Washington Trailer Brake Laws 2026: Required Over 3,000 lb
Washington requires brakes on all wheels except for trailers, cargo extensions, semitrailers, or pole trailers not exceeding 3,000 lb when wheel weight is no more than 40% of the towing vehicle gross weight and the combination meets performance standards.
Quick answer: 3,000 lb gross weight
In Washington, trailer brakes are currently listed at 3,000 lb (gross weight). Washington measures gross weight, so weigh the trailer as you actually tow it.
| Requirement | State rule | Applies when | Source | Last checked |
|---|---|---|---|---|
| Trailer brakes | 3,000 lb | gross weight | Verified | 2026-07-13 |
| Breakaway switch | Every trailer with air or vacuum actuated brakes, and every one over 3,000 lb gross weight manufactured or assembled after January 1 1964, must have brakes on all wheels that apply automatically and promptly and remain applied at least 15 minutes upon breakaway. | Trailer type and weight may matter | RCW 46.37.340(4) | 2026-07-13 |
| Safety chains | Every towed vehicle must be coupled by two safety chains, cables or wire ropes in addition to the drawbar or tongue. Attachments must be equidistant from the centerline, must not use the ball or its fasteners, and the chains must be crossed so the tongue cannot drop to the ground. | Conventional trailer couplings | WAC 204-70-070 | 2026-07-13 |
| Speed / lane rule | Towing-specific: the maximum speed for vehicles over 10,000 lb gross weight and for vehicles in combination â which includes anything towing a trailer â may not exceed 60 mph, and may be set lower by the secretary of transportation. | Posted roads and vehicle combinations | RCW 46.61.410(2), (3) | 2026-07-13 |
| Double towing | Needs verification with Washington RCW. | Multiple-trailer combinations | Verified | 2026-07-13 |
Official source links
Washington requires brakes on all wheels except for trailers, cargo extensions, semitrailers, or pole trailers not exceeding 3,000 lb when wheel weight is no more than 40% of the towing vehicle gross weight and the combination meets performance standards.
How the 3,000 lb threshold applies to three trailers
Washington measures gross weight, so the weight of the trailer as loaded is what counts.
| Example trailer | Weight checked | Against 3,000 lb |
|---|---|---|
| Small utility trailer | 1,650 lb | Under the Washington threshold by 1,350 lb |
| Loaded just under the line | 2,900 lb | Inside the Washington limit, but one heavy load away from crossing it |
| Mid-size travel trailer | 4,800 lb | Over the Washington threshold by 1,800 lb â brakes required |
Washington trailer equipment rules
Safety chains
RequiredEvery towed vehicle must be coupled by two safety chains, cables or wire ropes in addition to the drawbar or tongue. Attachments must be equidistant from the centerline, must not use the ball or its fasteners, and the chains must be crossed so the tongue cannot drop to the ground.
WAC 204-70-070 âBreakaway system
RequiredEvery trailer with air or vacuum actuated brakes, and every one over 3,000 lb gross weight manufactured or assembled after January 1 1964, must have brakes on all wheels that apply automatically and promptly and remain applied at least 15 minutes upon breakaway.
RCW 46.37.340(4) âSpeed limit when towing
Towing-specific: the maximum speed for vehicles over 10,000 lb gross weight and for vehicles in combination â which includes anything towing a trailer â may not exceed 60 mph, and may be set lower by the secretary of transportation.
RCW 46.61.410(2), (3) âRead against the linked sources on . Statutes change and enforcement varies by trailer type â confirm before you tow.
Towing more than one trailer in Washington
Needs verification with Washington RCW.
Speed and lane rules when towing in Washington
Needs verification; follow posted limits.
How Washington compares with neighbouring states
1 of the 2 states bordering Washington set a stricter brake threshold, so a trailer that is legal here may need brakes as soon as you cross the line. Equip for the strictest state on your route.
| Bordering state | Brake threshold | Compared with Washington |
|---|---|---|
| Idaho | 1,500 lb unladen weight | 1,500 lb stricter |
| Oregon | verified stopping-distance performance rule | Different rule type â compare directly |
Planning a multi-state trip? The route brake law checker compares every state on a route at once.
Related towing tools
Washington towing law FAQ
Are trailer brakes required in Washington?
Washington currently lists a trailer brake threshold at 3,000 lb gross weight. Always verify the official state source before towing.
What weight requires trailer brakes in Washington?
The current data lists 3,000 lb gross weight as the brake threshold.
Is a breakaway switch required in Washington?
Every trailer with air or vacuum actuated brakes, and every one over 3,000 lb gross weight manufactured or assembled after January 1 1964, must have brakes on all wheels that apply automatically and promptly and remain applied at least 15 minutes upon breakaway. (RCW 46.37.340(4))
Are safety chains required in Washington?
Every towed vehicle must be coupled by two safety chains, cables or wire ropes in addition to the drawbar or tongue. Attachments must be equidistant from the centerline, must not use the ball or its fasteners, and the chains must be crossed so the tongue cannot drop to the ground. (WAC 204-70-070)
Can I tow two trailers in Washington?
Needs verification with Washington RCW.
Is there a towing speed limit in Washington?
Towing-specific: the maximum speed for vehicles over 10,000 lb gross weight and for vehicles in combination â which includes anything towing a trailer â may not exceed 60 mph, and may be set lower by the secretary of transportation. (RCW 46.61.410(2), (3))
Does Washington measure trailer weight as GVWR or actual weight?
Washington uses gross weight, so weigh the trailer as you actually tow it rather than reading the data plate.
Where can I verify Washington towing laws?
Start with the 3 official sources linked on this page, beginning with RCW 46.37.340 braking equipment. Prefer state DOT, DMV, legislature, or public-safety pages over summaries from private websites. This page was last checked on 2026-07-13.