Washington transportation regulations

The legal weight, dimension and axle limits for commercial vehicles in Washington, and where the state permit office is.

Your route

Washington is highlighted. Select the other states on your route to compare their limits.

Legal dimensions

MeasureLegal maximum
Width8' 6"
Height14'
Length, semi-trailer53'
Length, single vehicle40'
Length, overall75'
Front overhang3'
Rear overhang15'

Legal weights

MeasureLegal maximum
Gross vehicle weight80,000 lbs
Gross weight, single vehicle
Single axle20,000 lbs
Tandem axle34,000 lbs
Tridem axle
Single axle, non-divisible
Tandem axle, non-divisible
Tridem axle, non-divisible

Last checked September 2026. States revise legal limits, and a limit can depend on the road, the axle spacing or the configuration in ways one table cannot capture. Washington is the authority — use this to plan, and confirm anything you are close to.

Washington permit offices

Oversize/ Overweight / Temporary Trip/ Fuel

Oversize / Overweight

Phone
(360) 704-6340
Fax
(360) 704-6391
Email
CVSpermits@wsdot.wa.gov