Idaho Trailer Laws & Trailer Regulations

Idaho's laws and regulations for trailers are listed below:


Idaho Trailer Brake Laws

Trailers with an unloaded weight of 1,500 lbs. must have an independent braking system, and a breakaway system capable of applying the brakes in the event of a separation from the towing vehicle is required. 



Idaho Trailer Dimension Laws

Total length: 75 feet; trailer length: 48 feet (both total and trailer length limits include bumpers but exclude devices or appurtenances related to safe or efficient operation of the vehicle); width: 102 inches (the width excludes devices or appurtenances related to safe or efficient operation of the vehicle; clearance lights, door handles, window fasteners, handholds, door and window trim, molding and load securement devices, may extend up to 3″ on each side of vehicle.); height: 14 feet. 



Idaho Trailer Hitch and Signal Laws

Hitch must be secured to frame; no safety chain required. 



Idaho Trailer Lighting Laws

Every trailer, semitrailer, pole trailer, or any other drawn vehicle at the end of a train of vehicles must have 1 rear tail lamp, which when lit will emit a red light plainly visible from a distance of 500 feet to the rear.

Every trailer, semitrailer, or pole trailer weighing 3,000 lbs. gross or less must have 2 reflectors on the rear, 1 on each side, and 2 reflectors on the front, 1 on each side.

Any trailer that blocks the stoplight of the towing vehicle, whether loaded or unloaded, must also have 1 stoplight.



Idaho Trailer Mirror Laws

Left- and right-side mirrors are required if a Driver’s view straight to the rear is obstructed. 



Idaho Trailer Speed Limit Laws

Same as passenger cars. 



Idaho Trailer Towing Laws

Passenger or pleasure vehicles may tow 2 units behind them.  






The United States Trailer Laws and Regulations by State by is not an inclusive list of laws, regulations and it should be used by reference only and not used for any other purpose. is not liable for incorrect or incomplete information. To report an error, incomplete or incorrect information, please send an email to