New Federal Rule Would require Maintenance of Rear Underride Guards

THE Federal Highway Administration (FHWA) issued a notice of proposed rulemaking (NPRM) on May 14, 1998, for the parts and accessories necessary for the safe operation of rear impact guards and rear impact protection.

If adopted, this rule require motor carriers to maintain the underride protection devices on certain trailers and semitrailers manufactured on or after January 26, 1998.

Without this amendment to the federal motor carrier safety regulations, no federal requirement would exist for motor carriers to maintain trailers to comply with rear impact protection requirements or repair damaged rear impact guards. Motor carriers also could replace rear impact guards with devices that fail to comply with requirements of the National Highway Traffic Safety Administration (NHTSA).

The FHWA proposal may include detailed requirements to help motor carriers determine if an underride device on a newly manufactured trailer meets the NHTSA's requirements. Requiring rear impact guards on foreign-based trailers operated in the US is appropriate, the FHWA said in its proposal. The FHWA is requesting comments from Canada- and Mexico-based motor carriers and original equipment manufacturers that sell trailers and semitrailers for the Canadian and Mexican markets.

The new rule would require trailers operated in interstate commerce and manufactured on or after January 26, 1998, to comply with Federal Motor Vehicle Safety Standard (FMVSS) 223 and 224. Rear impact guards would be required on trailers manufactured after December 31, 1952, in which the vertical distance between the rear bottom edge of the body or chassis assembly and the ground is greater than 30 inches (76.2 centimeters) when the motor vehicle is empty.

Currently, FMVSS 223 and 224 are applicable only to vehicle and vehicle component manufacturers.

FMVSS 223 specifies performance requirements that rear impact guards must meet before they can be installed on new trailers and semitrailers. This safety standard specifies strength requirements for impact guards and test procedures that manufacturers and the NHTSA will use to determine compliance with the standard. FMVSS 223 requires guard manufacturers to permanently label the impact guard to certify it meets requirements and to provide instructions on correct installation.

FMVSS 224 requires that most new trailers and semitrailers with a gross vehicle weight rating (GVWR) of 10,000 lb (4,536 kilograms) or more be equipped with a rear impact guard meeting requirements of FMVSS 223. FMVSS 224 also specifies that the location of the guard and its mounting on the trailer must follow the instructions of the guard manufacturer.

Trailers affected by this proposed rule must meet other requirements in the amendment for: *Impact guard width. The outermost surfaces of the impact guard's horizontal member must extend to within four inches (100 millimeters) of the side extremities of the vehicle. The outermost surface of the horizontal member shall not extend beyond the side extremity of the vehicle.

*Guard height. The vertical distance between the bottom edge of the horizontal member of the guard and the ground shall not exceed 22 inches (560 millimeters) at any point across the full width of the member. Guards with rounded corners may curve upward within 10 inches (255 millimeters) of the longitudinal vertical planes that are tangent to the side extremities of the vehicle.

*Guard rear surface. At any height more than 22 inches (560 millimeters) above the ground, the rearmost surface of the horizontal member of the guard must be within 12 inches (305 millimeters) of the rear extremity of the vehicle. But the rear surface of the guard may extend beyond the rear of the vehicle. Guards with rounded corners may curve forward within 10 inches (254 millimeters) of the side extremity.

*Cross-sectional vertical height. The horizontal member of each guard must have a cross-sectional vertical height of at least 3.94 inches (100 millimeters) at any point across the guard width.

*Certification and labeling requirements for rear-impact protection guards. Each rear-impact guard must be permanently marked or labeled as required by FMVSS 223. The label must be on the forward-facing surface of the horizontal member of the guard, 12 inches (305 millimeters) inboard of the right end of the guard.

The certification label must contain the name and address of the manufacturer of the impact guard, the date the guard was manufactured, and the letters "DOT," which mean the guard conforms to FMVSS 223.

None of the requirements apply to pole trailers, pulpwood trailers, low-chassis trailers, special purpose trailers, wheels-back trailers, and trailers towed in driveaway-towaway operations.

*A low-chassis trailer has a chassis that extends behind the rearmost point of the rearmost tires and a lower rear surface that meets the guard width, height, and rear surface requirements.

*A pulpwood trailer is designed exclusively for hauling logs or pulpwood. It is constructed with a skeletal frame that has no means for attachment for a solid bed, truck body, or container.

*A rear extremity is the rearmost point on a trailer that falls above a horizontal plane 22 inches (560 millimeters) above the ground and below a horizontal plane 75 inches (1,900 millimeters) above the ground. These measurements are made when the trailer is stopped on level ground, unloaded with full fuel tanks, tires and any air suspension inflated. The cargo doors, tailgate, and other equipment are positioned for an in-motion vehicle. Nonstructural protrusions such as taillamps, rubber bumpers, hinges, and latches are excluded from the determination of the rearmost point.

*A side extremity is the outermost point on the side of a trailer that is above a horizontal plane 22 inches (560 millimeters) above the ground, below a horizontal plane 75 inches (1,900 millimeters) above the ground, and between a transverse vertical plane tangent to the rear extremity of the vehicle and a transverse vertical plane located 12 inches (305 millimeters) forward of that plane when the vehicle is unloaded with full fuel tanks and the tires and any air suspension inflated. Nonstructural protrusions such as taillamps, hinges, and latches are excluded from the determination of the outermost point.

*A special purpose vehicle is a trailer having working 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 impact guard.

*A wheels-back trailer is one whose rearmost axle is permanently fixed and is located such that the rearmost surface of the tires is not more than 12 inches (305 millimeters) forward of the transverse vertical plane tangent to the rear extremity of the vehicle.

The FHWA is not proposing a retrofitting requirement for improved rear impact protection on trailers manufactured before January 26, 1998.

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