Washington Trailer Laws & Trailer Regulations

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

Washington Trailer Brake Laws

Every trailer and pole trailer, and every vehicle combination must be equipped with service brakes adequate to control the movement of and to stop and hold the vehicle under all conditions of loading, and on any grade incident to its operation. Every trailer and pole trailer must be equipped with brakes acting on wheels except for those not exceeding a Gross Weight (GW) of 3,000 lbs. if the total weight on and including the wheels of the trailer or trailers does not exceed 40% of the GW of the towing vehicle when connected to the trailer. 

Washington Trailer Dimension Laws

Total length: 75 feet; trailer length: 53 feet; width: 8 1/2 feet; height: 14 feet.

Permits rearview mirror to extend 5 inches and safety appurtenances and appliances such as clearance lights, door latches, door hinges, and turn signal brackets to extend 4 inches and an awning to extend 6 inches.

Washington Trailer Hitch and Signal Laws

A vehicle towing a trailer must use safety chains.

The drawbar or other connection between vehicles in combination must be of sufficient strength to hold the weight of the towed vehicle on any grade where operated. No trailer may whip, weave, or oscillate or fail to follow substantially in the course of the towing vehicle.

Turn signals and reflectors are required.

Washington Trailer Lighting Laws

Tail, brake, and license plate lights are required.

Washington Trailer Mirror Laws

Every motor vehicle must be equipped with mirrors mounted on the left and right side of the vehicle and so located to reflect to the driver a view of the highway for a distance of at least 200 feet to the rear of such vehicle. 

Washington Trailer Speed Limit Laws

Same as posted for trucks.

Washington Trailer Towing Laws

No person may occupy any trailer while it is being moved on a public highway, except a person occupying a proper position for steering a trailer to be steered from a rear-end position.

No vehicle towing a trailer may be driven in the left-hand lane of a limited access roadway having 3 or more lanes for traffic moving in 1 direction except when preparing for a left turn.