[Code of Federal Regulations]
[Title 23, Volume 1]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 23CFR658.5]

[Page 278-280]
 
                           TITLE 23--HIGHWAYS
 
 CHAPTER I--FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
 
PART 658_TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS_LENGTH, WIDTH AND 
 
Sec.  658.5  Definitions.

    Automobile transporters. Any vehicle combination designed and used 
specifically for the transport of assembled highway vehicles, including 
truck camper units.
    Beverage semitrailer. A van-type, drop-frame semitrailer designed 
and used specifically for the transport and delivery of bottled or 
canned beverages (i.e., liquids for drinking, including water) which has 
side-only access for loading and unloading this commodity. Semitrailer 
has the same meaning as in 49 CFR 390.5.
    Boat transporters. Any vehicle combination designed and used 
specifically to transport assembled boats and boat hulls. Boats may be 
partially disassembled to facilitate transporting.
    Bridge gross weight formula. The standard specifying the 
relationship between axle (or groups of axles) spacing and the gross 
weight that (those) axle(s) may carry expressed by the formula:
[GRAPHIC] [TIFF OMITTED] TC14OC91.011

where W=overall gross weight on any group of two or more consecutive 
axles to the nearest 500 pounds, L=distance in feet between the extreme 
of any group of two or more consecutive axles, and N=number of axles in 
the group under consideration.

    Cargo-carrying unit. As used in this part, cargo-carrying unit means 
any portion of a commercial motor vehicle (CMV) combination (other than 
a truck tractor) used for the carrying of cargo, including a trailer, 
semitrailer, or the cargo-carrying section of a single-unit truck. The 
length of the cargo carrying units of a CMV with two or more such units 
is measured from the front of the first unit to the rear of the last 
[including the hitch(es) between the units].
    Commercial motor vehicle. For purposes of this regulation, a motor 
vehicle designed or regularly used to carry freight, merchandise, or 
more than ten passengers, whether loaded or empty, including buses, but 
not including vehicles used for vanpools, or recreational vehicles 
operating under their own power.
    Drive-away saddlemount vehicle transporter combination. The term 
drive-away saddlemount vehicle transporter combination means a vehicle 
combination designed and specifically used to tow up to 3 trucks or 
truck tractors, each connected by a saddle to the frame or fifth wheel 
of the forward vehicle of the truck tractor in front of it. Such 
combinations may include up to one fullmount.
    Dromedary unit. A box, deck, or plate mounted behind the cab and 
forward of the fifth wheel on the frame of the power unit of a truck 
tractor-semitrailer combination.
    Federal-aid Primary System. The Federal-aid Highway System of rural 
arterials and their extensions into or through urban areas in existence 
on June 1, 1991, as described in 23 U.S.C. 103(b) in effect at that 
time.
    Fullmount. A fullmount is a smaller vehicle mounted completely on 
the frame of either the first or last vehicle in a saddlemount 
combination.
    Interstate System. The National System of Interstate and Defense 
Highways described in sections 103(e) and 139(a) of Title 23, U.S.C. For 
the purpose of this regulation this system includes toll roads 
designated as Interstate.
    Length exclusive devices. Devices excluded from the measurement of 
vehicle length. Such devices shall not be designed or used to carry 
cargo.
    Longer combination vehicle (LCV). As used in this part, longer 
combination vehicle means any combination of a truck tractor and two or 
more trailers or semitrailers which operates on the Interstate System at 
a gross vehicle weight greater than 80,000 pounds.
    Maxi-cube vehicle. A maxi-cube vehicle is a combination vehicle 
consisting of a power unit and a trailing unit, both of which are 
designed to carry cargo. The power unit is a nonarticulated truck with 
one or more drive axles that carries either a detachable or a 
permanently attached cargo box.

[[Page 279]]

