DOT Regulations for Pull Behind Trailers

by Amy Yang
itstillruns article image
remorque image by Nath Photos from

Pull behind trailers are subject to the standards set forth by the National Highway Traffic Safety Administration. Title 49 of the United States Code mandates this administration and auto manufacturers must meet the standards set forth by that administration. All the standards are written to protect the public from unreasonable risk.

Rear Impact Guards

According to Standard Numbers 223 and 224 issued by the National Highway Traffic Safety Administration, trailers are required to have rear impact guards installed if the trailer's gross weight is 10,000 pounds or more.The purpose of this regulation is to lower the number of injuries and deaths associated with the collision of smaller vehicles to the larger trailer.


Standard Number 108 requires trailers to have functioning original or replacement lights. This standard applies to the lamps, reflective devices and any other devices associated with the lighting system. Pull behind trailers must have working rear lights, turn lights and brake lights. A properly functioning light system increases visibility and enables other drivers to see turn, brake and emergency signals. Its purpose is also to reduce injuries and death from collisions. Proper lighting is essential at night and during times of limited visibility. Lights during the daytime make it easier for other drivers to spot the trailer.


Standard Numbers 119 and 120 state that appropriate tire selection is required. The tires must be of sufficient size and have the appropriate load rating. The rims must be of a particular size, type and identification. The exact type depends on the type of pull behind trailer. The purpose for these two standards is to ensure that tires are chosen properly for the safe operation of the trailer.

More Articles

article divider