adopts the use of the 75 mm offset pattern.
In response to Exatec, the final rule will clarify that it is only
necessary to attempt to make the holes in the glazing and to not
actually succeed. However, we will not change the procedure to stop
after the first row is attempted. We have no firm basis at this time to
treat one type of advanced glazing any differently than another. It is
conceivable that the punches might not break the material, but could
produce stress concentrations that weaken it.
Finally, we decline all but one of the Alliance's requests because
we do not believe that the procedure is not repeatable or reproducible
and no information to the contrary was provided by the commenter. We
believe that the tolerances and values for center punch angle,
activation force and punch tip diameter are sufficient. We will
specifically call out the material for the 100 mm x 100 mm reaction
surface, rather than simply indicate that it should be rigid. The final
rule will specify the use of plywood with a minimum thickness of 18 mm
(standard \3/4\ inch), which is the material we used during our
testing. Although we believe any sufficiently rigid material will
adequately perform this function, for simplicity we will specify
plywood.

g. Test Procedure Tolerances

The proposed regulatory text had tolerances on various test
parameters of the proposed test procedure. For example, the proposed
text specified that the target outline must be aligned within 1 degree of the vehicle longitudinal plane when determining the
proper target location. Tolerances were selected such that they would
not affect the test results, yet not be so small as to be unusable. In
some instances, we based tolerances on those of other FMVSSs because
those tolerances have been practicable and useful. For example, the
tolerance on the impactor alignment with the vehicle lateral axis was
based on a similar linear impactor tolerance in S5.2.5(c) of FMVSS No.
202a, ``Head Restraints.'' Tolerance selection was based on test
experience and engineering judgment. Comments were requested on whether
the tolerances assure an objective, repeatable and practical test
procedure.
Comments
1. The Alliance ``requested that impactor specification be updated
to clarify that the long axis of the impactor headform is to maintain a
vertical orientation throughout the full stroke of the impact event.
This approach is recommended in an effort to maximize repeatability and
reproducibility of test results.'' The Alliance stated that they had
observed some impactors that constrain this motion and others that do
not.
Agency Response
We agree with the request. The headform should not be able to
freely rotate during the impact test. Both our original and new test
devices have a specific mechanism to constrain them from rotation about
their axis of travel. Thus, we have added a specification that the
ejection impactor is inspected after the test, to make sure that it is
still within the 1 degree tolerance required at launch.
2. TRW and AORC expressed concern about the 0.1 second
tolerance on the impact times of 1.5 and 6 seconds. They suggested a
tolerance of 0.05 seconds to reduce the amount of test
variability due to air bag pressure changes. The AORC also would like
the agency to clarify the time delay such that it would be the period
of time the ``unimpeded impactor would arrive at the target location.''
Agency Response
We are declining these requests. To answer the questions, it is
important to keep in mind that under the test procedures, the impactor
is to strike the countermeasure at the specified speeds and time
delays.
The target location is found by projecting the daylight opening on
a vehicle vertical longitudinal plane and then projecting the target
onto that plane. There are an infinite number of parallel vertical
longitudinal planes, or alternatively, the vertical longitudinal plane
can be thought of as having any lateral location. Assembling all the
planes, each with a projection of the target, creates a three
dimensional projection of the target, which crosses the vehicle
laterally. Or, in other words, imagine the 2 dimensional target being
translated along the transverse vehicle axis, creating a path the
impactor headform should be setup to travel along.
If the countermeasure is an air bag, it is deployed, and the
ejection impactor is to strike the countermeasure (air bag) at the
impact target location, at the specified speed and time delay. The
trigger for the time delay is the activation of the countermeasure. For
a curtain air bag, that would be the time at which the deployment is
activated. The speed and time of impact of the impactor are measured at
contact with the countermeasure (air bag) and must both be within the
specified tolerances. To make it clear that it is the countermeasure
that must be contacted at the specified time intervals, we have added
text to S5.5(a).
Since the agency anticipates that its tests will involve testing
side curtain air bags, we need to account for the effect of the air bag
on the impactor's timing. The calibration testing of our new impactor
indicates that the impactor would meet the timing tolerance

[[Page 3281]]

reduction recommended by commenters if the target were at a static
location. However, although our experience has been that curtain air
bags deploy in a very consistent and repeatable manner, the fact is
they are not static. Also, we determine contact time on a curtain
through video analysis. All in all, because of the variables and
calculations needed to establish contact time with the countermeasure,
we believe it is more reasonable to maintain the 0.1
second impact time tolerance.
3. The AORC suggests the procedure specify that contact with the
countermeasure occurs when the impactor is beyond the influence of the
propulsion system.
Agency Response
We agree and have modified S5.5 of the regulatory text by adding a
statement that the specified ejection impactor velocities must be
achieved after propulsion has ceased.
4. Honda asked if the agency has any intention of specifying the
interval between each impact test. It also stated that the impactor
speed might decrease after propulsion, so it requested that ``NHTSA
clarify the position (by time) that the impact speed should be
measured.'' Honda also asked how contact with the countermeasure is
determined, and requested that we clearly state the speed and
displacement measurement methods. Honda further requested that NHTSA
provide the accuracy, sampling time, and filtering of each sensor.
Agency Response
We do not agree with the suggestion to specify an interval between
multiple tests. We do not know of a reason to rest the equipment
between tests. We have no reason to believe that the amount of time
between tests would have any effect on the test results.
As explained above in answering TRW and AORC, the speed and time of
impact are measured at contact with the countermeasure and must both be
within the specified tolerances. We have made these measurements during
our research testing, in several ways. As indicated above, one method
we have used to determine time of contact within a resolution of about
5 ms is video analysis. Another method is to know prior to the test the
approximate location of the impactor stroke where contact will occur.
In either case, the velocity versus time output of the ejection
impactor can then be used to determine if the contact time and velocity
parameters were met.
There is no need to provide in the standard a specification for
velocity and displacement measurement. There are multiple ways of
measuring impactor displacement and velocity. The output of
displacement-based instruments such as Linear Variable Differential
Transformers (LVDTs) or string potentiometers can be used directly for
displacement or differentiated to give velocity. Accelerometer output
can be integrated once for velocity and twice for displacement. A
light-based speed trap can be used for velocity measurement as well.
The agency has used all of these methods. We believe it would be
counterproductive to specify a single method in the regulatory text in
that this may limit our flexibility in conducting compliance testing.
We note also that we found that our new impactor loses very little
speed over large ranges of stroke. If the speed is correctly set, it is
not difficult to meet the 0.5 km/h speed tolerance.

h. Impactor Test Device Characteristics

The agency proposed certain characteristics that the impactor
should be calibrated to meet in order to enhance the repeatability of
the test, i.e., to increase the likelihood that the headform will be
delivered to the countermeasure and interact with it in a repeatable
manner. One was a 20 mm limit on static deflection when the impactor is
loaded by a 27 kg mass. There were two specifications to limit the
amount of energy the impactor may lose due to friction. The proposal
specified that the ejection impactor must not lose more than 10 and 15
percent of the 24 and 16 km/h impact velocity, respectively, in 300 mm
of unobstructed dynamic travel. Second, it must not require more than
an average of 570 N of force to push the impactor rearward with a 27 kg
mass attached to it. Finally, we required that impactor be able to
deliver the center of the headform through a theoretical cylindrical
shape.
The agency stated that the research test device used to develop the
proposal had not been optimized for compliance test purposes (74 FR at
63216, footnote 81.). Thus, we stated our belief that tighter
tolerances on the calibration characteristics could be attained with an
optimized design. Id. Nonetheless, the agency's impactor was found to
meet the percentage velocity reduction, on an average basis.
Comments
Honda asked that the agency indicate in the regulatory text where
the static deflection of the impactor headform should be measured. With
respect to the targeting accuracy requirement, Honda wanted to know
``if it is necessary to verify accuracy of the actual contact position
after each impact test, as long as the test device satisfies the
specifications.'' It stated that with testing of an air bag it would
not seem to be possible to verify whether the targeting accuracy was
achieved during the test. Also with respect to this targeting accuracy
requirement, it wished to have the agency specify a calibration method.
TRW believed that the performance attributes of the impactor are
adequately covered by the AORC impactor specifications, as presented at
the 2009 SAE Government/Industry meeting. These specifications are
provided below in Table 41, for the convenience of the reader.
---------------------------------------------------------------------------

\142\ Stein, Doug, ``Linear Impactor Performance Characteristics
for Ejection Mitigation Testing,'' SAE Government/Industry Meeting,
February 6, 2009, Washington DC. File Impactor--Charaterization.ppt,
available at http://www.aorc.org/coep.asp.

Table 41--AORC Recommendations for Impactor Performance 142
------------------------------------------------------------------------
Preliminary
Variable Maximum variance recommendation
------------------------------------------------------------------------
Velocity........................ 0.75 0.25
km/h. km/h.
Deflection...................... >> 25 mm.......... < 10 mm.
Time Delay to Impact............ 400 ms............ < 100 mm (or
redefine time to
contact).
Excursion Accuracy.............. 4.6 2 mm.
mm.
Dynamic Friction................ 2.62.............. < 0.25.
Design Margin................... - 20% (TYP)....... TBD.
------------------------------------------------------------------------

[[Page 3282]]

The AORC commented that NHTSA should adopt similar specifications
for impactor performance as used by the agency in their solicitation
for a new impactor (Solicitation Number DTNH22-09-Q-00071).
The highlights of that solicitation are provided in the bullets
below. An asterisk notes that the solicitation requirement matches the
AORC recommendation.
The ejection mitigation impactor must be capable of
measuring the displacement of the moving impactor mechanism throughout
the entire stroke, with an accuracy of 2 mm.*
The maximum radial deflection of the ejection mitigation
impactor must not exceed 10 mm.*
When the ejection mitigation impactor assembly is used in
conjunction with the support frame, it must have a vertical radial
deflection of no more than 15 mm.
The maximum dynamic coefficient of friction of the
ejection mitigation impactor must not exceed 0.25.*
The moving impactor mechanism must be designed for use at
peak velocities between 15 km/h and 25 km/h, with a tolerance within
the range of 0.25 km/h; a range of 0.15 km/h or
less is preferred.*
When used with an appropriate propulsion system, the time
from the signal to deploy the air curtain to the peak velocity of the
moving impactor mechanism (minus any pre-programmed delay time) must
not exceed 100 milliseconds for any velocity within the range of 15 km/
h to 25 km/h. These velocities must also be achieved prior to the
impactor making contact with deployed air curtains of current
production.*
When the headform is fired at 24 km/h, point P must remain
within cylinder C from the position at which the moving impactor
mechanism achieves peak velocity to the position 100 millimeters beyond
the position of peak velocity. Point P is the geometric center of the
headform on the outer surface of the headform, and cylinder C is a 20-
millimeter diameter cylinder, centered on point P and parallel to the
headform's direction of motion.
Agency Response
Many provisions of the impactor test device calibration have been
modified to make them consistent with some of the calibration
procedures suggested by AORC and others. The static deflection
provision has been changed from 20 mm under a 27 kg load, to 20 mm
under a 981 N force applied in four orthogonal directions, with the
device in a test-ready configuration. The final rule will require a
limit on the dynamic coefficient of 0.25, measured in four orientations
with the shaft loaded with a 100 kg mass. We believe this provision
will fulfill the requirement previously specified by the unobstructed
velocity test and obstructed push force tests.
In response to Honda, we have added text to S7.2 in the final rule
to indicate that the movement of the ejection impactor targeting point
in the x-z plane (vehicle vertical-longitudinal plane) should be
measured. In other words, looking along the y axis (direction of
travel), the center of the headform face should not deflect more than
the specified value. We have also added additional detail to this
section to indicate that this static deflection test is to be performed
with the impactor attached to the propulsion mechanism, including any
support frame connecting it to the floor. In addition, the force is now
applied in four orthogonal directions, rather than just downward. This
is an acknowledgement that loading on the impactor can be in any
direction.
Since the test is performed on the device in a test-ready
configuration, the allowable displacement is 20 mm rather than the 10
mm recommended by the AORC in Table 41. The 10 mm value would be more
appropriate for a test that excludes the supporting frame of the test
device, as did the AORC recommendation.
There is no reason to specify the displacement measurement accuracy
for the impactor since we will use a method sufficiently accurate to
determine that the displacement limit has been exceeded or not. There
is also no reason to specify a minimum time from launch until the
impact speed is obtained; how long it takes the impactor is irrelevant
to the test as long as it arrives at the specified delay times of 1.5
0.1 seconds and 6.0 0.1 seconds.
A very important impactor characteristic is dynamic friction. We
have indicated in S7.3 of the standard that the dynamic friction must
not exceed 0.25. This matches the AORC recommendation. In the technical
report for this final rule, we provided these dynamic friction
measurements for the agency's new impactor and how the agency
determined dynamic friction characteristics.
We note that the dynamic friction test differs from the static
deflection test in that it need not be done on the support frame that
would connect to the impactor in a test-ready configuration. We believe
this is acceptable since it is not likely that the static deflection of
the entire frame will influence the dynamic friction determination. We
also think it is acceptable that the perpendicular loading for the
dynamic friction testing is achieved through gravity and rotation of
the impactor and bearings rather than by pulling in four orthogonal
directions, as is done in the static deflection tests. Practically
speaking, there is no other way to perform the test.
We believe that this detailed dynamic friction test in S7.3 of the
standard will fulfill the purpose of the requirements previously
specified in the NPRM for unobstructed velocity (proposed S7.2.1) and
obstructed push force (proposed S7.2.2). We have reduced the maximum
allowable dynamic coefficient of friction of the test device by a
factor of 5 from 1.29 (NPRM) to 0.25 (final rule). In addition, S7.2.1
allowed as much as a 15 percent velocity loss over a range of impactor
stroke. Testing of the new impactor found about a 1 percent loss in
impactor speed over a stroke of more than 150 mm. Thus, we conclude
that proposed S7.2.1 can be removed with no negative effect on the test
procedure.
We understood Honda's comments on the issue of targeting accuracy
(see S7.4 in the final rule) as seeking clarification as to when the
accuracy is to be determined, i.e., would the tester need to know that
for any particular impact test the ejection impactor targeting point
was within the required cylindrical targeting zone shown in Figure 16
of the NPRM. The answer to Honda's question is provided in S7 of the
standard, where it is stated: ``[t]he ability of a test device to meet
these specifications may be determined outside of the vehicle.'' That
is, it is necessary that the test device being used meet the
characteristics in S7, but these need not and cannot be determined
during the test. We cannot see that it would be feasible to perform
these calibration measurements during a vehicle test. Honda requested
the agency specify how often and/or when these calibration tests should
be done. We cannot make such a pronouncement in the regulatory text.
Frequency of calibration is a test device and due care-specific issue
and must be determined case by case.
Honda also wanted to know how targeting accuracy would be measured
by the agency. On our new impactor, we made this determination through
analysis of high speed video. We found that the impactor met the
required accuracy. We can envision other measurement techniques that
utilize witness marks on stationary targets, or that make witness marks
on the headform.

i. Readiness Indicator

NHTSA proposed a requirement for a monitoring system with a
readiness

[[Page 3283]]

indicator for ejection mitigation systems that deploy in a rollover,
such as that required for frontal air bags in S4.5.2 of FMVSS No. 208.
74 FR at 63218.
No comments were received opposing the proposal. Accordingly, the
proposal is adopted for the reasons discussed in the NPRM.