The trailing unit is a trailer or semitrailer with a cargo box so 
designed that the power unit may be loaded and unloaded through the 
trailing unit. Neither cargo box shall exceed 34 feet in length, 
excluding drawbar or hitching device; the distance from the front of the 
first to the rear of the second cargo box shall not exceed 60 feet, 
including the space between the cargo boxes; and the overall length of 
the combination vehicle shall not exceed 65 feet, including the space 
between the cargo boxes.
    Motor carrier of passengers. As used in this part, a motor carrier 
of passengers is a common, contract, or private carrier using a bus to 
provide commercial transportation of passengers. Bus has the same 
meaning as in 49 CFR 390.5.
    National Network (NN). The composite of the individual network of 
highways from each State on which vehicles authorized by the provisions 
of the STAA are allowed to operate. The network in each State includes 
the Interstate System, exclusive of those portions excepted under Sec.  
658.11(f) or deleted under Sec.  658.11(d), and those portions of the 
Federal-aid Primary System in existence on June 1, 1991, set out by the 
FHWA in appendix A to this part.
    Nondivisible load or vehicle.
    (1) As used in this part, nondivisible means any load or vehicle 
exceeding applicable length or weight limits which, if separated into 
smaller loads or vehicles, would:
    (i) Compromise the intended use of the vehicle, i.e., make it unable 
to perform the function for which it was intended;
    (ii) Destroy the value of the load or vehicle, i.e., make it 
unusable for its intended purpose; or
    (iii) Require more than 8 workhours to dismantle using appropriate 
equipment. The applicant for a nondivisible load permit has the burden 
of proof as to the number of workhours required to dismantle the load.
    (2) A State may treat as nondivisible loads or vehicles: emergency 
response vehicles, including those loaded with salt, sand, chemicals or 
a combination thereof, with or without a plow or blade attached in 
front, and being used for the purpose of spreading the material on 
highways that are or may become slick or icy; casks designed for the 
transport of spent nuclear materials; and military vehicles transporting 
marked military equipment or materiel.
    Over-the-road bus. The term over-the-road bus means a bus 
characterized by an elevated passenger deck located over a baggage 
compartment, and typically operating on the Interstate System or roads 
previously designated as making up the Federal-aid Primary System.
    Saddlemount combination. A saddlemount combination is a combination 
of vehicles in which a truck or truck tractor tows one or more trucks or 
truck tractors, each connected by a saddle to the frame or fifth wheel 
of the vehicle in front of it. The saddle is a mechanism that connects 
the front axle of the towed vehicle to the frame or fifth wheel of the 
vehicle in front and functions like a fifth wheel kingpin connection. 
When two vehicles are towed in this manner the combination is called a 
double saddlemount combination. When three vehicles are towed in this 
manner, the combination is called a triple saddlemount combination.
    Single axle weight. The total weight transmitted to the road by all 
wheels whose centers may be included between two parallel transverse 
vertical planes 40 inches apart, extending across the full width of the 
vehicle. The Federal single axle weight limit on the Interstate System 
is 20,000 pounds.
    Special mobile equipment. Every self-propelled vehicle not designed 
or used primarily for the transportation of persons or property and 
incidentally operated or moved over the highways, including military 
equipment, farm equipment, implements of husbandry, road construction or 
maintenance machinery, and emergency apparatus which includes fire and 
police emergency equipment. This list is partial and not exclusive of 
such other vehicles as may fall within the general terms of this 
definition.
    Stinger-steered combination. A truck tractor semitrailer wherein the 
fifth wheel is located on a drop frame located behind and below the 
rear-most axle of the power unit.

[[Page 280]]

    Tandem axle weight. The total weight transmitted to the road by two 
or more consecutive axles whose centers may be included between parallel 
transverse vertical planes spaced more than 40 inches and not more than 
96 inches apart, extending across the full width of the vehicle. The 
Federal tandem axle weight limit on the Interstate System is 34,000 
pounds.
    Terminal. The term terminal as used in this regulation means, at a 
minimum, any location where:
    Freight either originates, terminates, or is handled in the 
transportation process; or
    Commercial motor carriers maintain operating facilities.
    Tractor or Truck tractor. The noncargo carrying power unit that 
operates in combination with a semitrailer or trailer, except that a 
truck tractor and semitrailer engaged in the transportation of 
automobiles may transport motor vehicles on part of the power unit, and 
a truck tractor equipped with a dromedary unit operating in combination 
with a semitrailer transporting Class 1 explosives and/or any munitions 
related security material as specified by the U.S. Department of Defense 
in compliance with 49 CFR 177.835 may use the dromedary unit to carry a 
portion of the cargo.
    Truck-tractor semitrailer-semitrailer. In a truck-tractor 
semitrailer-semitrailer combination vehicle, the two trailing units are 
connected with a ``B-train'' assembly. The B-train assembly is a rigid 
frame extension attached to the rear frame of a first semitrailer which 
allows for a fifth wheel connection point for the second semitrailer. 
This combination has one less articulation point than the conventional 
``A dolly'' connected truck-tractor semitrailer-trailer combination.
    Truck-trailer boat transporter. A boat transporter combination 
consisting of a straight truck towing a trailer using typically a ball 
and socket connection. The trailer axle(s) is located substantially at 
the trailer center of gravity (rather than the rear of the trailer) but 
so as to maintain a downward force on the trailer tongue.
    Width exclusive devices. Devices excluded from the measurement of 
vehicle width. Such devices shall not be designed or used to carry 
cargo.

[49 FR 23315, June 5, 1984, as amended at 53 FR 2597, Jan. 29, 1988; 53 
FR 12148, Apr. 13, 1988; 53 FR 25485, July 7, 1988; 53 FR 48636, Dec. 2, 
1988; 55 FR 22762, June 1, 1990; 55 FR 32399, Aug. 9, 1990; 59 FR 30419, 
June 13, 1994; 63 FR 70652, Dec. 22, 1998; 64 FR 48959, Sept. 9, 1999; 
67 FR 15109, Mar. 29, 2002; 68 FR 37968, June 26, 2003; 69 FR 11996, 
Mar. 12, 2004; 72 FR 7747, Feb. 20, 2007]