WAIS Document Retrieval[Code of Federal Regulations]

[Title 49, Volume 5, Parts 400 to 999]

[Revised as of October 1, 1999]

From the U.S. Government Printing Office via GPO Access

[CITE: 49CFR571.224]

[Page 644-647]

TITLE 49--TRANSPORTATION

CHAPTER V--NATIONAL HIGHWAY TRAFFIC

SAFETY ADMINISTRATION, DEPARTMENT

OF TRANSPORTATION

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents

Subpart B--Federal Motor Vehicle Safety Standards

Sec. 571.224 Standard No. 224; Rear impact protection.

S1. Scope. This standard establishes requirements for the

installation of rear impact guards on trailers and semitrailers with a

gross vehicle weight rating (GVWR) of 4,536 kg or more.

S2. Purpose. The purpose of this standard is to reduce the number of

deaths and serious injuries occurring when light duty vehicles impact

the rear of trailers and semitrailers with a GVWR of 4,536 kg or more.

S3. Application. This standard applies to trailers and semitrailers

with a GVWR of 4,536 kg or more. The standard does not apply to pole

trailers, pulpwood trailers, special purpose vehicles, wheels back

vehicles, or temporary living quarters as defined in 49 CFR 529.2. If a

cargo tank motor vehicle, as defined in 49 CFR 171.8, is certified to

carry hazardous materials and has a rear bumper or rear end protection

device conforming with 49 CFR part 178 located in the area of the

horizontal member of the rear underride guard required by this standard,

the guard need not comply with the energy absorption requirement

(S5.2.2) of 49 CFR 571.223.

S4. Definitions.

Chassis means the load supporting frame structure of a motor

vehicle.

Horizontal member means the structural member of the guard that

meets the configuration requirements of S5.1 of this section when the

guard is installed on the vehicle according to the

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installation instructions or procedures required by S5.5 of

Sec. 571.223, Rear Impact Guards.

Low chassis vehicle means a trailer or semitrailer having a chassis

that extends behind the rearmost point of the rearmost tires and a lower

rear surface that meets the configuration requirements of S5.1.1 through

5.1.3 of this section.

Outer or Outboard means away from the trailer centerline and toward

the side extremities of the trailer.

Pulpwood trailer means a trailer that is designed exclusively for

harvesting logs or pulpwood and constructed with a skeletal frame with

no means for attachment of a solid bed, body, or container.

Rear extremity means the rearmost point on a vehicle that is above a

horizontal plane located 560 mm above the ground and below a horizontal

plane located 1,900 mm above the ground when the vehicle is configured

as specified in S5.1 of this section and when the vehicle's cargo doors,

tailgate, or other permanent structures are positioned as they normally

are when the vehicle is in motion. Nonstructural protrusions such as

taillights, rubber bumpers, hinges and latches are excluded from the

determination of the rearmost point.

Rounded corner means a guard's outermost end that curves upward or

forward toward the front of the vehicle, or both.

Side extremity means the outermost point on a vehicle's side that is

located above a horizontal plane 560 mm above the ground, below a

horizontal plane located 190 cm above the ground, and between a

transverse vertical plane tangent to the rear extremity of the vehicle

and a transverse vertical plane located 305 mm forward of that plane

when the vehicle is configured as specified in S5.1 of this section.

Non-structural protrusions such as taillights, hinges, rubber bumpers,

and latches are excluded from the determination of the outermost point.

Special purpose vehicle means a trailer or semitrailer having work-

performing equipment that, while the vehicle is in transit, resides in

or moves through the area that could be occupied by the horizontal

member of the rear underride guard, as defined by S5.1.1 through S5.1.3.

Wheels back vehicle means a trailer or semitrailer whose rearmost

axle is permanently fixed and is located such that the rearmost surface

of tires of the size recommended by the vehicle manufacturer for the

vehicle on that axle is not more than 305 mm forward of the transverse

vertical plane tangent to the rear extremity of the vehicle.

S5. Requirements.

S5.1 Installation; vehicle configuration. Each vehicle shall be

equipped with a rear impact guard certified as meeting Federal Motor

Vehicle Safety Standard No. 223, Rear Impact Guards (Sec. 571.223). When

the vehicle to which the guard is attached is resting on level ground,

unloaded, with its full capacity of fuel, and with its tires inflated

and air suspension, if so equipped, pressurized in accordance with the

manufacturer's recommendations, the guard shall comply with the

requirements of S5.1.1 through S5.1.3 of this section. See Figure 1 of

this section.

S5.1.1 Guard width. The outermost surfaces of the horizontal member

of the guard shall extend outboard to within 100 mm of the longitudinal

vertical planes that are tangent to the side extremities of the vehicle,

but shall not extend outboard of those planes. See Figure 1 of this

section.

S5.1.2 Guard height. The vertical distance between the bottom edge

of the horizontal member of the guard and the ground shall not exceed

560 mm at any point across the full width of the member. Notwithstanding

this requirement, guards with rounded corners may curve upward within

255 mm of the longitudinal vertical planes that are tangent to the side

extremities of the vehicle. See Figure 1 of this section.

S5.1.3 Guard rear surface. At any height 560 mm or more above the

ground, the rearmost surface of the horizontal member of the guard shall

be located as close as practical to a transverse vertical plane tangent

to the rear extremity of the vehicle, but no more than 305 mm forward of

that plane. Notwithstanding this requirement, the horizontal member may

extend rearward of the plane, and guards

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with rounded corners may curve forward within 255 mm of the longitudinal

vertical planes that are tangent to the side extremities of the vehicle.

S5.2 Installation Requirements. Guards shall be attached to the

vehicle's chassis by the vehicle manufacturer in accordance with the

installation instructions or procedures provided pursuant to S5.5 of

Standard No. 223, Rear Impact Guards (Sec. 571.223). The vehicle must be

of a type identified in the installation instructions as appropriate for

the guard.

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[61 FR 2035, Jan. 24, 1996, as amended at 63 FR 3662, Jan. 26, 1998]