j. Other Issues

1. Rollover Sensors
The NPRM did not require vehicle manufacturers to provide a sensor
that deploys the ejection countermeasure in a rollover or side impact
crash, and did not dictate the performance of any supplied sensor. We
were concerned as to whether specifying performance features for the
sensor could satisfactorily capture the myriad of rollovers occurring
in the real-world. Moreover, we explained that ejection mitigation air
bag curtains are now being designed, developed, and implemented by
industry and are deploying satisfactorily in the field.
We believed there would be no incentive for manufacturers to
provide an ejection mitigation side curtain designed to meet the
standard without providing the sensor to deploy it in a rollover crash.
In addition, under the proposed requirements of the standard,
manufacturers would be required to provide written information to
NHTSA, upon the agency's request, explaining the basic operational
characteristics of their rollover sensor system. We also proposed to
deploy the side curtain in our compliance testing only if the owner's
manual or other written material informs the owner that the vehicle is
equipped with an ejection mitigation countermeasure that deploys in the
event of a rollover.
The NPRM also discussed alternatives considered by the agency to
the approach proposed, such as requiring that the rollover sensors be
provided as a piece of equipment and defining such a piece of
equipment, or specifying a test that would assure the presence of a
rollover sensor on the vehicle. Advantages and disadvantages of the
approaches were presented.
Comments
Nearly all comments from vehicle manufacturers and air bag
suppliers supported the NPRM's not establishing specific rollover
sensor requirements or performance tests. The Alliance concurred with
the NPRM that sensors are performing well in the field. GM stated its
support for only deploying air bags ``during the compliance test that
have been identified in the owner's manual as rollover-enabled. This is
a practicable and reasonable approach.'' GM agreed that manufacturers
would have no incentive to misidentify an air bag system as rollover
capable. AIAM stated that manufacturers have their own test and
calibration processes for crash sensors, so adding any tests in the
final rule would only add complexity to manufacturers' test plans for
little or no benefit. AIAM believed that the definition of sensor
deployment requirements is vehicle specific due to the different nature
of such factors as mass distribution, center of gravity height and use
of stability systems. Therefore, AIAM believed that setting a generic
test requirement would not be feasible.
On the other hand, Honda believed that ``some manner of performance
criteria may be necessary for rollover sensors required for deployment
of such countermeasures.'' The commenter encouraged NHTSA to establish
basic performance criteria ``consistent with other elements of the test
procedure for FMVSS No. 226, if possible.'' Honda suggested a
definition for ``rollover sensor'' and suggested that NHTSA ``establish
a minimum requirement for the system configuration.''
Advocates and Public Citizen requested that the final rule place
requirements on sensors that would deploy the ejection countermeasures
rather than leave it to the discretion of the manufacturer. Advocates
believed that NHTSA should specify requirements for sensors to ensure
sustained inflation throughout the long event of a rollover with
multiple quarter-turns. Public Citizen recommended a dynamic test that
``would allow the agency to measure both the presence and the
performance of rollover sensors.''
IIHS stated that while it understood the agency's reluctance to
specify performance requirements for sensors that may not capture the
scope of real-world rollover crash scenarios, NHTSA should continue
monitoring field data to determine the adequacy of the agency's
approach.
Agency Response
This final rule adopts the approach of the NPRM and does not
specify direct rollover sensor specifications. The agency is not aware
of any repeatable rollover test that replicates the breadth of real-
world rollovers addressed by this rulemaking. Current dynamic tests,
such as the 208 Dolly test, do not allow the agency to determine how
well the sensor will perform in the field. The 208 Dolly test offers
little challenge to the sensor and, according to Viano and
Parenteau,\143\ represents a very small portion of rollover crashes.
See the NPRM, 74 FR at 63218, for additional discussion of dynamic
rollover testing.
---------------------------------------------------------------------------

\143\ Viano D, Parenteau C., ``Rollover Crash Sensing and Safety
Overview,'' SAE 2004-01-0342.
---------------------------------------------------------------------------

With respect to Honda's comment on specification of ``some manner
of performance criteria'' and/or a definition for ``rollover sensor,''
this concept is very similar to an option discussed in the NPRM
preamble (Equipment Definition Option) (74 FR at 63218). We indicated
in that analysis that this option was problematic for several reasons.
We stated that such an option has the--

limitation of having to definitively specify the item of equipment
it would be requiring, which might necessitate adopting and applying
an overly restricted view of what a deployable rollover is and
perhaps what it is not. For example, we can contemplate rollovers
that have such an extremely slow roll rate when it would not be
necessary or desirable for the countermeasure to deploy. That being
the case, a reasonable definition of a rollover sensor might include
a roll rate specification as a function of roll angle. Developing
such a definition requires vehicle roll angle versus rate data,
which are not readily available to NHTSA. Another potential drawback
of this option is that without a test or tests to assess compliance
with the definition, enforcement of the requirement could be
restricted. An approach for a compliance test could be for NHTSA to
remove the sensor from the vehicle and subject the sensor to a
performance test to assess whether a specified performance
requirement is achieved, but the agency has limited information at
this time on which to develop performance parameters or a compliance
test.

Id.

As Honda's comments did not address the shortcomings of this
option, the agency continues to have concerns. We thus decline to
implement Honda's request in this final rule.
In view of the determination to adopt the approach of the NPRM, and
after reviewing the comments, we conclude that it is critical that
written information be provided in the owner's manual that describes
how the ejection mitigation countermeasure deploys in the event of a
rollover (see regulatory text of S4.2.3(a) of this final rule) \144\
and how

[[Page 3284]]

system readiness is monitored (see S4.2.3(b)). It is also important
that the test procedure not deploy the ejection countermeasure if this
information is not provided (see S5.5(c)). We also adopt the
requirement that the final rule require manufacturers to provide more
detailed technical information to the agency upon request (see S4.2.4).
---------------------------------------------------------------------------

\144\ Ford provided excerpts from the owner's manual of a
vehicle with a rollover curtain air bag, and asked if the
information would meet the requirements of S4.2.3(a), ``Written
information.'' (NHTSA-2009-0183-0047, p. 20.) Ford's excerpt stated
in part: ``The Safety Canopy system is designed to activate when the
vehicle sustains lateral deceleration sufficient to cause the side
crash sensor to close an electrical circuit that initiates Safety
Canopy inflation or when a certain likelihood of a rollover event is
detected by the rollover sensor.'' Our answer is yes.
---------------------------------------------------------------------------

Field data on vehicles with rollover sensors continue to indicate
that curtains are deploying in rollovers when they should. Of the 21
RODSS cases, four NASS cases and 48 SCI cases believed to involve
vehicle rollover crashes and presumed to have rollover deployable
curtains, five were determined not to have deployed.
We conducted an in-depth review of these five cases. Four of the
five cases had a significant frontal impact that preceded the rollover.
These impacts may have destroyed the vehicle battery and thus
eliminated the primary power source for deploying the rollover curtain.
There is also some question as to whether one of these vehicles was
definitely equipped with a rollover sensor, since the system was an
option on this vehicle. In one case, the vehicle's kinematics were very
complex and may have included some motion not typical of a lateral
rollover.
After reviewing the five non-deployment cases, it was not apparent
to us that there was a problem with the rollover sensor that would have
been identified by a test for a sensor, such as the Equipment
Definition test or Presence test discussed in the NPRM (74 FR at
63218). We cannot make a finding that in these cases, the rollover
curtains' non-deployment was unrelated to the initial frontal impacts.
A presence test that only addressed whether the curtain will deploy,
that did not account for a significant initial frontal impact, might
not have made any difference on the deployment of these rollover
curtains.
We have become interested, however, after reviewing the field data,
as to whether ejection mitigation systems could have a backup power
source, such as a capacitor, that can provide the power for curtain
deployment within some short time period after primary power is lost.
It is our understanding that generally vehicles currently have such
energy storage systems, but these systems may not have the ability to
deploy rollover curtains when the rollover is subsequent to a frontal
impact causing the loss of power. There were only a handful of cases on
hand. We would like to learn more about this issue.
We are not ready to specify in this final rule some sort of
requirement related to the ability to deploy the curtain after loss of
primary power. For one thing, we believe that this issue is outside of
the scope of notice of the NPRM. Moreover, NHTSA would like to gain
more knowledge in this area. We would like to analyze the vehicle
kinematics that result when a frontal crash is followed by a rollover
to better understand the amount of time secondary power is, and should
be, available. Data available from event data recorders may provide a
starting point for the analysis of this issue. We have begun a review
of the EDR data available to the agency and will continue to monitor
data as it becomes available. We would like to find out if there is a
problem in the field and seek to know more about the amount of storage
time capacitors typically have vis-[agrave]-vis their ability to deploy
the curtain after power is lost.
2. Quasi-Static Loading
We requested comments on the need for an additional test that would
impose quasi-static loading on the ejection countermeasure. Films of
occupant kinematics in vehicle rollover testing and in DRF testing
indicate that ejection mitigation countermeasures can be exposed to
quasi-static loading during a rollover, in addition to short-duration
impacts that the headform test replicates. Quasi-static loading can
occur when an occupant contacts the countermeasure and loads it
throughout or nearly throughout an entire rollover event.
Comments
AIAM commented that in the absence of data demonstrating that
countermeasures designed to meet the proposed requirements are not
adequate to address quasi-static loading, there is no basis for
adopting such a test requirement at this time.
Agency Response
We are not adopting a requirement at this time. Instead, we plan to
pursue some limited testing in the near term to see how an ejection
mitigation countermeasure that performs well to the requirements in the
final rule performs in a quasi-static test. At this time, there are no
data available to the agency. Therefore, we cannot determine the
consistency, or lack thereof, between quasi-static performance and
impact test performance.
3. Full Vehicle Test
The NPRM explained the agency's position that the component test of
FMVSS No. 226 would not only distinguish between acceptable and
unacceptable performance in side curtain air bags, but has advantages
over a full vehicle dynamic test. The acceptable (or poor) performance
in the laboratory test correlated to the acceptable (or poor)
performance in the dynamic test. The component test was able to reveal
deficiencies in window coverage of ejection mitigation curtains that
resulted in partial or full ejections in dynamic conditions.
Incorporating the component test into an ejection mitigation standard
would ensure that ejection mitigation countermeasures provide
sufficient coverage of the window opening for as long in the crash
event as the risk of ejection exists, which is a key component
contributing to the efficacy of the system.
The NPRM further noted that rollover crash tests can have an
undesirable amount of variability in vehicle and occupant kinematics.
In contrast, the repeatability of the component test has been shown to
be good. Moreover, there are many types of rollover crashes, and within
each crash type the vehicle speed and other parameters can vary widely.
A curb trip can be a very fast event with a relatively high lateral
acceleration. Soil and gravel trips have lower lateral accelerations
than a curb trip and lower initial roll rates. Fall-over rollovers are
the longest duration events, and it can be difficult to distinguish
between rollover and non-rollover events. Viano and Parenteau
correlated eight different tests to six rollover definitions from NASS-
CDS. Their analysis indicated that the types of rollovers occurring in
the real-world varied significantly. Soil trip rollovers accounted for
more than 47 percent of the rollovers in the field, while less than 1
percent of real-world rollovers were represented by the 208 Dolly test.
74 FR at 63185.
The NPRM also discussed our belief that occupant kinematics will
also vary with these crash types, resulting in different probabilities
of occupant contact on certain areas of the side window opening with
differing impact energies. Id. A single full vehicle rollover test
could narrowly focus on only certain types of rollover crashes
occurring in the field. We noted in the NPRM our concern that a
comprehensive assessment of ejection mitigation countermeasures through
full vehicle dynamic testing may only be possible if it were to involve
multiple crash scenarios. Such a suite of tests imposes test burdens
that could be lessened by a component test. We also noted that a
comprehensive suite of full-vehicle dynamic tests would likely involve
many more years of research, which would delay the rulemaking

[[Page 3285]]

action and the potential for incorporating life-saving technologies.
The agency stated that such a delay appears unwarranted, given that
NHTSA believes the component test will be an effective means of
determining the acceptability of ejection countermeasures.
Comments
AIAM agreed with the agency's view that a dynamic full vehicle test
should not be pursued at this time. The commenter concurred that it is
not clear how the agency could represent the wide range of rollover
crash scenarios with a single test mode, and that manufacturer
certification using a series of test modes would be unduly burdensome.
AIAM also stated, ``Making a dynamic rollover test adequately
repeatable for regulatory purposes would also be a very significant
challenge.'' AIAM supported continued research on developing a
practicable dynamic test approach that provides additional safety
benefits.
In contrast, Batzer and Ziejewski recommended that in addition to
an impact test, NHTSA should ``mandate that all manufacturers perform
at least one FMVSS-208 style dolly rollover test.'' Advocates believed
that the FMVSS No. 226 impact test does not account for ``door-window
frame distortion that can occur in rollover crashes'' and that this
could result in reduced curtain air bag effectiveness. Public Citizen
also supported a whole vehicle dynamic test. Public Citizen stated that
further delays needed to develop a dynamic test would ``benefit
occupants in rollover crashes, if a dynamic rollover test resulted in a
better standard that was more representative of real world crash
conditions.'' The commenter also stated that the agency ``cannot simply
add up the sum of the target populations identified in each of its
rollover rulemakings and claim to have protected occupants.''
Agency Response
For the reasons discussed in the NPRM, the final rule will not
contain a full vehicle dynamic test to evaluate ejection mitigation.
We understand the appeal of a dynamic test for ejection mitigation
as well as all aspects of rollover protection, a complement of sorts to
frontal and side protection offered by the dynamic tests in FMVSS Nos.
208 and 214, respectively. As a matter of fact, the agency is currently
pursuing a research program looking at the development of a dynamic
test to address roof strength. In addition, the agency has been
pursuing laboratory research on restraint system (e.g., seat belt
system) optimization for rollover crashes.
As it happens, however, a full vehicle dynamic test for rollover
crashworthiness systems is not available. An FMVSS No. 208 (frontal
impact) or No. 214 (side impact) test presents different challenges
than a rollover test. Frontal and side impacts, while deadly, are less
complex by comparison to a rollover crash. As explained in the NPRM,
rollover crash tests have a high degree of variability in vehicle and
occupant kinematics. There are many types of rollover crashes, and
within each crash type the vehicle speed, roll rate, roll axis and
other parameters can vary widely. In contrast, the critical parameters
for planar crashes can be captured by the direction of impact and
[Delta]V. It is a relatively simple matter to develop a test(s) (i.e.,
a vehicle into barrier or object into vehicle) that results in the
desired vehicle [Delta]V in the desired direction.
Nor might a full vehicle dynamic test be available as an outgrowth
of the agency's roof crush and seat belt system research. The vehicle
kinematics involved in assessing enhanced protection of the occupant
within the vehicle (studied in the roof crush and belt system programs)
may be significantly different from those involved in mitigating the
risks of occupant ejection to belted and unbelted occupants. A dynamic
test that is appropriate for assessing roof crush and seat belt
performance may not necessarily provide the same kind of challenge to
ejection mitigation.
It may or may not be suitable to have a single rollover test to
assess roof crush and seat belt performance. For ejection mitigation,
it is unlikely that a single rollover test would be sufficient to
address the many types of rollovers that occur in the field.\145\ We
would want the dynamic test to assure that an ejection mitigation
countermeasure constrains belted and unbelted occupants in all types of
rollover crashes. However, at this time there is no archetype rollover
crash that can be replicated in laboratory testing.\146\
---------------------------------------------------------------------------

\145\ We have already discussed our determination that the 208
Dolly test is not suitable for ejection mitigation testing. See,
e.g., 74 FR at 63185. The 208 Dolly test represents less than 1
percent of real-world rollovers. Further, some recent experience
with the 208 Dolly test makes problematic its implementation as a
replacement for the impact test or an additional test. During recent
tests in our rollover restraints research program, we attempted to
subject a MY 2007 Ford Expedition to the 208 Dolly procedure.
However, two out of five attempts failed to initiate a roll of even
one quarter-turn. We acknowledge that the above was not a typical
result of 208 Dolly testing within the agency's experience, but it
does highlight testing issues.
\146\ A full vehicle dynamic test would presumably involve the
use of anthropomorphic test devices (ATDs). There is some question
whether the currently available ATDs offer an acceptable level of
biofidelity with respect to occupant ejection. For example, the hip
articulation for the Hybrid III dummies is limited, which may alter
their ability to replicated real world occupant kinematics. An
appropriate ATD for use in the test would have to be explored.
---------------------------------------------------------------------------

We stated in the NPRM preamble, ``a comprehensive assessment of
ejection mitigation countermeasures through full vehicle dynamic
testing may only be possible if it were to involve multiple crash
scenarios. Such a suite of tests imposes test burdens that could be
assuaged by a component test such as that proposed today.'' 74 FR at
63186. We hope that in the future, a full vehicle dynamic test, or a
suite of tests, could be developed that is appropriate for use in FMVSS
No. 226. However, at this time, there is not a viable full vehicle
rollover test procedure to evaluate ejection mitigation. In response to
Public Citizen, we strongly disagree that a delay of this rulemaking to
develop a dynamic test would be justified. This final rule will save
over 370 lives a year. Each year delayed to develop what is now an
indefinable full vehicle test will have a substantial human cost.
Public Citizen also commented that the agency ``cannot simply add
up the sum of the target populations identified in each of its rollover
rulemakings and claim to have protected occupants.'' The agency takes
great care when doing the benefits assessment to not double count lives
saved. If we assume a specific population is saved by one of our
standards, we do not count them again when determining the benefits for
another. In this way, our estimates are conservative.
4. Minor Clarifications to the Proposed Regulatory Text
In preparing the final rule regulatory text, we made some changes
to make the text clearer and easier to understand. The changes were not
meant to alter the requirements of the proposal. Below we provide a
listing of the more noteworthy of these minor changes and a brief
rationale for the change.
S3. Ejection Impactor--Deleted ``It consists of an ejection
headform attached to a shaft'' and moved it to S7.1. This was done
because this descriptive information is consistent with the type of
information provided in S7.1.
S3. Ejection propulsion mechanism--Deleted ``specified in S7.2 of
this Standard No. 226.'' This was deleted because S7.2 (New S7.3) does
not really

