Washington Trailer Towing Laws

The Washington State Patrol determines and enforces laws for trailer towing in Seattle and throughout Washington and puts specific requirements in place for homemade trailers. These rules help to increase safety and prevent accidents. They also help to minimize delays during transit due to malfunctioning equipment. Washington’s rules regulate trailer dimensions, weight, hitch features, safety chains, and licensing. By carefully familiarizing yourself with the rules for towing a trailer you not only avoid fines and potential impoundment but also accidents in which you could be held liable.

Understanding Size Limits for Trailers in Washington

The allowable length and width measurements of trailers help to ensure safe travel and correspond with the average width of roads and freeway lanes within the state. Washington State Patrol allows trailers of up to 53 feet in length. In some circumstances, trailers can be up to 56 feet long with a special permit. A truck and trailer together cannot exceed a total length of 75 feet. Trailers can be up to 8 feet, 6 inches in width. Trailers with their loads in place cannot exceed heights of 14 feet.

How Heavy Can a Trailer Be in Washington?

Washington State regulations allow load weights of up to 20,000 pounds for trailers pulled by single-axel vehicles such as pickup trucks and SUVs. Dual-axel vehicles may pull trailers of up to 34,000 pounds. Because tire size is important in safely towing trailers, the weight limit for loads corresponds to tire size. The state’s regulations allow 600 pounds of weight per inch of tire width.

Understanding Trailer Hitch Regulations

Trailer hitch ball regulations depend on what type of trailer a vehicle is towing. Class types coincide with the weight of the trailer. The regulations for trailer hitches are as follows:

• Class 1 trailers are those with a gross weight of less than 1 ton and require a hitch ball of at least 1 ⅞ inches in diameter. They must be able to withstand at least 3 tons of longitudinal tension and 1.5 tons of vertical tension.
• Class 2 trailers of 1 to 1.75 tons require a hitch ball with at least a 2-inch diameter and must withstand up to 5.5 tons of longitudinal tension and a vertical tension of 2.5 tons.
• Class 3 trailers weighing between 1.75 and 2.5 tons must use a hitch ball of at least 2 inches and have a rating to haul up to 7.5 tons longitudinal and 3.5 tons vertical tension.

What are Washington’s Safety Chain Requirements?

Washington State Patrol also regulates safety chain requirements for chains extending from the trailer neck to the hitch on a vehicle. For pulling a class 1 trailer, the safety chain must have a 2-ton rating. Class 2 trailers require a 1.75-ton rating, and class 3 trailers require a chain with a 2.5-ton rating. The rating requirements are the same for hook and eye attachments.

Rules and Guidelines to Keep in Mind While Towing a Trailer

• Trailers require turn signals, brake lights, license plate lights, and reflectors
• Drawbar connections must be sufficiently strong to prevent trailer whipping, weaving, or failing
• Side mirrors on both left and right sides must reflect up to 200 feet and may extend up to 5 inches
• Towing drivers must follow the posted speed limits for trucks
• Towing drivers must avoid the left lane of any 3-lane one-directional roadway unless making a left turn
• No passengers can ride in a towed trailer unless it’s steerable and includes a proper seating position
• Trailers must include brakes rated for their maximum weights

When towing a trailer, drivers must understand they have a duty of care to prevent accidents by taking extra precautions, adjusting their driving appropriately to compensate for the extended length, and carefully monitoring speed so as not to present a hazard to other drivers on the road. If you or a loved one was injured in an accident involving a car that was towing a trailer, contact a Seattle car accident lawyer to explore your legal options. You may be able to recover financial compensation.