[Code of Federal Regulations]
[Title 49, Volume 5]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR523.2]

[Page 83-84]
 
                        TITLE 49--TRANSPORTATION
 
                            OF TRANSPORTATION
 
PART 523--VEHICLE CLASSIFICATION--Table of Contents
 
Sec. 523.2  Definitions.

    Approach angle means the smallest angle, in a plane side view of an 
automobile, formed by the level surface on which the automobile is 
standing and a line tangent to the front tire static loaded radius arc 
and touching the underside of the automobile forward of the front tire.
    Axle clearance means the vertical distance from the level surface on 
which an automobile is standing to the lowest point on the axle 
differential of the automobile.
    Basic vehicle frontal area is used as defined in 40 CFR 86.079-2.

[[Page 84]]

    Breakover angle means the supplement of the largest angle, in the 
plan side view of an automobile, that can be formed by two lines tangent 
to the front and rear static loaded radii arcs and intersecting at a 
point on the underside of the automobile.
    Cargo-carrying volume means the luggage capacity or cargo volume 
index, as appropriate, and as those terms are defined in 40 CFR 600.315, 
in the case of automobiles to which either of those terms apply. With 
respect to automobiles to which neither of those terms apply ``cargo-
carrying volume'' means the total volume in cubic feet rounded to the 
nearest 0.1 cubic feet of either an automobile's enclosed nonseating 
space that is intended primarily for carrying cargo and is not 
accessible from the passenger compartment, or the space intended 
primarily for carrying cargo bounded in the front by a vertical plane 
that is perpendicular to the longitudinal centerline of the automobile 
and passes through the rearmost point on the rearmost seat and elsewhere 
by the automobile's interior surfaces.
    Curb weight is defined the same as vehicle curb weight in 40 CFR 
part 86.
    Departure angle means the smallest angle, in a plane side view of an 
automobile, formed by the level surface on which the automobile is 
standing and a line tangent to the rear tire static loaded radius arc 
and touching the underside of the automobile rearward of the rear tire.
    Gross vehicle weight rating means the value specified by the 
manufacturer as the loaded weight of a single vehicle.
    Passenger-carrying volume means the sum of the front seat volume 
and, if any, rear seat volume, as defined in 40 CFR 600.315, in the case 
of automobiles to which that term applies. With respect to automobiles 
to which that term does not apply, ``passenger-carrying volume'' means 
the sum in cubic feet, rounded to the nearest 0.1 cubic feet, of the 
volume of a vehicle's front seat and seats to the rear of the front 
seat, as applicable, calculated as follows with the head room, shoulder 
room, and leg room dimensions determined in accordance with the 
procedures outlined in Society of Automotive Engineers Recommended 
Practice J1100a, Motor Vehicle Dimensions (Report of Human Factors 
Engineering Committee, Society of Automotive Engineers, approved 
September 1973 and last revised September 1975).
    (a) For front seat volume, divide 1,728 into the product of the 
following SAE dimensions, measured in inches to the nearest 0.1 inches, 
and round the quotient to the nearest 0.001 cubic feet.
    (1) H61-Effective head room--front.
    (2) W3-Shoulder room--front.
    (3) L34-Maximum effective leg room-accelerator.
    (b) For the volume of seats to the rear of the front seat, divide 
1,728 into the product of the following SAE dimensions, measured in 
inches to the nearest 0.1 inches, and rounded the quotient to the 
nearest 0.001 cubic feet.
    (1) H63-Effective head room--second.
    (2) W4-Shoulder room--second.
    (3) L51-Minimum effective leg room--second.
    Running clearance means the distance from the surface on which an 
automobile is standing to the lowest point on the automobile, excluding 
unsprung weight.
    Static loaded radius arc means a portion of a circle whose center is 
the center of a standard tire-rim combination of an automobile and whose 
radius is the distance from that center to the level surface on which 
the automobile is standing, measured with the automobile at curb weight, 
the wheel parallel to the vehicle's longitudinal centerline, and the 
tire inflated to the manufacturer's recommended pressure.
    Temporary living quarters means a space in the interior of an 
automobile in which people may temporarily live and which includes 
sleeping surfaces, such as beds, and household conveniences, such as a 
sink, stove, refrigerator, or toilet.

(Sec. 9, Pub. L. 89-670, 80 Stat. 981 (49 U.S.C. 1657); sec. 301, Pub. 
L. 94-163, 89 Stat. 901 (15 U.S.C. 2002); delegation of authority at 41 
FR 25015, June 22, 1976)

[42 FR 38362, July 28, 1977, as amended at 43 FR 12013, Mar. 23, 1978]