[[Page 3286]]

provide information specific to the propulsion mechanism.
S3. Target Outline--Eliminated the term ``target outline'' and
replace it with ``target'' throughout the regulatory text. This does
not result in any substantive change in the standard, since in the NPRM
these terms were defined to be interchangeable in the regulatory text.
S3. Walk-in van--Deleted the second sentence indicating that the
seating position must be forward facing and edited the first sentence
to indicate the only seating position is the driver. This was done to
eliminate redundancy in the definition.
S4.1.1--Added text to the first sentence referencing S8. This was
done to provide clarity and similarity with other standards.
S5.1--The wording of the third sentence was modified to clarify
that the countermeasure was being struck at the defined target
locations.
New S5.2.1.1 (NPRM S5.2.1(a)), S5.5.5, S5.4.1.1--All occurrences of
``daylight opening'' were replaced with ``side daylight opening.''
New S5.2.1.1 (NPRM S5.2.1(a)), second sentences--Added the word
``projection'' after ``side daylight opening.''
New S5.2.2(a) (NPRM S5.2)--Deleted ``and the x-z plane of the
target outline within 1 degree of a vehicle vertical
longitudinal plane.'' This was a redundant constraint. However, text
was added to indicate that the y axis of the target points outboard.
New S5.2.3.3 (NPRM S5.2.2.3)--Revisions were made to the structure
of this section to clarify the determination of primary targets.
S5.5(a)--The sentence was modified to make it clear that it was the
countermeasure that must be impacted at the specified time.
S5.5(a) and (b)--Replaced ``velocity'' with ``speed.''
S6.1--Added text to clarify how the vehicle attitude is to be
adjusted.

k. Practicability

NHTSA believed that meeting the proposed requirements as they
applied to the side windows at the first three rows was practicable.
There were a number of vehicles with side air bag curtains that cover
the windows adjacent to rows 1, 2, and 3, such as the 2005-2007 MY
Honda Odyssey, 2006 Mercury Monterey, 2007 Chevrolet Tahoe, and 2007
Ford Expedition.\147\ The agency also believed it was practicable to
produce vehicles that would meet the proposed performance requirements.
---------------------------------------------------------------------------

\147\ Since that time the following vehicles with three rows of
coverage have been tested: MY 2007 Jeep Commander, MY 2008 Dodge
Caravan, MY 2008 Ford Taurus X, and MY 2008 Toyota Highlander.
---------------------------------------------------------------------------

The NPRM had a proposed 24 km/h-1.5 second test, which has been
reduced in this final rule to 20 km/h-1.5 second. Some of the current
production vehicles tested during the development of the NPRM came
close to meeting the 100 mm displacement limit at all target locations
and impact speeds. The most challenging target location was A1, with A4
being the least challenging. For the 2nd row windows, the limited data
indicated target location B1 was more challenging than B4. Only two
vehicles were tested at the 3rd row. For these systems, C4 was more
challenging than C1.
The agency stated that the primary parameters that determine the
stringency of the test were: (a) The impactor dimensions and mass; (b)
the displacement limit; (c) impactor speed and time of impact; and (d)
target locations. Comments focused on (c) above, specifically impactor
speed, to argue for reducing the stringency of the test based on
practicability grounds.
We discussed in an earlier section of this preamble our decision to
reduce the impactor speed from 24 km/h-1.5 second (400 J) to 20 km/h-
1.5 second (278 J), based on a reanalysis of the research data used for
the NPRM. We believe this reduction in test velocity resolves many of
the comments, described below, that raised concerns about the
practicability of meeting a 24 km/h-1.5 second test. However, we wish
to address the concerns about practicability to explore any remaining
questions about the practicability of meeting a 20 km/h-1.5 second
requirement. Further, we would like to discuss issues relating to the
practicability and cost of meeting a 24 km/h-1.5 second requirement.
Comments
All comments relating to practicability were submitted by vehicle
manufacturers. The comments were focused on side curtain air bags as
the sole countermeasure for the FMVSS No. 226 requirements. The
comments did not appear to dispute the potential of manufacturing side
curtain air bag systems that could meet the NPRM; rather they expressed
concerns with the potential negative trade-offs associated with such
systems for both side impact and OOP occupants.
Honda referred to agency statements in the NPRM that indicated that
two methods of improving the ejection mitigation performance of curtain
air bags were to make them thicker and to increase their internal
pressure. Honda provided data on the relationship between internal
pressure and impactor displacement. Honda argued that increasing tank
pressure of an air bag design to meet the proposed requirements (to
produce less displacement of the impactor) results in notable increases
in Nij and neck compression measures. Honda believed that if 200 J is
set as the impact energy limit (17 km/h impact), ``the primary
objective of the side curtain airbag of occupant protection can be
balanced with the proposal for occupant ejection mitigation without
significant change to current side curtain airbag designs for some
vehicles.''
VW also provided information showing the relationship between
impactor displacement and air bag pressure. It estimated that the
initial internal pressure would need ``to be increased 2-3 times
depending on the actual kinetic energy of the impactor and the NPRM's
required excursion limits.'' VW stated that ``the above mentioned
pressure increase for the ejection mitigation test will result in a
detuning of the airbag and in deterioration of the side crash test
results'' relevant to NCAP and IIHS consumer information programs. VW
believed there would be a reduction of overall fleet star ratings and a
reduction in occupant safety in conventional side crashes.
The Alliance provided research performed by Toyota that the
Alliance believed ``illustrates the increased OOP risk associated with
the high impact energy (400 Joule impact) and limited excursion (100
mm) requirements proposed in the NPRM.'' In this research, two SUVs and
two passenger cars were tested to the 24 km/h-1.5 second impact test
and subsequently to OOP testing using the Technical Working Group (TWG)
Recommended Practice with an inboard facing 5th percentile adult female
dummy.\148\ When changes were made to the side curtain air bag systems
by increasing internal pressure and coverage to meet a 160 mm
displacement limit when tested at 24 km/h-1.5 seconds, the Alliance
reported that OOP values increased from approximately 80 percent of
IARVs to about 105 percent of IARVs.
---------------------------------------------------------------------------

\148\ The TWG Recommended Procedures were developed to evaluate
the risk of side air bags to children who are out-of-position.
Through a voluntary agreement with NHTSA, vehicle manufacturers
consented to meet the TWG. The agency requests the results of
testing through the Buying a Safer Car program and publishes the
data annually.

---------------------------------------------------------------------------

[[Page 3287]]

Agency Response
It appears from the comments that if the impact speed was 24 km/h,
some manufacturers would have to increase the air pressure in their
side curtain air bags to meet the requirement. We estimate that this
approach to meet a 24 km/h test would add $7.53 to the $31 incremental
cost of meeting a 20 km/h test. This added cost is for a larger
capacity inflator. Some manufacturers have commented that increasing
air bag pressure in current bags to meet a 24 km/h-1.5 second test
increases HIC values measured in a side impact test and IARVs measured
in OOP tests. If manufacturers were attempting to bring a curtain air
bag into compliance that was well outside of the 100 mm limit by only
increasing internal pressure, the air bag would likely become more
rigid. Whether those increased HIC values and IARVs in OOP tests from
increased air bag pressure pose an unreasonable safety risk has not
been shown, but so-called ``negative trade-offs'' concern the agency in
any rulemaking.
New side curtain air bag designs appear to be evolving that show
promise in meeting the 100 mm limit of impactor displacement when
tested to a 24 km/h-1.5 second condition, without undesirably affecting
side impact and OOP test results.
However, if these systems require significantly more air bag
volume, they may be more costly than a system that meets a 24 km/h
requirement by increased air pressure. We estimate that, for a vehicle
with an air bag system that uses higher volume and more material to
meet the 24 km/h requirement, $37.87 would be added to the $31
incremental cost of a system that meets a 20 km/h requirement.\149\
---------------------------------------------------------------------------

\149\ A curtain air bag with more volume will require more air
bag material and may also utilize an extra inflator if a single
inflator is not sufficient. An extra inflator adds significant cost
to a curtain air bag system.
---------------------------------------------------------------------------

Air bag supplier Takata met with the agency on July 28, 2009, to
discuss its effort at designing an ejection mitigation system to meet a
December 2006 NHTSA ejection mitigation research test procedure at a
displacement limit of 100 mm at 24 km/h-1.5 second impact.\150\ Takata
explained that it believed there were two potential ways of meeting the
requirement: By way of retaining a strong membrane over the window
opening, or by absorbing the impactor energy. For the first approach,
Takata stated that the strong membrane could be achieved by laminated
glazing or a high stiffness/pressure curtain. The second energy
absorption method could be achieved by air bags of increased volume or
air bags of a different shape to increase impactor stroke. Takata said
it chose this second approach, to develop an air bag of a different
shape.\151\
---------------------------------------------------------------------------

\150\ Docket NHTSA-2006-26467-0019.
\151\ We note that Takata claimed that it achieved the necessary
performance by a change in shape, rather than an increase in
pressure or volume.
---------------------------------------------------------------------------

Takata stated that a new air bag design it has developed was
integrated into a sedan and tested to the 24 km/h-1.5 second and 16 km/
h-6 second impacts, and to TWG OOP requirements using both the 5th
percentile adult female and 6-year-old (6YO) child dummies. The
greatest displacement for the 24 km/h-1.5 second test was approximately
82 mm at A1. The greatest displacement at the 16 km/h-6 second test was
approximately 79 mm at B1. The air bag pressure at time of impact was
reported as 30 kPa.
The results from the TWG testing are shown in Takata's docket
submission. The 5th percentile adult female results have a maximum
value of approximately 55 percent of the IARVs. For the 6YO child
dummy, no injury measure exceeded 20 percent of the IARVs.
Takata determined that its new shape curtain could meet the 100 mm
displacement limit without advanced glazing with a sufficient
compliance margin in a sedan design. At the time of the presentation,
Takata indicated that it was working on increasing the compliance
margin for a sport utility vehicle (SUV) design and working with a
vehicle manufacturer to introduce the technology to the market.
In its comment to the NPRM, the Alliance stated that NHTSA should
not interpret information about the performance of innovative side air
bag design concepts developed in an attempt to meet the NPRM to mean
that ``the requirements of the NPRM are practicable.'' \152\ The
Alliance claimed that the air bag supplier design evaluations have not
addressed the following areas: The ability of the air bags to be
deployed in time for a side impact and provide adequate side impact
protection; the ability to integrate these bags with FMVSS No. 201
countermeasures; the ability to function in a complete vehicle
environment; and the ability to implement this technology across
vehicle architectures.
---------------------------------------------------------------------------

\152\ NHTSA-2009-0183-0029, p. 20.
---------------------------------------------------------------------------

We understand that integrating a component into a full vehicle
design involves many factors. However, the Alliance did not provide a
convincing discussion as to why NHTSA should not consider a system such
as Takata's an indication of the practicability of meeting a 24 km/h-
1.5 second impact test.
The Alliance and others questioned whether innovative systems could
be packaged in a vehicle to meet FMVSS No. 201 requirements. The
commenters did not explain how new ejection mitigation side air
curtains would pose unique design problems that would impede the
ability to certify to FMVSS No. 201, when current vehicles with
rollover side air curtains already are certified to that standard.
There was no showing that changes to the air curtains or to the
inflator will present insurmountable problems in packaging the
equipment to FMVSS No. 201. It also appears that Takata is now working
on implementing its system across vehicle architectures. Takata has
indicated that its new system has been successfully integrated into a
passenger car \153\ and is in the midst of SUV integration. Takata did
not provide cost data.
---------------------------------------------------------------------------

\153\ The Toyota data provided by the Alliance indicated that it
was more difficult to meet TWG guidelines in the passenger
environment than in SUVs.
---------------------------------------------------------------------------

The proposed 24 km/h-1.5 second impact has been reduced to 20 km/h-
1.5 second in this final rule after our reanalysis of the technical
basis for the energy requirement and our FRIA analysis showing a 20 km/
h requirement to be more cost effective. With this reduction in
impactor speed, vehicles will be able to meet the final rule's
requirements with fewer changes to existing designs. Data from agency
testing of production vehicles presented earlier in this preamble
demonstrate the practicability of the requirements of this final rule.
The MY 2007 Mazda CX9 was able to meet the performance tests in the
final rule (20 km/h), without modification. This vehicle had a 5-star
side impact rating in the 2007 NCAP program.
We recognize that most side curtains will need design changes to
various degrees to meet the requirements of this final rule. As Takata
indicated in its 2009 meeting, there are several ways to possibly
improve performance in the ejection mitigation test. Manufacturers will
have to decide what suits their particular situation best.
Manufacturers could increase air bag internal pressure to make the air
bag stiffer and/or increase the volume to make the air bag thicker.
They could possibly change the air bag shape, such as Takata has done,
reducing the need for drastic changes in pressure and volume. They
might decide to use advanced glazing to

[[Page 3288]]

supplement ejection mitigation side air curtain performance in meeting
the 20 km/h-1.5 second test. In addition, the availability of lead time
and a phase-in schedule and advanced credits will provide manufacturers
time and flexibility to implement design changes to meet the standard.
Lastly, the Alliance referred to data presented to NHTSA by Ford in
a September 10, 2008 meeting \154\ obtained by a load cell Ford placed
on the impactor shaft behind the headform. The Alliance believed that
``[p]reliminary testing has shown the need to further research energy
and excursion targets to ensure a `balanced approach' between excursion
and curtain stiffness (load cell measurement) in order to avoid
unintended consequences.'' In response, to our knowledge, no one has
established the biomechanical relevance of a uniaxial load measurement
on the shaft of an ejection impactor to occupant injury. Until and
unless such a relationship can be established, the agency has no
reasonable way to judge such data.
---------------------------------------------------------------------------

\154\ NHTSA-2006-26467-0016.
---------------------------------------------------------------------------

l. Vehicle Applicability

This standard applies to passenger cars, multipurpose passenger
vehicles (MPVs), trucks and buses with a GVWR of 4,536 kg (10,000 lb)
or less, except as noted in this section. Manufacturers are installing
or plan to install side impact air bag window curtains in many of these
vehicles. These side air bag window curtains are capable of meeting
FMVSS No. 214's pole test requirements, which apply to passenger cars,
MPVs, trucks and buses with GVWR of 4,536 kg or less. An FMVSS No. 214
air bag window curtain system can be augmented for use as an ejection
mitigation window curtain system.
1. Convertibles
The NPRM tentatively determined that the standard should apply to
convertibles. We requested comments on the practicability of certifying
convertibles to the proposed performance test with door-mounted
ejection mitigation curtains and/or advanced glazing.
Comments
All comments from vehicle manufacturers and air bag manufacturers
opposed the inclusion of convertibles in FMVSS No. 226 for
practicability reasons. Many stated that there was no technology that
would allow a convertible to meet the proposed requirements. The AIAM
explained that although convertibles can meet FMVSS No. 214's pole test
using a door-mounted upwardly deploying air bag, the inflated bag does
not have a door frame to which the curtain can be tethered to achieve
the lateral stiffness needed for ejection mitigation. Further, the
curtains need to be retained by the convertible top, which may not have
the same retention capability as the door trim of conventional
vehicles.
The Alliance informed the agency that the agency was incorrect in
thinking that research from Porsche indicated the feasibility of a
door-mounted air bag system for ejection mitigation. The Alliance
explained that Porsche meant to describe a ``technologically neutral
solution'' for a coupe, ``which unlike a convertible, can be fitted
with framed windows.'' The Alliance stated that it believed that
``advanced glazing, with or without a door[hyphen]mounted airbag, does
not constitute a practicable compliance solution for convertibles.''
AORC stated that its members have been working on this technology but
have not yet verified performance relative to this specification.
Comments from Pilkington and from Public Citizen supported
including convertibles in the applicability of the standard.
Agency Response
We have decided that the standard will not apply to convertibles.
We found compelling the practicability concerns raised by vehicle
manufacturers and air bag suppliers related to the near-term technical
challenges involved with producing a compliant convertible.
In NPRM preamble, we mentioned Porsche's development of door-
mounted curtains that would deploy upward toward the vehicle roof in a
rollover. Comments from the Alliance to the NPRM indicated that Porsche
was not developing this curtain for ejection mitigation of
convertibles, but rather for a coupe.
We sought comments on the feasibility of a door-mounted upwardly-
deploying curtain for ejection mitigation of convertibles. Comments
from vehicle manufacturers and air bag suppliers indicated that current
air bag designs are not effective for ejection mitigation purposes in
vehicles without a window frame because the air bag cannot be tethered
at the leading edge of the curtain without a firm door frame to which
to attach. We concur that an ejection mitigation side curtain air bag
must be sturdily tethered in order to meet the displacement limits of
this final rule. At this time, convertibles lack the rigid door frame
or door pillar to which the ejection mitigation side curtain air bag
could be tethered. We agree that current ejection mitigation side
curtain air bag designs cannot be used on convertibles, and we are not
aware of information indicating the feasibility of developing designs
that could be used on convertibles in the foreseeable future.
Advanced glazing will not be an available countermeasure for use in
convertibles to meet the standard. Honda and others stated that the
advanced glazing on a convertible door is likely to fall out in a
rollover crash due to the lack of roof structure and rigid structure
around the window opening. In our review of field data on advanced
glazing, we found sufficient evidence of glazing vacating the window
opening in real world rollover crashes that we decided not to allow
movable advanced glazing to be the sole countermeasure used to meet the
displacement limits of the standard. Also, movable glazing cannot be
present during the 16 km/h-6 second test. With these changes, the
glazing-only countermeasure is no longer viable for a movable window
opening. A convertible would have to pass the 16 km/h-6 second test
with just the door mounted ejection mitigation side curtain air bag. As
previously discussed, we do not believe it is practicable for
convertibles to meet the test with only an air bag at this time.
In response to a comment from the Alliance, our reasons for
excluding convertibles from the standard are not based on FMVSS No.
216's exclusion of convertibles from roof crush resistance
requirements. However, we acknowledge that convertibles can pose unique
challenges related to the roof. As shown previously in this preamble,
there were 16 fatalities and 18 MAIS 3+ injuries due to ejections
through a convertible roof closed prior to the crash. For convertibles
where the roof was open, the fatalities and MAIS 3+ injuries were 31
and 84, respectively. This indicates that about half of the ejection
fatalities through the roof area occurred even when the roof was closed
before the crash. (These estimates are based on an extremely small
sample size.) These data reflect the problematic nature of convertible
ejection protection.
2. Original Roof Modified
NHTSA proposed to exclude vehicles whose original roof was
replaced, raised or otherwise modified. A definition of ``modified
roof'' was adopted. No commenter opposed the proposal. NTEA commented
in support of it. This final rule adopts the proposed exclusion and
definition.

