Verified
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.
- Brake threshold
- 3,000lbgross weight
- Breakaway switch
- Required
- Safety chains
- Required
- Towing speed
- Special limit
- Double towing
- Not recorded
On this page8 sections
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.
Washington trailer equipment rules
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.
- Applies when
- Trailer type and weight may matter
- Source
- RCW 46.37.340(4)
- Last checked
- 2026-08-21
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.
- Applies when
- Conventional trailer couplings
- Source
- WAC 204-70-070
- Last checked
- 2026-08-21
Speed / lane rule
Towing-specific: the maximum speed for vehicles over 10,000 lb gross weight and for vehicles in combination — which includes anything towing a trailer — may not exceed 60 mph, and may be set lower by the secretary of transportation.
- Applies when
- Posted roads and vehicle combinations
- Source
- RCW 46.61.410(2), (3)
- Last checked
- 2026-08-21
Double towing
Needs verification with Washington RCW.
- Applies when
- Multiple-trailer combinations
- Source
- Verified
- Last checked
- 2026-07-13
Read against the linked sources on . Statutes change and enforcement varies by trailer type — confirm before you tow.
Check your setup
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 — brakes required |
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 — compare directly |
Planning a multi-state trip? The route brake law checker compares every state on a route at once.
Official source links
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 — which includes anything towing a trailer — 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.
Disclaimer: educational summary, not legal advice. Statutes and enforcement practice change — verify the Washington sources linked above before towing.