[[Page 3289]]

3. Multi-Stage Manufacture of Work Trucks
NTEA asked that NHTSA exclude work trucks built in two or more
stages (``multi-stage vehicles'') from FMVSS No. 226. NTEA stated that
it expects that if ejection mitigation side curtain air bags are
installed by a chassis manufacturer to meet FMVSS No. 226, ``this
manner of compliance by the chassis manufacturers will result in
restrictive or non-existent pass-through compliance guidance for multi-
stage manufacturers of work trucks.'' The commenter believed that the
purchasers of these vehicles require an extensive variety of end
designs, ``including bulkheads and partitions to protect the driver
from loose cargo in the back of the vehicle,'' and that the design of
most vehicles will almost certainly affect the performance of the
chassis manufacturers' side curtain air bag systems. The commenter
believed that ``pass-through compliance will prohibit any completions
or alterations that could affect the vehicle's center of gravity thus
potentially affecting the sensor(s) that control side curtain bag
deployment. Also expected to be prohibited for pass-through compliance
would be any changes to the trim or headliner around any of the
regulated window space.'' \155\
---------------------------------------------------------------------------

\155\ NHTSA-2009-0183-0017, p. 3.
---------------------------------------------------------------------------

NHTSA is declining the request for a blanket exclusion of all work
trucks built in two or more stages from FMVSS No. 226. To provide
relief to multi-stage manufacturers and alterers, we have already
excluded vehicles whose original roof was removed, in part or in total,
by an alterer or final stage manufacturer. That exclusion addresses
designs that will specifically affect side curtain air bag coverage or
inflators for which pass-through guidance might not be available.
A final-stage manufacturer can either stay within the incomplete
vehicle document (IVD) furnished by the incomplete vehicle manufacturer
(which are typically large vehicle manufacturers, such as GM or Ford),
or the final-stage manufacturer can work with incomplete vehicle
manufacturers to enable the final-stage manufacturer to certify to the
new standard.\156\ The final-stage manufacturer can also certify to the
standard using due care based on an assessment of the information
available to the manufacturer.
---------------------------------------------------------------------------

\156\ For a discussion of NHTSA's certification regulations for
final stage manufacturers, see 71 FR 28168, May 15, 2006, Docket No.
NHTSA-2006-24664, Response to petitions for reconsideration of a
final rule implementing regulations pertaining to multi-stage
vehicles and to altered vehicles. The Background section of that
document provides concepts and terminology relating to the
certification of multi-stage vehicles.
---------------------------------------------------------------------------

NTEA contended that work-performing vehicles should be excluded
from the standard because producing these vehicles may involve changing
the vehicle's center of gravity, which the commenter stated could
potentially affect the sensor(s) that control side curtain air bag
deployment. The standard adopted today does not specify any
requirements for the rollover sensor. In the compliance test, we
manually deploy the ejection mitigation side curtain air bags with the
stationary vehicle set up in the test laboratory. Changing the center
of gravity of the vehicle would not affect our ability to manually
deploy the side curtain air bags in the laboratory test. Likewise,
lowering the vehicle floor would not affect the ability to manually
deploy the side curtain air bags in the test.
Since no certification requirement exists with regard to the
sensor, the IVD will not have center of gravity restrictions regarding
sensor performance. We have no sound reason to exclude multi-stage work
vehicles from the standard based on possible restrictions relating to
sensor performance.
Furthermore, we do not believe that changing the center of gravity
of the vehicle will affect whether or not an ejection mitigation side
curtain air bags deploys in a real world rollover. We believe that
incomplete vehicle manufacturers will be able to develop rollover
detection technology that can address variability in the vehicle's
center of gravity.\157\ Sensors that are based on roll angle and roll
rate can be made to deploy the air bag when the vehicle rolls, despite
changes to the center of gravity of the vehicle involved in installing
bulkheads, partitions, etc., to which NTEA alludes. However, such
changes may have an effect on the optimization of the sensor for the
particular vehicle, which could result in the systems deploying earlier
or later than would otherwise be the case. Nonetheless, even without
sensor optimization, work vehicles with ejection mitigation side
curtain air bags would continue to provide ejection protection to their
occupants. If these vehicles were excluded because of center of gravity
changes, they would offer no ejection protection in rollovers and no
protection against ejection in side impacts.
---------------------------------------------------------------------------

\157\ Mercedes' comment to the NPRM indicated that vehicle
manufacturers will work toward developing rollover detection
technology for use in large vehicles with center of gravity
different than those of passenger cars.
---------------------------------------------------------------------------

Some modifications made by a final-stage manufacturer or alterer to
the interior of the vehicle could affect the vehicle's compliance with
FMVSS No. 226. An example of this is installing a partition. NTEA
sought to exclude multi-stage manufactured vehicles with bulkheads and
partitions from FMVSS No. 226 since installation of a bulkhead or
partition ``will almost certainly affect the performance of the chassis
manufacturers' side curtain air bag systems.''
We decline to adopt a blanket exclusion of multi-stage vehicles
with bulkheads or partitions in work vehicles.\158\ Such an exclusion
would be unreasonably broad. Bulkheads and partitions can be installed
so as not to interfere with the deployment of ejection mitigation side
curtain air bags. Bulkheads and partitions can be designed to allow for
sufficient clearance to allow the air bags to deploy, or may have
break-away features to allow a curtain air bag to deploy.\159\ The
incomplete vehicle manufacturers will be able to provide the
appropriate guidance to allow for pass-through certifications. Even if
the IVD does not provide guidance, the final-stage manufacturer will be
able to ascertain the clearance needed to install the bulkhead or
partition. The bulkhead and partition designs will enable the final
customer to purchase a vehicle certified to FMVSS No. 226 and to
provide the protection of side curtain air bags to their employees who
will be occupying the vehicle.
---------------------------------------------------------------------------

\158\ As discussed later in this section, we are allowing a
limited exclusion of ``security partitions'' in multi-stage
manufactured or altered law enforcement vehicles, correctional
institution vehicles, taxis and limousines.
\159\ See 75 FR 12123, 12128-12131, March 15, 2010, for a
discussion of approaches that are available to multi-stage
manufacturers enabling them to certify to FMVSS No. 214's pole test
using side impact curtain air bags in vehicles with partitions.
---------------------------------------------------------------------------

We disagree with the Alliance's comment that the National Traffic
and Motor Vehicle Safety Act precludes the agency from applying FMVSS
No. 226 to vehicles with partitions. Partitioned vehicles are not a
vehicle type. In any event, it is not impracticable to meet the
standard with a partition. Manufacturers will be able to determine how
to provide a clearance for the ejection mitigation side curtain air
bags and/or design and position the partition to take advantage of the
shape of the air bag.
NTEA also expressed concerns related to testing cost for those
multi-staged vehicles for which pass-through would not be available. It
stated that it received estimates for testing costs ``from $9,000 to
$25,000 for 1-3 rows at 5 tests per

[[Page 3290]]

window, and $14,000 to $40,000 for 1-3 rows at 8 tests per window
(assuming new airbags and glass for each impact.'' We do not believe
those estimates are accurate. In the PRIA, the agency estimated testing
costs would consist of $100 for labor, $300 for an air bag and $400 for
advanced glazing.\160\ For a 3 row vehicle, assuming testing every
target at both test speeds; this would result in a testing cost
estimate of $19,200.
---------------------------------------------------------------------------

\160\ PRIA, pg. V-21.
---------------------------------------------------------------------------

NTEA also questioned the potential availability of testing
facilities to fulfill the need of the multi-stage manufacturers. We
believe testing facilities will be able and willing to provide the
market demand for testing. The agency purchased a state-of-the-art
ejection mitigation test device for about $150,000 and received
delivery in 4\1/2\ months.
In addition, multi-stage manufacturers have an additional year
after the phase-in is completed to certify compliance to FMVSS No. 226.
This leadtime available to multi-stage manufacturers will provide
enough time for the manufacturers to work with incomplete vehicle
manufacturers to address pass-through certification guidance or perform
whatever testing they deem is necessary for certification purposes,
including the basis for certifying vehicles with a partition or
bulkhead.
NTEA noted that it expected any change to the trim or headliner
around any of the window space to be prohibited by the IVD for pass-
through compliance. We do not agree. In its comment, Nissan stated that
it did not anticipate the headliner would affect performance of the
side curtain air bag system. NTEA did not provide information showing
otherwise. Further, the multi-stage manufacturers have ample lead time
to work with incomplete vehicle manufacturers to develop acceptable
trim and headliner changes or to work with test laboratories themselves
to assess what changes to the trim or headliner can be made that will
not affect the performance of the ejection mitigation system.
We are adopting a suggestion of NTEA with regard to partitions. One
of NTEA's comments related to vehicles with partitions or bulkheads
that separate areas of the vehicle with and without seating positions.
It stated that to the extent the proposed standard applied to multi-
stage produced trucks, ``NHTSA [should] consider adopting testing
parameters similar to those found in FMVSS 201 to effectively exclude
any targets that are located behind the forward surface of a partition
or bulkhead * * *. We believe it is neither practical nor beneficial to
require test target points that could not possibly be contacted by the
head of an occupant seated forward of the partition.'' \161\
---------------------------------------------------------------------------

\161\ This provision is found in S6.3(b) of FMVSS No. 201.
Footnote added.
---------------------------------------------------------------------------

We find merit in this suggestion to be consistent with FMVSS No.
201. If there is a permanent partition or bulkhead that separates areas
of the vehicle with designated seating positions (DSgPs) from areas
that do not have DSgPs, we believe there is no sensible reason to
target daylight openings in the latter area. The likelihood of an
occupant being ejected from an opening in an area without a DSgP is
low. However, to reduce the likelihood an occupant would be in the area
without a DSgP, the partition or bulkhead must be fixed to the vehicle
and not provide access for an occupant to pass through it. A partition
with a door would not be considered as separating the occupant space
from non-occupant space.
This final rule makes a limited exclusion of security partitions in
multi-stage manufactured or altered law enforcement vehicles,
correctional institution vehicles, taxis and limousines. The Alliance
and Volvo commented that police vehicles, taxis and limousines with
partitions between the first and second rows should be excluded from
FMVSS No. 226. The Alliance claimed that any partition installed in a
way to not interfere with curtain deployment would leave ``a
significant gap between the outboard edge of the partition and the
inboard surface of the vehicle trim thus rendering it unable to provide
either complete security or privacy.'' The Alliance believed that
upwardly-deploying air bags are not feasible. Volvo believed that
installing a partition is ``always done by a third party and is, for
this reason, beyond the vehicle manufacture[r]'s control. To take this
potential adaptation into consideration during design, development, and
testing would not be possible.''
Considering that law enforcement vehicles are more likely to be
involved in risky driving operations than other passenger vehicles,
NHTSA prefers that the vehicles provide ejection mitigation
countermeasures. However, we agree to exclude some vehicles from the
standard under certain circumstances due to practical considerations.
Security partitions (e.g., prisoner partitions) are necessary for
the safety and security of law enforcement officers. These partitions
must be flush against the sides of the vehicle to prevent a rear seat
occupant's hand or article from intruding into the officer's
compartment. A partition installed by a final-stage manufacturer in an
incomplete vehicle or by an alterer in a completed vehicle will
interfere with the ejection mitigation side curtain air bags currently
being produced. The curtains are tethered from the A-pillar to the C-
pillar, so a partition between the 1st and 2nd rows or between the 2nd
and 3rd rows will prevent the curtain from properly covering the window
opening.
After considering the comments, we believe it would be difficult
for incomplete vehicle manufacturers providing vehicles to the final
stage manufacturers or alterers to have an alternative design which
would be compatible with a security partition.\162\ Thus, we are
excluding from the standard law enforcement vehicles, correctional
institution vehicles, taxis and limousines, if they have a fixed
security partition separating the 1st and 2nd or 2nd and 3rd rows, and
if they are manufactured in more than one stage or are altered. We do
not believe that compatible designs, such as a split curtain, are
impossible. Rather, we believe compatible designs will need time to
develop.
---------------------------------------------------------------------------

\162\ In FMVSS No. 214, we do not exclude police and other
vehicles from meeting the standard's pole test requirements. The
pole test does not apply to rear seats. To meet the pole test,
vehicles must provide head, thorax and pelvic protection. Side
window curtains can be used to meet the pole test, but seat- and
door-mounted air bags in the front seat are also available for use
as well in meeting FMVSS No. 214. Thus, multi-stage manufacturers
can work together such that the vehicle in which the partition is
installed can meet FMVSS No. 214 with a front seat seat-mounted or
door-mounted air bag. At this time there is no countermeasure
available from incomplete vehicle manufacturers that could meet
FMVSS No. 226 with a security partition flush to the side of the
vehicle. A countermeasure only using advanced glazing for movable
windows will not meet today's requirements because the 16 km/h test
must be passed without glazing in place.
---------------------------------------------------------------------------

We do not believe there is any technical barrier to designing
curtain(s) to cover side windows that are separated by a partition with
two separate curtains. The front of the first row curtain and rear of
the second row curtain could be tethered to the A- and C-pillars,
respectively. Each curtain could be separately tethered to the B-
pillar. We also believe that such a split curtain system could use a
single inflator to feed both air bags. The trim on the B-pillar and on
the header in front and behind the partition could be split to allow
the two air bags to deploy independently. Development of such a vehicle
specific curtain would likely require time, and the resources available
to an incomplete vehicle manufacturer, i.e., a large vehicle
manufacturer.

[[Page 3291]]

Because we believe incomplete vehicle manufacturers are able to develop
a curtain design that is compatible with a partition, we are not
extending this exclusion to law enforcement vehicles, correctional
institution vehicles, taxis and limousines if they are built in a
single stage. We believe it is practicable for such a vehicle to have a
single design to meet the final rule and that manufacturers of such
vehicles will be capable of applying the necessary resources to meet
the standard.
4. Other Issues
i. Vehicles That Have No Doors and Walk-In Vans
Comments were requested but none were received on whether vehicles
are still being manufactured that have no doors, or exclusively have
doors that are designed to be easily attached or removed so that the
vehicle can be operated without doors. NHTSA proposed excluding the
vehicles on practicability grounds. This final rule adopts the
exclusion.
We did not receive comments on the proposed exclusion of walk-in
vans. This final rule excludes the vehicles on practicability grounds.
ii. Vehicles Over 4,536 kg
A few commenters requested that the standard not be limited to
vehicles under 4,536 kg (10,000 lb) GVWR. Batzer and Ziejewski stated
that school buses over 4,536 kg offered ejection mitigation by virtue
of the divider-bar requirement and, therefore, commercial vehicles over
4,536 kg GVWR should be covered as well. The commenter stated that
``[w]hile this could conceivably cause some manufacturers distress,
they could be provided the opportunity to petition NHTSA for a waiver,
and notify the purchaser that their vehicle does not fully comply with
pertinent FMVSS regulations.'' \163\
---------------------------------------------------------------------------

\163\ NHTSA-2009-0183-0009, p. 1.
---------------------------------------------------------------------------

We did not propose to apply the standard to vehicles with a GVWR
over 4,536 kg and did not discuss the possibility of this application
of the standard or request comments on this issue. Thus, the requests
are outside the scope of the rulemaking. Also, we note that the
National Traffic and Motor Vehicle Safety Act provides very limited
authority to NHTSA to grant exemptions to manufacturers from meeting
the requirements of the Federal motor vehicle safety standards. General
authority to grant waivers is not available.

m. Lead Time and Phase-In Schedules; Reporting Requirements

Motor vehicle manufacturers will need lead time to develop and
install ejection mitigation countermeasures and rollover sensors.
Although inflatable side curtain air bags are being developed in new
vehicles to meet the September 1, 2010 date that begins the phase-in of
the FMVSS No. 214 final rule for the pole test, to meet the
requirements adopted today, these side curtains will have to be made
larger to cover more of the window opening, will have to be made more
robust to remain inflated longer, and will have to be enhanced (by
tethering and other means) to retain vehicle occupants within the
vehicle. Moreover, rollover sensors will need to be installed to deploy
the ejection mitigation countermeasures in rollover crashes, to augment
the sensors needed to deploy the side curtains in side impacts.
Our tests of vehicles to the NPRM's proposed requirements found
that vehicle manufacturers were at different stages with respect to
designing inflatable ejection mitigation side curtains that meet the
requirements then-proposed. Vehicle manufacturers also face unique
manufacturing constraints and challenges, e.g., each face differences
in the technological advances incorporated in their current air bag
systems, differences in engineering resources, and differences in the
numbers and type of vehicles for which ejection mitigation systems will
need to be incorporated. NHTSA believed that these differing situations
can best be accommodated by phasing in the ejection mitigation
requirements and by allowing the use of advanced credits.
NHTSA proposed that the phase-in would be implemented in accordance
with the following schedule: 20 percent of each manufacturer's vehicles
manufactured during the first production year beginning three years
after publication of a final rule (for illustration purposes, assuming
the final rule is issued in January 2011, under the NPRM that effective
date would have been September 1, 2014); 40 percent of each
manufacturer's vehicles manufactured during the production year
beginning four years after publication of a final rule; 75 percent of
vehicles manufactured during the production year beginning five years
after publication of a final rule; and all vehicles (without use of
advanced credits) manufactured on or after the September 1st following
six years after publication of a final rule.
NHTSA also proposed to permit ``limited line'' manufacturers that
produce three or fewer carlines the option of achieving full compliance
when the phase-in is completed. The NPRM also proposed that
manufacturers of vehicles manufactured in two or more stages and
alterers would not be required to meet the phase-in schedule and would
not have to achieve full compliance until one year after the phase-in
is completed. NHTSA proposed reporting requirements to accompany the
phase-in.
Comments
The Alliance asked for an additional year of lead time, believing
that it will take at least 12 months after publication of the final
rule to obtain impactors meeting the specified performance
requirements. Further, the Alliance stated that ``even after the
devices have been acquired, they must be installed, pre[hyphen]tested
and run[hyphen]in before they can produce consistent test results which
are necessary prior to the initiation of a development process that
will yield reproducible results. These logistical steps will
unfortunately eliminate one[hyphen]third of the lead[hyphen]time
intended by the NPRM and because manufacturers will utilize the
impactor in the development process, this lost time will significantly
impact manufacturers' ability to achieve compliance in the first year
of the phase[hyphen]in as proposed.''
The AIAM stated that an additional year of lead time is needed for
vehicles not utilizing roof rail mounted curtain air bags to meet FMVSS
No. 214. It claimed that these vehicles would need significantly
greater redesign and that this work cannot begin until the final rule
is issued.
Several vehicle manufacturers asked for the application of advanced
credits in the 100 percent certification year. The Alliance contended
that manufacturers producing vehicles that do not meet FMVSS No. 214 by
way of a side window air bag curtain will need to use credits in the
100 percent year to be able to redesign vehicles to meet FMVSS No. 226.
The commenter stated its belief that vehicles with a GVWR over 2,722 kg
(6,000 lb) will need more lead time to install larger air bag cushions
and inflators to cover the vehicles' larger windows. Porsche stated
that compliance with future ejection mitigation requirements will
necessitate significant changes to the body-in-white, greenhouse and
interior fittings which can only be implemented with the launch of a
new vehicle model. Mercedes commented that large vehicles, such as the
Mercedes-Benz Sprinter, have large window openings

[[Page 3292]]

which Mercedes stated will require a completely new generation of large
air bag curtains.
In contrast, glazing manufacturers and consumer groups requested a
one-year reduction in both the lead time and phase-in of the final
rule. Advocates requested that the phase-in be changed to 40 percent,
75 percent and 100 percent. Guardian stated that ``advanced glazing
technology is available today.'' EPGAA stated ``many manufacturers'
models already incorporate advanced glazing and airbags, and as NHTSA's
testing shows, little or no changes are required to existing airbags to
achieve compliance with the proposed standard.''
Agency Response
To accelerate the ejection mitigation benefits provided by this
final rule, the agency has decided to reduce the lead time by a year,
to two years of lead time, and to require larger percentages of a
manufacturer's fleet to meet the new standard in the first two years of
the phase-in schedule than proposed. The overall timetable is
comparable to the schedules in FMVSS Nos. 214 and 216, and with the
Phase I advanced air bag implementation in FMVSS No. 208.
We reject the argument of the Alliance that a lack of availability
of impact testers will delay compliance. Many vehicle manufacturers and
air bag manufacturers presented test data to the agency indicating they
have access to impact testers and are able to perform the tests. The
lead time and phase-in timetable provided will afford sufficient time
to perform compliance tests.
We reject the AIAM request for increased lead time for vehicles
that do not or will not use curtains to meet the FMVSS No. 214 upgrade.
If manufacturers need more time for such vehicles, they can address
this through the flexibility offered by the phase-in and credits. AIAM
indicated that the additional year was needed to ``fully separate the
214 and ejection mitigation phase-in periods.'' We do not know of a
reason why full separation is needed between completion of the phase-in
of the FMVSS No. 214 upgraded requirements and the first year of the
FMVSS No. 226 phase-in.
The 24 km/h-1.5 second impact proposed in the NPRM has been reduced
in this final rule to 20 km/h-1.5 seconds after our reanalysis of the
technical basis for the energy requirement. With this reduction in
impactor speed, it is expected that fewer changes will be needed to
existing designs to meet the final rule's requirements. Data from
agency testing of production vehicles presented earlier in this
preamble showed that the MY 2007 Mazda CX9 was able to meet the
performance tests in the final rule, without modification. Given this
reduction in stringency of the test, fewer and/or less substantial
vehicle design changes will be needed to meet the standard, and less
lead time required to begin phasing in the requirements across the
fleet. Accordingly, we believe that two years of lead time are
sufficient prior to the phase-in. For the same reason, a greater
percentage of vehicles will be able to meet the requirements in each of
the phase-in years. Thus, we are slightly increasing the percentages of
vehicles in the fleet that will need to meet the ejection mitigation
standard during the first two years of the phase-in.
However, vehicle manufacturers are at different stages with respect
to designing ejection mitigation systems, and also face differences in
the challenges they face and the resources available to them. To
provide flexibility to manufacturers in managing their resources to
meet this schedule, this final rule provides a multi-year phase-in
period and allows credits to be used in the 100 percent phase-in year.
The agency did allow the use of credits for the 100 percent year for
the advanced air bag rulemaking in FMVSS No. 208. We generally agree
with the comments from AIAM stating that credits allow for manufacturer
flexibility and earlier safety benefits. The added flexibility of
allowing credits in the 100 percent year will allow manufacturers a
more seamless introduction of compliant vehicles while enhancing their
ability to manage their engineering and manufacturing resources.
We found particularly compelling the comments from Mercedes
(regarding the Sprinter), Porsche (regarding the long product cycle of
their sports cars), Volvo and other manufacturers. The use of advanced
credits in the 100 percent year will provide relief to manufacturers of
vehicles with very large windows, vehicles with very long product
cycles, and vehicles that are not as far along having side curtain air
bags as other vehicles.
The comments showed that manufacturers have unique problems
depending on factors such as organizational resources, product mix, and
product life cycle. A manufacturer with many different models may have
more flexibility in determining which vehicles to certify and in
accruing credits. However, this larger portfolio may require greater
effort to bring all vehicles into compliance. On the other hand,
manufacturers with small portfolios may have less flexibility, but may
be able to focus resources on a much smaller number of vehicles to
upgrade. The final rule phase-in schedule, even with the added year of
credit use, may result in some manufacturers needing to reassess and
modify their plans. Nonetheless, we believe that the two-year lead time
and the four-year phase-in correctly balances the manufacturers' needs
for flexibility and the needs of the agency to limit the length of time
for the phase-in to a reasonable period and achieve the safety benefits
of the final rule as quickly as practicable.
NHTSA has decided that the lead time and phase-in will continue to
apply to all vehicles under 4,536 kg (10,000 lb).\164\ We have balanced
the safety need to implement the requirements of this final rule as
quickly as practicable with the realistic burdens of manufacture.\165\
We believe that the relief provided by the additional year to use
credits will allow manufacturers the flexibility to address any
specific problems associated with bringing heavier vehicles into
compliance. Some vehicle manufacturers pointed to FMVSS Nos. 214 and
216 as examples of standards where the certification schedule gave
special treatment to heavier vehicles. For example, for FMVSS No. 214,
the agency stated that more time was being provided for the pole test
of vehicles with GVWR greater than 3,856 kg (8,500 lb) because the
vehicles had never been regulated in FMVSS No. 214 and thus ``more
redesign of the vehicle side structure, interior trim, and/or
optimization of dynamically deploying head/side protection systems may
be needed in these vehicles than in light vehicles.'' \166\ We do not
find the analogy persuasive. The changes needed to meet FMVSS Nos. 214
and 216 were primarily

[[Page 3293]]

structural. FMVSS No. 226 countermeasures for larger vehicles, as
indicated by commenters, will likely be larger curtains and longer-
lasting inflators. The two-year lead time and phase-in timetable for
FMVSS No. 226, and the use of credits in the 100 percent year, will
provide the time needed to meet the standard.
---------------------------------------------------------------------------

\164\ This does not include limited line manufacturers,
manufacturers of multi-stage vehicles, and alterers. Those
manufacturers are not required to achieve full compliance until one
year after the phase-in is completed.
\165\ The agency estimates that vehicles between the ranges of
2,722 kg (6,000 lb) to 4,536 kg (10,000 lb) and 3,856 kg (8,500 lb)
to 4,536 kg (10,000 lb) constitute 25 percent and 6 percent of the
annual production of vehicles with a GVWR less than 4,536 kg (10,000
lb). The 25 percent estimate can be found in the FRIA for the recent
FMVSS No. 216 upgrade (Docket NHTSA-2009-0093). The 6 percent
estimate is derived from MY 2010 submissions to the NCAP Buying a
Safer Car program and Ward's 2009 Yearbook. We believe that to
exclude 25 percent of vehicles less than 4,536 kg (10,000 lb) from
meeting FMVSS No. 226 until the end of the phase-in, as would be the
case for the 2,722 kg (6,000 lb) split, would be unacceptable in
terms of the delayed safety benefits. We also believe that the 6
percent of vehicles, represented by the 3,856 kg (8,500 lb) split,
represents a number that can be accommodated with accrued advanced
credits.
\166\ 72 FR 51911.
---------------------------------------------------------------------------

We do not agree with the commenters expressing concern that
countermeasures for heavier vehicles may have more OOP issues and
therefore, in general, need more time to comply. Toyota data submitted
by the Alliance indicated that OOP concerns were actually greater for
passenger cars than they were for larger vehicles. Further, there is
the potential of using advanced glazing in these heavier vehicles,
particularly for fixed windows.
We take this opportunity to correct Public Citizen's apparent
misinterpretation of the PRIA that led the commenter to believe that
the agency estimated that 25 percent of MY 2011 vehicles would be able
to comply with the NPRM. In the PRIA, we said that none of the curtain
systems tested met the proposed 100 mm displacement limit. However,
although none of the current curtain air bags met the displacement
requirement, the non-compliant curtains would provide some amount of
ejection mitigation. Since we do not want to double count the potential
benefits of the rulemaking with the benefits that the non-compliant
curtains already provide, these potential benefits were excluded from
the benefits estimate.\167\ Thus, the 25 percent value quoted by Public
Citizen is an adjustment factor, not a compliance rate.\168\
---------------------------------------------------------------------------

\167\ For example, a curtain air bag that completely covers the
front window opening and meets the 100 mm displacement requirement
at A2, A3, and A4, but not A1. We assumed that the air bag system
would provide some benefits, even if it failed to meet the
displacement requirement at A1.
\168\ The PRIA stated that current ejection mitigation curtain
systems are only 46 percent effective in preventing occupants from
ejection and that 55 percent of MY 2011 vehicles would be equipped
with these non-compliant air bags.
---------------------------------------------------------------------------

Reporting Requirements
The Alliance mentioned that the NPRM requires manufacturers to
report advanced credits 60 days after the end of the production year.
It stated that this means the first report would be due on August 31,
2011. (Under the NPRM the first report would actually have to be filed
60 days after the date of August 31, 2011, rather than on August 31.)
It opined that ``[b]ecause the rule will likely not be finalized until
2011 and the impactors complying with the specifications contained in
the final rule may not be available to all manufacturers until the 2012
timeframe, the Alliance recommended that section 585.105 of the
regulation be revised so as to provide manufacturers up to one year
after the end of the first advanced credit production period to file
their advanced credit phase[hyphen]in report for that year.
We disagree with this request. The commenter's rationale for
putting off the filing of the report for a year was the same one it
used to argue for an increase in lead time by one year, i.e., an
alleged lack of availability of impact testers meeting the final rule
requirements. We disagree with this reason because, as previously
stated, many vehicle manufacturers and air bag manufacturers presented
test data to the agency indicating they have access to impact testers
and are able to perform tests. Further, allowing manufacturers one year
after the end of the MY 2011 production period ends to report would
lead to logistical difficulties for the agency's compliance testing
program. At the time we would be purchasing vehicles for the MY 2011
compliance testing, we would not know which vehicles to purchase for
testing to FMVSS No. 226 without the reports. If the reports were not
due until October 1, 2012, it might be difficult to procure the
certified MY 2011 vehicles at that time.
AIAM and VSC asked that small volume and limited line manufacturers
be exempt from the phase-in reporting until the first year that they
must comply or can earn credits. We agree with the comment. These
entities are exempt from the phase-in requirements, so they should be
exempt from reporting requirements as well.

XI. Costs and Benefits

The FRIA we have placed in the docket analyzes the impacts of this
final rule. A summary of the FRIA follows.
The agency believes that side curtain air bags will be used to pass
the ejection mitigation test. We believe that most manufacturers will
widen the side curtain air bags that they are providing to meet FMVSS
No. 214's pole test requirements, or replace combination (combo) seat-
mounted side air bags with a curtain to pass the impactor test of the
standard adopted today. We assume that for the most part vehicle
manufacturers will install a single-window curtain for each side of the
vehicle, and that these window curtains will provide protection for
occupants of the first three rows.
This final rule will save 373 lives and prevent 476 serious
injuries per year (see Table 42 below). The cost of this final rule is
approximately $31 per vehicle (see Table 43). The cost per equivalent
life saved is estimated to be $1.4 million (3 percent discount rate)--
$1.7 million (7 percent discount rate) (see Table 44 below). Annualized
costs and benefits are provided in Table 45.

Table 42--Estimated Benefits
------------------------------------------------------------------------

------------------------------------------------------------------------
Fatalities...................................................... 373
Serious Injuries................................................ 476
------------------------------------------------------------------------

Table 43--Estimated Costs *
[2009 Economics]
------------------------------------------------------------------------

------------------------------------------------------------------------
Per Vehicle.............................. $31.
Total Fleet (16.5 million vehicles)...... $507 million.
------------------------------------------------------------------------
* The system costs are based on vehicles that are equipped with an FMVSS
No. 214 curtain system. According to vehicle manufacturers'
projections made in 2006, 98.7 percent of Model Year (MY) 2011
vehicles will be equipped with curtain bags and 55 percent of vehicles
with curtain bags will be equipped with a rollover sensor.

Table 44--Cost per Equivalent Life Saved
------------------------------------------------------------------------
3% Discount rate 7% Discount rate
------------------------------------------------------------------------
$1.4M............................................... $1.7M
------------------------------------------------------------------------

Table 45--Annualized Costs and Benefits
[In millions of $2009 dollars]
----------------------------------------------------------------------------------------------------------------
Annualized
Annual costs benefits Net benefits
----------------------------------------------------------------------------------------------------------------
3% Discount Rate....................................... $507M $2,279M $1,773
7% Discount Rate....................................... 507M 1,814M 1,307
----------------------------------------------------------------------------------------------------------------

[[Page 3294]]

The agency received several comments about the PRIA's cost benefit
analysis. Several glazing manufacturers commented that the agency's
analysis underestimated air bag costs, did not adequately consider
benefits of advanced glazing associated with enhanced security, UV
shading, weight reduction, improved energy efficiency, etc., and
overstated the cost of advanced glazing. Public Citizen stated that the
agency underestimated the benefits of FMVSS No. 226 because we
overestimated the effectiveness of ESC. Conversely, IIHS stated we
overestimated the benefits of FMVSS No. 226 because we underestimated
the benefits of FMVSS No. 216.
In the FRIA, NHTSA responds to all relevant comments on the costs
and benefits estimated by the NPRM and PRIA.

XII. Rulemaking Analyses and Notices

Executive Order 12866 (Regulatory Planning and Review) and DOT
Regulatory Policies and Procedures

The agency has considered the impact of this rulemaking action
under Executive Order 12866 and the Department of Transportation's
regulatory policies and procedures. This rulemaking is economically
significant and was reviewed by the Office of Management and Budget
under E.O. 12866, ``Regulatory Planning and Review.'' The rulemaking
action has also been determined to be significant under the
Department's regulatory policies and procedures. NHTSA has placed in
the docket a Final Regulatory Impact Analysis describing the costs and
benefits of this rulemaking action.

Regulatory Flexibility Act

The Regulatory Flexibility Act of 1980, as amended, requires
agencies to evaluate the potential effects of their proposed and final
rules on small businesses, small organizations and small governmental
jurisdictions. I hereby certify that this final rule will not have a
significant economic impact on a substantial number of small entities.
Small organizations and small governmental units will not be
significantly affected since the potential cost impacts associated with
this final rule will not significantly affect the price of new motor
vehicles.
The final rule could indirectly affect air bag manufacturers and
suppliers. These entities do not qualify as small entities.
The final rule will directly affect motor vehicle manufacturers.
The FRIA discusses the economic impact of the final rule on small
vehicle manufacturers, of which there are six. We believe that the
final rule will not have a significant economic impact on these
manufacturers. The standard will employ static testing of the ejection
mitigation system. The test does not involve destructive crash testing.
It only involves the replacement of certain components and small
vehicle manufacturers can perform such testing themselves. They can
certify compliance using a combination of their own engineering
analyses and testing and component testing by air bag suppliers.
Already much of the air bag development work for these small vehicle
manufacturers is done by air bag suppliers. While typically, air bag
suppliers will supply larger vehicle manufacturers during the lead time
and phase-in period of this final rule, this rulemaking accounts for
this limitation by allowing more time to small manufacturers and
limited line manufacturers to comply with the upgraded requirements.
They have a year past the end of the phase-in period to comply. This
additional time provides flexibility to those entities and enough time
to work with the air bag suppliers to meet their needs.
Final-stage vehicle manufacturers buy incomplete vehicles and
complete the vehicle. Alterers modify new vehicles, such as by raising
the roofs of vehicles. In both cases, NHTSA concludes that the impacts
of this final rule on such entities is not significant. Final-stage
manufacturers and alterers engaged in raising the roofs of vehicles
would not be affected by this final rule because the rule excludes
vehicles with raised roofs from the ejection mitigation requirements.
NHTSA believes that work vehicles can be produced in compliance
with the standard. Partitions separating a driver from cargo can be
installed to accommodate an ejection mitigation side curtain air bag by
providing clearance for the air bag. This final rule accommodates
partitions installed in police vehicles, limousines and taxis by final-
stage manufacturer and alterers by excluding those vehicles from the
standard.

Executive Order 13132 (Federalism)

NHTSA has examined today's final rule pursuant to Executive Order
13132 (64 FR 43255, August 10, 1999) and concluded that no additional
consultation with States, local governments or their representatives is
mandated beyond the rulemaking process. The agency has concluded that
the rulemaking would not have sufficient federalism implications to
warrant consultation with State and local officials or the preparation
of a federalism summary impact statement. The final rule would not have
``substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.''
NHTSA rules can preempt in two ways. First, the National Traffic
and Motor Vehicle Safety Act contains an express preemption provision:
When a motor vehicle safety standard is in effect under this chapter, a
State or a political subdivision of a State may prescribe or continue
in effect a standard applicable to the same aspect of performance of a
motor vehicle or motor vehicle equipment only if the standard is
identical to the standard prescribed under this chapter. 49 U.S.C.
30103(b)(1). It is this statutory command by Congress that preempts any
non-identical State legislative and administrative law addressing the
same aspect of performance.
The express preemption provision described above is subject to a
savings clause under which ``[c]ompliance with a motor vehicle safety
standard prescribed under this chapter does not exempt a person from
liability at common law.'' 49 U.S.C. 30103(e) Pursuant to this
provision, State common law tort causes of action against motor vehicle
manufacturers that might otherwise be preempted by the express
preemption provision are generally preserved. However, the Supreme
Court has recognized the possibility, in some instances, of implied
preemption of such State common law tort causes of action by virtue of
NHTSA's rules, even if not expressly preempted. This second way that
NHTSA rules can preempt is dependent upon there being an actual
conflict between an FMVSS and the higher standard that would
effectively be imposed on motor vehicle manufacturers if someone
obtained a State common law tort judgment against the manufacturer,
notwithstanding the manufacturer's compliance with the NHTSA standard.
Because most NHTSA standards established by an FMVSS are minimum
standards, a State common law tort cause of action that seeks to impose
a higher standard on motor vehicle manufacturers will generally not be
preempted. However, if and when such a conflict does exist--for
example, when the standard at issue is both a minimum and a maximum
standard--the State common law tort cause of action is impliedly
preempted. See Geier v. American Honda Motor Co., 529 U.S. 861 (2000).

[[Page 3295]]

Pursuant to Executive Order 13132 and 12988, NHTSA has considered
whether this rule could or should preempt State common law causes of
action. The agency's ability to announce its conclusion regarding the
preemptive effect of one of its rules reduces the likelihood that
preemption will be an issue in any subsequent tort litigation.
To this end, the agency has examined the nature (e.g., the language
and structure of the regulatory text) and objectives of today's rule
and finds that this rule, like many NHTSA rules, prescribes only a
minimum safety standard. As such, NHTSA does not intend that this rule
preempt state tort law that would effectively impose a higher standard
on motor vehicle manufacturers than that established by today's rule.
Establishment of a higher standard by means of State tort law would not
conflict with the minimum standard announced here. Without any
conflict, there could not be any implied preemption of a State common
law tort cause of action.

Executive Order 12778 (Civil Justice Reform)

With respect to the review of the promulgation of a new regulation,
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
4729, February 7, 1996) requires that Executive agencies make every
reasonable effort to ensure that the regulation: (1) Clearly specifies
the preemptive effect; (2) clearly specifies the effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct, while promoting simplification and burden reduction;
(4) clearly specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
Pursuant to this Order, NHTSA notes as follows.
The issue of preemption is discussed above in connection with E.O.
13132. NHTSA notes further that there is no requirement that
individuals submit a petition for reconsideration or pursue other
administrative proceedings before they may file suit in court.

Unfunded Mandates Reform Act

The Unfunded Mandates Reform Act of 1995 (UMRA) requires Federal
agencies to prepare a written assessment of the costs, benefits and
other effects of proposed or final rules that include a Federal mandate
likely to result in the expenditure by State, local or tribal
governments, in the aggregate, or by the private sector, of more than
$100 million in any one year ($100 million adjusted annually for
inflation, with base year of 1995). These effects are discussed earlier
in this preamble and in the FRIA.
UMRA also requires an agency issuing a final rule subject to the
Act to select the ``least costly, most cost-effective or least
burdensome alternative that achieves the objectives of the rule.'' The
preamble and the FRIA discuss several alternatives we considered, and
the resulting cost and benefits of various alternative countermeasures.
The alternatives considered were: (a) Exclusion of the front lower
corner of the front side window area (test point A1); (b) a component
test consisting of a single headform impact at the center of the side
window opening area; and, (c) a full-vehicle dynamic test to evaluate a
countermeasure's retention capability instead of the headform component
test. The countermeasures examined for alternatives (a) and (b) were
various levels of partial window coverage (``partial curtain''). We
also examined the potential countermeasure of a partial curtain in
combination with the installation of laminated glazing in the front
window openings to prevent ejections through test point A1 and the
lower gap (``partial curtain plus laminated glazing''). However, as
discussed in this preamble and in the FRIA, none of these alternatives
achieved the objectives of the alternative adopted today. The agency
believes that it has selected the least costly, most cost-effective and
least burdensome alternative that achieves the objectives of the
rulemaking.

National Environmental Policy Act

NHTSA has analyzed this final rule for the purposes of the National
Environmental Policy Act. The agency has determined that implementation
of this action would not have any significant impact on the quality of
the human environment.

Plain Language

Executive Order 12866 requires each agency to write all rules in
plain language. Application of the principles of plain language
includes consideration of the following questions:
Have we organized the material to suit the public's needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?
If you have any responses to these questions, please write to us
about them.

Paperwork Reduction Act (PRA)

Under the PRA of 1995, a person is not required to respond to a
collection of information by a Federal agency unless the collection
displays a valid OMB control number. The final rule contains a
collection of information, i.e., the phase-in reporting requirements,
requirements to place consumer information about the readiness
indicator and about the sensor in the vehicle owner's manual (S4.2.3),
and requirements for providing information to NHTSA about a rollover
sensor in a compliance test (S4.2.4). There is no burden to the general
public.
The collection of information would require manufacturers of
passenger cars and of trucks, buses and MPVs with a GVWR of 4,536 kg
(10,000 lb) or less, to annually submit a report, and maintain records
related to the report, concerning the number of such vehicles that meet
the ejection mitigation requirements of this FMVSS. The phase-in of the
test requirements would be completed approximately seven years after
publication of a final rule (eight years counting the 100 percent
credit year). The purpose of the reporting requirements is to aid the
agency in determining whether a manufacturer has complied with the
ejection mitigation requirements during the phase-in of those
requirements, including the manufacturer's use of advanced credits.
Under the PRA, the agency must publish a document in the Federal
Register providing a 60-day comment period and otherwise consult with
members of the public and affected agencies concerning each collection
of information. This was accomplished in the NPRM preceding this final
rule (74 FR 63225). The Office of Management and Budget (OMB) has
promulgated regulations describing what must be included in such a
document. Pursuant to OMB's regulations (5 CFR 320.8(d)), NHTSA sought
public comment on the following:
(1) Whether the collection of information is necessary for the
proper performance of the functions of the agency, including whether
the information will have practical utility;

[[Page 3296]]

(2) The accuracy of the agency's estimate of the burden of the
proposed collection of information, including the validity of the
methodology and assumptions used;
(3) How to enhance the quality, utility, and clarity of the
information to be collected; and,
(4) How to minimize the burden of the collection of information on
those who are to respond, including the use of appropriate automated,
electronic, mechanical, or other technological collection techniques or
other forms of information technology, e.g., permitting electronic
submission of responses.
We published our estimates of the burden to vehicle manufacturers,
as follows:
NHTSA estimated that there are 21 manufacturers of
passenger cars, multipurpose passenger vehicles, trucks, and buses with
a GVWR of 4,536 kg (10,000 lb) or less;
NHTSA estimated that the total annual reporting and
recordkeeping burden resulting from the collection of information is
1,260 hours;
NHTSA estimated that the total annual cost burden, in U.S.
dollars, will be $0. No additional resources would be expended by
vehicle manufacturers to gather annual production information because
they already compile this data for their own use.
NHTSA did not receive any comments on the above. Therefore, we are
submitting a request for OMB clearance of the collection of information
required under today's final rule.

National Technology Transfer and Advancement Act

Under the National Technology Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104-113), all Federal agencies and departments shall
use technical standards that are developed or adopted by voluntary
consensus standards bodies, using such technical standards as a means
to carry out policy objectives or activities determined by the agencies
and departments.
Voluntary consensus standards are technical standards (e.g.,
materials specifications, test methods, sampling procedures, and
business practices) that are developed or adopted by voluntary
consensus standards bodies, such as the International Organization for
Standardization (ISO) and the Society of Automotive Engineers. The
NTTAA directs us to provide Congress, through OMB, explanations when we
decide not to use available and applicable voluntary consensus
standards.
Commenters requested that the agency apply voluntary industry
standards SAE J2568--Intrusion Resistance of Safety Glazing Systems for
Road Vehicles or BSI AU 209--Vehicle Security. These industry standards
specify that after testing there must not be separation within the
glazing or between the glazing and vehicle body, which would allow for
passage of a 40 mm diameter sphere (40 mm gap test).
We studied the potential of applying these standards, but decided
against adopting them for several reasons. These standards provide
glazing intrusion resistance requirements from external impact
(outside-in) as opposed to ejection mitigation (inside-out).
Additionally, the requirements are not appropriate for vehicles with
only side curtain air bags, given that there is a time dependence
associated with a curtain's ejection mitigation performance. Once
deployed, the pressure in the air bag continuously decreases. The 16
km/h test is done at 6 seconds to assure that the pressure does not
decrease too quickly. It does not seem that the 40 mm gap test could be
done after the 6-second impact, in any timeframe which is related to
rollover and side impact ejections.
Further, there was no shown safety need for applying the suggested
standards. We cannot show that ejections that would not be prevented by
the primary 100-mm displacement requirement would be prevented by a
secondary 40-mm requirement. Also, it seemed that the 40-mm requirement
would indirectly require installation of advanced glazing. As discussed
in this preamble, the costs associated with advanced glazing
installations at the side windows covered by the standard adopted today
are substantial in comparison to a system only utilizing rollover
curtains. For these reasons, the agency did not accept the suggestions.

List of Subjects

49 CFR Part 571

Imports, Incorporation by reference, Motor vehicle safety,
Reporting and recordkeeping requirements, Tires.

49 CFR Part 585

Motor vehicle safety, Reporting and recordkeeping requirements.

In consideration of the foregoing, NHTSA amends 49 CFR parts 571
and 585 as set forth below.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for part 571 continues to read as follows:

Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50.

0
2. Section 571.5(b) is amended by adding, in alphabetical order, an
entry to the list of materials incorporated by reference, as follows:

Sec. 571.5 Matter incorporated by reference.

* * * * *
(b) * * *

------------------------------------------------------------------------

------------------------------------------------------------------------
``Parts List; Ejection Mitigation 571.226, S7.1.1
Headform Drawing Package,'' December
2010; ``Parts List and Drawings;
Ejection Mitigation Headform Drawing
Package,'' December 2010. Copies may
be obtained by contacting:
Reprographics Technologies, 9000
Virginia Manor Rd., Beltsville, MD
20705, telephone (301) 210-5600.
------------------------------------------------------------------------

* * * * *

0
3. Section 571.226 is added to read as follows:

Sec. 571.226 Standard No. 226; Ejection Mitigation.

S1. Purpose and Scope. This standard establishes requirements for
ejection mitigation systems to reduce the likelihood of complete and
partial ejections of vehicle occupants through side windows during
rollovers or side impact events.
S2. Application. This standard applies to passenger cars, and to
multipurpose passenger vehicles, trucks and buses with a gross vehicle
weight rating of 4,536 kg or less, except walk-in vans, modified roof
vehicles and convertibles. Also excluded from this standard are law
enforcement vehicles, correctional institution vehicles, taxis and
limousines, if they have a fixed security partition separating the 1st
and 2nd or 2nd and 3rd rows and if they are produced by more than one
manufacturer or are altered (within the meaning of 49 CFR 567.7).
S3. Definitions.
Ejection impactor means a device specified in S7.1 of this standard
that is a component of the ejection mitigation test device and is the
moving mass that strikes the ejection mitigation countermeasure.
Ejection impactor targeting point means the intersection of the y-
axis of the ejection headform and the outer surface of the ejection
headform.

[[Page 3297]]

Ejection mitigation countermeasure means a device or devices,
except seat belts, integrated into the vehicle that reduce the
likelihood of occupant ejection through a side window opening, and that
requires no action by the occupant for activation.
Ejection propulsion mechanism means a device that is a component of
the ejection mitigation test device consisting of a mechanism capable
of propelling the ejection impactor and constraining it to move along
its axis or shaft.
Limited-line manufacturer means a manufacturer that sells three or
fewer carlines, as that term is defined in 49 CFR 583.4, in the United
States during a production year.
Modified roof means the replacement roof on a motor vehicle whose
original roof has been removed, in part or in total.
Row means a set of one or more seats whose seat outlines do not
overlap with the seat outline of any other seats, when all seats are
adjusted to their rearmost normal riding or driving position, when
viewed from the side.
Seat outline means the outer limits of a seat projected laterally
onto a vertical longitudinal vehicle plane.
Side daylight opening means, other than a door opening, the locus
of all points where a horizontal line, perpendicular to the vehicle
vertical longitudinal plane, is tangent to the periphery of the
opening. The periphery includes surfaces 100 millimeters inboard of the
inside surface of the window glazing and 25 mm outboard of the outside
surface of the side glazing. The periphery excludes the following: any
flexible gasket material or weather stripping used to create a
waterproof seal between the glazing or door and the vehicle interior;
grab handles used to facilitate occupant egress and ingress; and any
part of a seat.
Small manufacturer means an original vehicle manufacturer that
produces or assembles fewer than 5,000 vehicles annually for sale in
the United States.
Target means the x-z plane projection of the ejection headform face
as shown in Figure 1.
Walk-in van means a special cargo/mail delivery vehicle that only
has a driver designated seating position. The vehicle has a sliding (or
folding) side door and a roof clearance that enables a person of medium
stature to enter the passenger compartment area in an up-right
position.
Zero displacement plane means, a vertical plane parallel to the
vehicle longitudinal centerline and tangent to the most outboard
surface of the ejection headform when the headform is aligned with an
impact target location and just touching the inside surface of a window
covering the side daylight opening.
S4. Phase-in, performance and other requirements.
S4.1 Phase-in requirements.
S4.1.1 Except as provided in S4.1.3 of this standard, a percentage
of each manufacturer's vehicle production, as specified in S8 of this
standard, manufactured on or after September 1, 2013 to August 31,
2017, shall meet the requirements of S4.2. Vehicles that are not
subject to the phase-in may be certified as meeting the requirements
specified in this standard.
S4.1.2 Except as provided in S4.1.3 of this section, each vehicle
manufactured on or after September 1, 2017 must meet the requirements
of S4.2 without use of advanced credits.
S4.1.3 Exceptions from the phase-in; special allowances.
(a) Vehicles produced by a small manufacturer and by a limited line
manufacturer are not subject to S4.1.1 of this standard, but are
subject to S4.1.2.
(b) Vehicles that are altered (within the meaning of 49 CFR 567.7)
before September 1, 2018, after having been previously certified in
accordance with part 567 of this chapter, and vehicles manufactured in
two or more stages before September 1, 2018, are not required to meet
the requirements of S4.2. Vehicles that are altered on or after
September 1, 2018, and vehicles that are manufactured in two or more
stages on or after September 1, 2018, must meet the requirements of
S4.2.
S4.2 Performance and other requirements.
S4.2.1 When the ejection propulsion mechanism propels the ejection
impactor into the impact target locations of each side daylight opening
of a vehicle according to the test procedures specified in S5 of this
standard, the most outboard surface of the ejection headform must not
displace more than 100 millimeters beyond the zero displacement plane.
S4.2.1.1 No vehicle shall use movable glazing as the sole means of
meeting the displacement limit of S4.2.1.
S4.2.1.2 Vehicles with an ejection mitigation countermeasure that
deploys in the event of a rollover must deploy the countermeasure for
the side daylight opening being tested according to the procedure
specified in S5 of this standard.
S4.2.1.3 If a side daylight opening contains no target locations,
the impact test of S4.2.1 is not performed on that opening.
S4.2.2 Vehicles that have an ejection mitigation countermeasure
that deploys in the event of a rollover must have a monitoring system
with a readiness indicator. The indicator shall monitor its own
readiness and must be clearly visible from the driver's designated
seating position. The same readiness indicator required by S4.5.2 of
FMVSS No. 208 may be used to meet the requirement. A list of the
elements of the system being monitored by the indicator shall be
included with the information furnished in accordance with S4.2.3.
S4.2.3 Written information.
(a) Vehicles with an ejection mitigation countermeasure that
deploys in the event of a rollover must be described as such in the
vehicle's owner manual or in other written information provided by the
vehicle manufacturer to the consumer.
(b) Vehicles that have an ejection mitigation countermeasure that
deploys in the event of a rollover must include in written information
a discussion of the readiness indicator required by S4.2.2, specifying
a list of the elements of the system being monitored by the indicator,
a discussion of the purpose and location of the telltale, and
instructions to the consumer on the steps to take if the telltale is
illuminated.
S4.2.4 Technical Documentation. For vehicles that have an ejection
mitigation countermeasure that deploys in the event of a rollover, the
vehicle manufacturer must make available to the agency, upon request,
the following information: A discussion of the sensor system used to
deploy the countermeasure, including the pertinent inputs to the
computer or calculations within the computer and how its algorithm uses
that information to determine if the countermeasure should be deployed.
S5. Test procedures.
S5.1 Demonstrate compliance with S4.2 of this standard in
accordance with the test procedures specified in this standard, under
the conditions of S6, using the equipment described in S7. In the
impact test described by these procedures, target locations are
identified (S5.2) and the zero displacement plane location is
determined (S5.3). The glazing is pre-broken, fully retracted or
removed prior to the impact test (S5.4). The countermeasure is
deployed, if applicable, and an ejection impactor (see S7.1) strikes
the countermeasure at the impact target locations, at the specified
speeds and times (S5.5). The lateral displacement of the ejection
impactor beyond the zero displacement plane is measured.

[[Page 3298]]

S5.2 Determination of impact target locations.
S5.2.1 Boundary of target location.
S5.2.1.1 Initial determination of offset line. Determine the
location of an offset-line within the side daylight opening by
projecting each point of the side daylight opening laterally onto a
vehicle vertical longitudinal plane. Move each point by 252
mm towards the center of the side daylight opening projection and
perpendicular to a line tangent to the projection at that point, while
maintaining the point on a vehicle vertical longitudinal plane.
S5.2.1.2 Rearmost limit of offset line.
(a) Seats fixed in a forward facing direction. Except as provided
in S5.2.1.2(b), if an offset line extends rearward of a transverse
vertical vehicle plane located behind the seating reference point at
the distance specified in 5.2.1.2(a)(1) or (2), the transverse vertical
vehicle plane defines the rearward edge of the offset line for the
purposes of determining target locations.
(1) For a vehicle with fewer than 3 rows--1,400 mm behind the
rearmost SgRP.
(2) For a vehicle with 3 or more rows--600 mm behind the 3rd row
SgRP.
(b) Seats not fixed in a forward facing direction. When the last
row seat adjacent to the opening, in the case of a vehicle with fewer
than 3 rows, or the 3rd row seat adjacent to the opening, in the case
of a vehicle with 3 or more rows, is not fixed in the forward facing
direction, the offset line may extend farther rearward than specified
in S5.2.1.2(a) under the following conditions. With the seat in any
non-forward facing orientation, the seat back set at an inclination
position closest to the manufacturer's design seat back angle, and all
other seat adjustments at any possible position of adjustment,
determine the location of a vertical transverse vehicle plane located
behind the portion of the seat rearmost in the vehicle, at the distance
specified in 5.2.1.2(b)(1) and (2). The boundary of target locations
extends to this vertical plane if it is farther rearward than the plane
determined in S5.2.1.2(a).
(1) For a vehicle with fewer than 3 rows--1,400 mm behind the
portion of the seat rearmost in the vehicle.
(2) For a vehicle with 3 or more rows--600 mm behind the portion of
the seat rearmost in the vehicle, for a seat in the 3rd row.
(c) Vehicles with partitions or bulkheads. If a vehicle has a fixed
traverse partition or bulkhead through which there is no occupant
access and behind which there are no designated seating positions, a
vertical transverse vehicle plane 25 mm forward of the most forward
portion of the partition or bulkhead defines the rearward edge of the
offset line for the purposes of determining target locations when said
plane is forward of the limiting plane defined in S5.2.1.2(a) or (b).
S5.2.2 Preliminary target locations.
(a) To identify the impact target locations, the following
procedures are performed with the x and z axes of the target, shown in
Figure 1 (provided for illustration purposes), aligned within 1 degree of the vehicle longitudinal and vertical axes,
respectively, and the target y axis pointing in the outboard direction.
(b) Place targets at any location inside the offset-line where the
target is tangent to within 2 mm of the offset-line at just
two or three points (see Figure 2) (figure provided for illustration
purposes).
S5.2.3 Determination of primary target locations. Divide the side
daylight opening into four quadrants by passing a vertical line and a
horizontal line, in a vehicle vertical longitudinal plane, through the
geometric center of the side daylight opening.
S5.2.3.1 Front windows. For any side daylight opening forward of
the vehicle B-pillar, the primary quadrants are the forward-lower and
rearward-upper.
S5.2.3.2 Rear windows. For any side daylight opening rearward of
the B-pillar, the primary quadrants are the forward-upper and rearward-
lower.
S5.2.3.3 If a primary quadrant contains only one target center,
that target is the primary target for that quadrant (see Figure 3)
(figure provided for illustration purposes). If there is more than one
target center in a primary quadrant, the primary target for that
quadrant is the lowest target in a lower quadrant and the highest
target in an upper quadrant. If there is a primary quadrant that does
not contain a target center, the target center closest to the primary
quadrant outline is the primary target.
S5.2.4 Determination of secondary target locations.
S5.2.4.1 Front windows. Measure the horizontal distance between the
centers of the primary targets. For a side daylight opening forward of
the B-pillar, place one secondary target center rearward of the forward
primary target by one-third of the horizontal distance between the
primary target centers and tangent with upper portion of the offset-
line. Place another secondary target center rearward of the forward
primary target by two-thirds of the horizontal distance between the
primary target centers and tangent with the lower portion of the
offset-line (see figure 4) (figure provided for illustration purposes).
S5.2.4.2 Rear windows. For side daylight openings rearward of the
B-pillar, place one secondary target center rearward of the forward
primary target by one-third of the horizontal distance between the
primary target centers and tangent with lower portion of the offset-
line. Place another secondary target center rearward of the forward
primary target by two-thirds of the horizontal distance between the
primary target centers and tangent with the upper portion of the
offset-line (see Figure 4) (figure provided for illustration purposes).
S5.2.5 Target adjustment.
S5.2.5.1 Target elimination and reconstitution.
S5.2.5.1.1 Target elimination. Determine the horizontal and
vertical distance between the centers of the targets. If the minimum
distance between the z axes of the targets is less than 135 mm and the
minimum distance between the x axes of the targets is less than 170 mm,
eliminate the targets in the order of priority given in steps 1 through
4 of Table 1 (see Figure 5) (figure provided for illustration
purposes). In each case, both the z axes of the targets must be closer
than 135 mm and x axes of the targets must be closer than 170 mm. If
the minimum distance between the z axes of the targets is not less than
135 mm or the minimum distance between the y axes of the targets is not
less than 170 mm, do not eliminate the target. Continue checking all
the targets listed in steps 1 through 4 of Table 1.

Table 1--Priority List of Target Distance To Be Checked Against Limits
------------------------------------------------------------------------
Eliminate this target if
distances between z axes
Measure distance from z of targets and x axes of
Step axis to z axis and x axis targets are less than 135
to x axis for these targets mm and 170 mm,
respectively
------------------------------------------------------------------------
1.............. Upper Secondary to Lower Upper Secondary.
Secondary.
2.............. Upper Primary to Upper or Upper or Remaining
Remaining Secondary. Secondary.

[[Page 3299]]

3.............. Lower Primary to Lower or Lower or Remaining
Remaining Secondary. Secondary.
4.............. Upper Primary to Lower Upper Primary.
Primary.
------------------------------------------------------------------------

S5.2.5.1.2 Target reconstitution. If after following the procedure
given in S5.2.5.1.1, there are only two targets remaining, determine
the absolute distance between the centers of these targets. If this
distance is greater than or equal to 360 mm, place a target such that
its center bisects a line connecting the centers of the remaining
targets.
S5.2.5.2 Target reorientation--90 degree rotation. If after
following the procedure given in S5.2.5.1 there are less than four
targets in a side daylight opening, repeat the procedure in 5.2 through
5.2.5.1.2, with a modification to S5.2 as follows. Reorient the target
by rotating it 90 degrees about the y axis of the target such that the
target positive z axis is aligned within 1 degree of the
vehicle longitudinal axis, pointing in the direction of the vehicle
positive x axis. If after performing the procedure in this section, the
remaining targets exceed the number of targets determined with the
original orientation of the target, the reoriented targets represent
the final target locations for the side daylight opening.
S5.2.5.3 Target reorientation--incremental rotation. If after
following the procedure given in S5.2.5.2 there are no targets in a
side daylight opening, starting with the target in the position defined
in S5.2.2.2(a), reorient the target by rotating it in 5 degree
increments about the y axis of the target by rotating the target
positive z axis toward the vehicle positive x axis. At each increment
of rotation, attempt to fit the target within the offset line of the
side daylight opening. At the first increment of rotation where the
target will fit, place the target center as close as possible to the
geometric center of the side daylight opening. If more than one
position exists that is closest to the geometric center of the side
daylight opening, select the lowest.
S5.3 Determination of zero displacement plane. The glazing covering
the target location of the side daylight opening being tested is intact
and in place in the case of fixed glazing and intact and fully closed
in the case of movable glazing. With the ejection impactor targeting
point aligned within 2 mm of the center of any target
location specified in S5.2, and with the ejection impactor on the
inside of the vehicle, slowly move the impactor towards the window
until contact is made with the interior of the glazing with no more
than 20 N of pressure being applied to the window. The location of the
most outboard surface of the headform establishes the zero displacement
plane for this target location.
S5.4 Window position and condition.Subject to S5.5(b), prior to
impact testing, the glazing covering the target location must be
removed from the side daylight opening, fully retracted, or pre-broken
according to the procedure in S5.4.1, at the vehicle manufacturer's
option.
S5.4.1 Window glazing pre-breaking procedure.
S5.4.1.1 Breakage pattern. Locate the geometric center of the side
daylight opening, established in S5.2.3 of this standard. Mark the
outside surface of the window glazing in a horizontal and vertical grid
of points separated by 752 mm with one point coincident
within 2 mm of the geometric center of the side daylight
opening (see Figure 6) (figure provided for illustration purposes).
Mark the inside surface of the window glazing in a horizontal and
vertical grid of points separated by 752 mm with the entire
grid horizontally offset by 37.5 2 mm from the grid of
points on the outside of the glazing.
S5.4.1.2 Breakage method.
(a) Start with the inside surface of the window and forward-most,
lowest mark made as specified in S5.4.1.1 of this standard. Use a
center punch in this procedure. The punch tip has a 5 2 mm
diameter prior to coming to a point. The spring is adjusted to require
150 25 N of force to activate the punch. Only once at each
mark location, apply pressure to activate the spring in the center
punch in a direction which is perpendicular to the tangent of the
window surface at the point of contact, within 10 degrees.
Apply the pressure only once at each mark location, even if the glazing
does not break or no hole results.
(b) Use a 100 10 mm x 100 10 mm piece of
plywood with a minimum thickness of 18 mm as a reaction surface on the
opposite side of the glazing to prevent to the extent possible the
window surface from deforming by more than 10 mm when pressure is being
applied to the hole-punch.
(c) Continue the procedure with the center punch by moving rearward
in the grid until the end of a row is reached. When the end of a row is
reached, move to the forward-most mark on the next higher row and
continue the procedure. Continue in this pattern until the procedure is
conducted at each marked location on the inside surface of the glazing.
(d) Repeat the process on the outside surface of the window.
(e) If punching a hole causes the glazing to disintegrate, halt the
breakage procedure and proceed with the headform impact test.
S5.5 Impact speeds and time delays. The ejection impactor speeds
specified below must be achieved after propulsion has ceased.
(a) Vehicles with or without an ejection mitigation countermeasure
that deploys in a rollover. For a vehicle with an ejection mitigation
countermeasure that deploys in a rollover, using the ejection
propulsion mechanism, propel the ejection impactor such that it first
strikes the countermeasure, while aligned with any target location
specified in S5.2 of this standard, 1.5 0.1 seconds after
activation of the ejection mitigation countermeasure that deploys in
the event of a rollover, and at a speed of 20 0.5 km/h. For
a vehicle without an ejection mitigation countermeasure that deploys in
a rollover, propel the ejection impactor at any time such that it first
strikes the countermeasure, while aligned with any target location
specified in S5.2 of this standard, at a speed of 20 0.5
km/h.
(b) Vehicles with an ejection mitigation countermeasure that
deploys in a rollover. For a vehicle with an ejection mitigation
countermeasure that deploys in a rollover, remove or fully retract any
movable glazing from the side daylight opening. Using the ejection
propulsion mechanism, propel the ejection impactor such that it first
strikes the countermeasure, while aligned with any target location
specified in S5.2 of this standard, 6.0 0.1 seconds after
activation of an ejection mitigation countermeasure that deploys in the
event of a rollover, and at a speed of 16 0.5 km/h.
(c) An ejection mitigation countermeasure that deploys in the event
of a rollover is described as such

[[Page 3300]]

in the vehicle's owner manual or in other written information provided
by the vehicle manufacturer to the consumer.
S5.6 Ejection impactor orientation.
S5.6.1 If the targets for the side daylight opening being impacted
were determined by the procedure specified in S5.2.2 through S5.2.5.1
only, the ejection impactor orientation is as follows. At the time of
launch of the ejection impactor the x, y and z axes of the ejection
headform must be aligned within 1 degree of the vehicle
longitudinal, transverse and vertical axes, respectively.
S5.6.2 If the targets for the side daylight opening being impacted
were determined by the procedure specified in S5.2.5.2, the ejection
impactor orientation is as follows. At the time of launch the ejection
impactor is rotated by 90 degrees about the ejection headform y axis,
from the orientation specified in S5.6.1, resulting in the headform
positive z axis pointing in the direction of the vehicle positive x
axis.
S5.6.3 If the targets for the side daylight opening being impacted
were determined by the procedure specified in S5.2.5.3, the ejection
impactor orientation is as follows. At the time of launch the ejection
impactor is rotated about the y axis of the ejection headform by
rotating the headform positive z axis towards the vehicle positive x
axis, in the increment determined to be necessary in S5.2.5.3 to fit
the target within the side daylight opening.
S5.6.4 After any test, extend the ejection impactor to the zero
plane and determine that x, y and z axes of the ejection headform
remain aligned within 1 degree of its orientation at launch
as specified in S5.6.1--5.6.3.
S6 General test conditions.
S6.1 Vehicle test attitude. The vehicle is supported off its
suspension at an attitude determined in accordance with S6.1(a) through
(e).
(a) The vehicle is loaded to its unloaded vehicle weight.
(b) All tires are inflated to the manufacturer's specifications
listed on the vehicle's tire placard.
(c) Place vehicle on a level surface.
(c) Pitch: Measure the sill angle of the driver door sill and mark
where the angle is measured.
(d) Roll: Mark a point on the vehicle body above the left and right
front wheel wells. Determine the vertical height of these two points
from the level surface.
(e) Support the vehicle off its suspension such that the driver
door sill angle is within 1 degree of that measured at the
marked area in S6.1(c) and the vertical height difference of the two
points marked in S6.1(d) is within 5 mm of the vertical
height difference determined in S6.1(d).
S6.2 Doors.
(a) Except as provided in S6.2(b) or S6.2(c), doors, including any
rear hatchback or tailgate, are fully closed and latched but not
locked.
(b) During testing, any side door on the opposite side of the
longitudinal centerline of the vehicle from the target to be impacted
may be open or removed.
(c) During testing, any rear hatchback or tailgate may be open or
removed for testing any target.
S6.3 Steering wheel, steering column, seats, grab handles, and
exterior mirrors. During targeting and testing, the steering wheel,
steering column, seats, grab handles and exterior mirrors may be
removed from the vehicle or adjusted to facilitate testing and/or
provide an unobstructed path for headform travel through and beyond the
vehicle.
S6.4 Other vehicle components and structures. During targeting and
testing, interior vehicle components and vehicle structures other than
specified in S6.2 and S6.3 may be removed or adjusted to the extent
necessary to allow positioning of the ejection propulsion mechanism and
provide an unobstructed path for the headform travel through and beyond
the vehicle.
S6.5 Temperature and humidity.
(a) During testing, the ambient temperature is between 18 degrees
C. and 29 degrees C., at any relative humidity between 10 percent and
70 percent.
(b) The headform specified in S7.1.1 of this standard is exposed to
the conditions specified in S6.5(a) for a continuous period not less
than one hour, prior to the test.
S7. Ejection mitigation test device specifications. The ejection
mitigation test device consists of an ejection impactor and ejection
propulsion mechanism with the following specifications. The ability of
a test device to meet these specifications may be determined outside of
the vehicle.
S7.1 Ejection impactor. The ejection impactor consists of an
ejection headform attached to a shaft. The ejection impactor has a mass
of 18 kg 0.05 kg. The shaft is parallel to the y axis of
the headform.
S7.1.1 Ejection headform dimensions. The ejection headform has the
dimensions shown in Figure 1 and is depicted in the ``Parts List;
Ejection Mitigation Headform Drawing Package,'' December 2010, and the
``Parts List and Drawings; Ejection Mitigation Headform Drawing
Package,'' December 2010 (incorporated by reference; see Sec. 571.5).
S7.2 Static deflection. The ejection impactor targeting point must
not deflect more than 20 mm in the x-z plane when a 981 N
5 N force is applied in a vehicle vertical longitudinal plane, through
the y axis of the headform and no more than 5 mm rear of the posterior
surface of the headform. The force is applied once in each of the
following headform axes: +z, -z, +x, -x. The static deflection
measurement is made with the ejection impactor extended 400 mm outboard
of the theoretical point of impact with the countermeasure and attached
to the ejection propulsion mechanism, including any support frame and
anchors.
S7.3 Frictional characteristics.
(a) Measure the dynamic coefficient of friction of the ejection
impactor and any associated bearings and bearing housing in a test
ready orientation. Repeat the measurement in three more orientations
with the ejection impactor and any associated bearings and bearing
housing rotated 90, 180 and 270 degrees about the headform y axis.
Perform the measurement five consecutive times at each orientation.
(b) Measure the average force necessary to move the ejection
impactor 200 mm rearward into the ejection propulsion mechanism at a
rate of 50 (13) mm per second, starting at a point 400 mm
outboard of the theoretical point of impact with the countermeasure.
Measure the force to an accuracy of 5 N. The measurement
excludes the force measured over the first 25 mm of travel and is
recorded at a minimum frequency of 100 Hz. During the test a 100 kg
0.5 kg mass is attached to the impactor with its center of
gravity passing through the axis of motion of the impactor and no more
than 5 mm rear of the posterior surface of the headform.
(c) Take the five force level averages made at each impactor
orientation in S7.3(a) and average them. Take the maximum of the force
average values and divide by 9.81 times the combined mass of the
ejection impactor and mass added in S7.3(b). The resulting value must
not exceed 0.25.
S7.4 Targeting accuracy. Determine the distance ``D'' along the
axis of travel of the ejection impactor from its launch point to the
theoretical point of impact with the countermeasure, when moving at the
speed specified in S5.5. Determine that the ejection mitigation test
device can deliver the ejection impactor targeting point to within
10 mm of an axis normal to and passing through the target
center, as the unobstructed impactor passes through a zone defined by
vertical longitudinal

[[Page 3301]]

planes 50 mm forward and rearward of ``D.''
S8 Phase-in Schedule for Vehicle Certification.
S8.1 Vehicles manufactured on or after September 1, 2013 and before
September 1, 2016. At anytime during the production years ending August
31, 2014, August 31, 2015, and August 31, 2016, each manufacturer
shall, upon request from the Office of Vehicle Safety Compliance,
provide information identifying the vehicles (by make, model and
vehicle identification number) that have been certified as complying
with this standard. The manufacturer's designation of a vehicle as a
certified vehicle is irrevocable.
S8.2 Vehicles manufactured on or after September 1, 2013 and before
September 1, 2014. Subject to S8.9, for vehicles manufactured on or
after September 1, 2013 and before September 1, 2014, the number of
vehicles complying with S4.2 shall be not less than 25 percent of:
(a) The manufacturer's average annual production of vehicles
manufactured in the three previous production years; or
(b) The manufacturer's production in the current production year.
S8.4 Vehicles manufactured on or after September 1, 2015 and before
September 1, 2016. Subject to S8.9, for vehicles manufactured on or
after September 1, 2015 and before September 1, 2016, the number of
vehicles complying with S4.2 shall be not less than 75 percent of:
(a) The manufacturer's average annual production of vehicles
manufactured in the three previous production years; or
(b) The manufacturer's production in the current production year.
S8.5 Vehicles manufactured on or after September 1, 2016 and before
September 1, 2017. Subject to S8.9, for vehicles manufactured on or
after September 1, 2016 and before September 1, 2017, the number of
vehicles complying with S4.2 shall be not less than 100 percent of the
manufacturer's production in the current production year.
8.6 Vehicles produced by more than one manufacturer. For the
purpose of calculating average annual production of vehicles for each
manufacturer and the number of vehicles manufactured by each
manufacturer under S8.1 through S8.4, a vehicle produced by more than
one manufacturer shall be attributed to a single manufacturer as
follows, subject to S8.7.
(a) A vehicle that is imported shall be attributed to the importer.
(b) A vehicle manufactured in the United States by more than one
manufacturer, one of which also markets the vehicle, shall be
attributed to the manufacturer that markets the vehicle.
S8.7 A vehicle produced by more than one manufacturer shall be
attributed to any one of the vehicle's manufacturers specified by an
express written contract, reported to the National Highway Traffic
Safety Administration under 49 CFR part 585, between the manufacturer
so specified and the manufacturer to which the vehicle would otherwise
be attributed under S8.5.
S8.8 For the purposes of calculating average annual production of
vehicles for each manufacturer and the number of vehicles manufactured
by each manufacturer under S8, do not count any vehicle that is
excluded by this standard from the requirements.
S8.9 Calculation of complying vehicles.
(a) For the purposes of calculating the vehicles complying with
S8.2, a manufacturer may count a vehicle if it is manufactured on or
after March 1, 2011 but before September 1, 2014.
(b) For purposes of complying with S8.3, a manufacturer may count a
vehicle if it--
(1) Is manufactured on or after March 1, 2011 but before September
1, 2015 and,
(2) Is not counted toward compliance with S8.2.
(c) For purposes of complying with S8.4, a manufacturer may count a
vehicle if it--
(1) Is manufactured on or after March 1, 2011 but before September
1, 2016 and,
(2) Is not counted toward compliance with S8.2 or S8.3.
(d) For purposes of complying with S8.5, a manufacturer may count a
vehicle if it--
(1) Is manufactured on or after March 1, 2011 but before September
1, 2017 and,
(2) Is not counted toward compliance with S8.2, S8.3, or S8.4.
(e) For the purposes of calculating average annual production of
vehicles for each manufacturer and the number of vehicles manufactured
by each manufacturer, each vehicle that is excluded from having to meet
this standard is not counted.

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0
4. The authority citation for part 585 continues to read as follows:

Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.50.

0
5. Part 585 is amended by adding Subpart K to read as follows:

PART 585--PHASE-IN REPORTING REQUIREMENTS

* * * * *
Subpart K--Ejection Mitigation Phase-in Reporting Requirements
585.100 Scope.
585.101 Purpose.
585.102 Applicability.
585.103 Definitions.
585.104 Response to inquiries.
585.105 Reporting requirements.
585.106 Records.

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Subpart K--Ejection Mitigation Phase-in Reporting Requirements

Sec. 585.100 Scope.

This part establishes requirements for manufacturers of passenger
cars, and of trucks, buses and multipurpose passenger vehicles with a
gross vehicle weight rating (GVWR) of 4,536 kilograms (kg) (10,000
pounds (lb)) or less, to submit a report, and maintain records related
to the report, concerning the number of such vehicles that meet the
ejection mitigation requirements of Standard No. 226, Ejection
Mitigation (49 CFR 571.226).

Sec. 585.101 Purpose.

The purpose of these reporting requirements is to assist the
National Highway Traffic Safety Administration in determining whether a
manufacturer has complied with the requirements of Standard No. 226,
Ejection Mitigation (49 CFR 571.226).

Sec. 585.102 Applicability.

This part applies to manufacturers of passenger cars, and of
trucks, buses and multipurpose passenger vehicles with a GVWR of 4,536
kg (10,000 lb) or less. However, this subpart does not apply to
vehicles excluded by Standard No. 226 (49 CFR 571.226) from the
requirements of that standard. This subpart does not apply to
manufacturers whose production consists exclusively of vehicles
manufactured in two or more stages, to manufacturers whose production
of motor vehicles for the United States market is less than 5,000
vehicles in a production year, and to limited line manufacturers.

Sec. 585.103 Definitions.

(a) All terms defined in 49 U.S.C. 30102 are used in their
statutory meaning.
(b) Bus, gross vehicle weight rating or GVWR, multipurpose
passenger vehicle, passenger car, and truck are used as defined in
Sec. 571.3 of this chapter.
(c) Production year means the 12-month period between September 1
of one year and August 31 of the following year, inclusive.
(d) Limited line manufacturer means a manufacturer that sells three
or fewer carlines, as that term is defined in 49 CFR 583.4, in the
United States during a production year.

Sec. 585.104 Response to inquiries.

At anytime during the production years ending August 31, 2014,
August 31, 2015, August 31, 2016, and August 31, 2017, each
manufacturer shall, upon request from the Office of Vehicle Safety
Compliance, provide information identifying the vehicles (by make,
model and vehicle identification number) that have been certified as
complying with the ejection mitigation requirements of Standard No.
226, Ejection mitigation (49 CFR 571.226). The manufacturer's
designation of a vehicle as a certified vehicle is irrevocable.

Sec. 585.105 Reporting requirements.

(a) Advanced credit phase-in reporting requirements. (1) Within 60
days after the end of the production years ending August 31, 2011,
through August 31, 2017, each manufacturer certifying vehicles
manufactured during any of those production years as complying with the
ejection mitigation requirements of Standard No. 226 (49 CFR 571.226)
shall submit a report to the National Highway Traffic Safety
Administration providing the information specified in paragraph (c) of
this section and in Sec. 585.2 of this part.
(b) Phase-in reporting requirements. Within 60 days after the end
of each of the production years ending August 31, 2014, through August
31, 2017, each manufacturer shall submit a report to the National
Highway Traffic Safety Administration concerning its compliance with
the ejection mitigation requirements of Standard No. 226 (49 CFR
571.226) for its vehicles produced in that year. Each report shall
provide the information specified in paragraph (d) of this section and
in Sec. 585.2 of this part.
(c) Advanced credit phase-in report content--(1) Production of
complying vehicles. With respect to the reports identified in Sec.
585.105(a), each manufacturer shall report for the production year for
which the report is filed the number of vehicles, by make and model
year, that are certified as meeting the ejection mitigation
requirements of Standard No. 226 (49 CFR 571.226).
(d) Phase-in report content--
(1) Basis for phase-in production goals. Each manufacturer shall
provide the number of passenger cars, multipurpose passenger vehicles,
trucks, and buses, with a gross vehicle weight rating of 4,536
kilograms (10,000 pounds) or less, manufactured in the current
production year, or, at the manufacturer's option, in each of the three
previous production years. A new manufacturer that is, for the first
time, manufacturing these vehicles for sale in the United States must
report the number of these vehicles manufactured during the current
production year.
(2) Production of complying vehicles. Each manufacturer shall
report for the production year being reported on information on the
number of passenger cars, multipurpose passenger vehicles, trucks, and
buses, with a gross vehicle weight rating of 4,536 kilograms (10,000
pounds) or less that meet the ejection mitigation requirements of
Standard No. 226 (49 CFR 571.226). The manufacturer shall report the
vehicles produced during the preceding years for which the manufacturer
is claiming credits as having been produced during the production year
being reported on.

Sec. 585.106 Records.

Each manufacturer shall maintain records of the Vehicle
Identification Number for each vehicle for which information is
reported under Sec. 585.105 until December 31, 2020.

Issued on January 5, 2011.
David L. Strickland,
Administrator.
[FR Doc. 2011-547 Filed 1-13-11; 8:45 am]
BILLING CODE 4910-59-P