2021 Washington state DOT

oversize and heavy-haul trucking laws, regulations, rules, limitations.

Washington state DOT rules and regulations for oversize and overweight trucking.

The great state of Washington official seal.

Please share your knowledge of Washington state shipping regulations with other visitors at the bottom of this page.

Washington trucking company and pilot car directory:

Washington State trucking company directory.
Washington State pilot cars and truck escorts.
Washington heavy-haul and oversize trucking permits.

Legal load limits.

Washington DOT legal load size & weight limitations: 

Length: The maximum overall length allowed legally is 75′.
Width: 8’ 6” wide.
Height: 14’ tall.
Weight: 80,000 lbs.
Overhang: 3′ in the front measured from the manufacturers front bumper and 15′ rear is the maximum and measured from the center of the rear axle.

Routine trucking permits.

Routine heavy haul, oversize shipping, trucking and transport permits:

Length: No set limits other than travel times. Case by case basis for routine maximums.
Width: 2 lane, 14′ or less, multi-lane roads with barrier strip 16′
Height:  16′ (note anything over 14′ will be required a pilot car w/height pole).
Weight: Single axle 22,000 lbs, tandem 34,000 lbs, tridum 55,000 lbs, quadem 70,000 lbs, gross weight on 5 axles 99,200 lbs, 6 axles 108,200 lbs, 8 axles 156,000 lbs.  These weights are limitations and totally dependent upon federal bridge formula.  Superload is 200,000 lbs. Also tire weight on all axles – 600 pounds per inch tire width.
Overhang: 3′ in the front and 15′ in the rear – also read in “legal loads” above.

NOTE: Non-divisible loads can not be made smaller or lighter. Exception: Dozers have have blade detached and sitting on trailer. No multiple blades. Loaders may have bucket detached as long as it is a pertinent piece for the loader being transported. No multiple buckets allowed.

Superload information.

Information on superloads for the state of Washington:

Superloads are classified as vehicles or loads that are non-divisible (or a combination of the two) that weigh in excess of 200,000 lbs or over 16′ in height or over 16′ in width in Washington state. A superload application must be submitted 30 days prior if your shipment exceeds the weight maximum or 7 days if exceeding the height or width maximums. You will need to document why it is in the best interest of the people of Washington state to grant you permission to perform the move, show that it can not be reduced in any way reasonable, have a mechanical drawing of the truck, trailer and shipment showing all of the axle positions, why you can’t perform the shipment via water, have an iron clad route in mind, a detailed plan for controlling traffic, how you plan to use your pilot cars, show that you are aware of all railroad route time tables if performing any crossings, and have a way to prove that any kind of emergency vehicle at any time can easily get past you. If you have all of this together then the Washington DOT will take a look at it and may even charge you for their time. Superloads in Washington should be completely handled by a professional or you may loose time and money. If you need assistance please see our consultation section as we have staff that specialize in superload shipments.

Legal truck travel times.

Travel times and restrictions in Washington:

7 days a week.  One half hour before sunrise and one half hour after sunset is permitted.  No movement after 3 pm on Fridays, Sunday and only travel until 12 noon.  Holiday travel is not permitted on the following holidays: New Years day, Memorial day, Labor day, Thanksgiving, Independence day and Christmas day.   If the holiday is on a Saturday or a Sunday there will be no Friday or Monday travel permitted.  The Washington State permit office is closed on the above holidays in addition to Martin Luther Kings day, Presidents day and Veterans day however travel is not restricted on these holidays as well as Columbus day and George Washington’s birthday.  Night travel is permitted for shipments that are under 12′ wide, 14′ 6″ in height and 105′ overall in length.  Overweight only loads that do NOT exceed any of the legal maximums in width, height or length are permitted to travel 24/7 as long as the tractor can maintain the minimum rated speed limit for that particular road or highway.

Notes:  There are travel restriction times during heavy traffic hours for Seattle, Tacoma, Spokane, Everett and Vancouver.  Please call the main number above for exact times or refer to the documentation on the permit that is issued.

When are pilot cars required.

Pilot car and escort vehicle information:

Length: If load is over 105′ in length you will be required to have 1 rear pilot car (escort).
Width: If over 11′ in width you will be required to have 1 front and 1 rear pilot car (escort).
Height: If height of load exceeds 14′ 6″ a front high pole pilot car (escort vehicle) is required.
Weight: If this is your only exceeded limit NO pilot car/escort vehicle is required as long as tractor can maintain minimum road speeds.
Overhang: No set limits, case by case basis.

Required pilot car and escort vehicle certifications.

Pilot car and escort vehicle certification and equipment requirements:

Pilot car or escort vehicles may be a car, truck of SUV as long as it has a gross vehicle maximum rating at least 14,000 pounds and a wheelbase of at least 60″ in width.  Headlights must be on at all times while escorting shipment. Each vehicle must be equipped with 2 amber lights on top of the vehicle and horizontally mounted rotating (or strobe) amber colored flashing light which must be visible from a 360 degree angle from a minimum of 500 feet.  Company identification signs must be placed on both sides of the pilot car (escort vehicle) displaying the name of the company, phone number and be placed on both the left and right hand sides of the vehicle. These signs must be no less that 8″ tall x 12″ wide and identity writing must be plainly legible. Vehicles must be equipped with a CB radio or 2-way communication device, a 5 pound fire extinguishers type A, B and C.  A sign hand help sign with the word “STOP” on one side and “SLOW” on the other with dimensions of no less than 18″ in diameter with a minimum of 6″ letters. 3 bi-directional road safety triangles.  While operating the vehicle the driver will is required to wear a reflective safety vest, jacket or shirt.  A orange hard hard and a first aid kit must be kept in the vehicle.  A non-conductive height measuring device that is to be used while escorting loads with any height in excess of 14′ 6″ and should be set at a length of no more than 6″ above the actual height of the load and no less than 3″.  Pilot car (escort vehicle) operators are NOT allowed to carry passengers other than co-workers. Washington state escort drivers are required by law to be state certified and have a copy of their Washington State Certification ID in the vehicle at all times.  Some programs in other states may qualify the driver to operate in Washington State but you will want to verify this by calling the main office number above.    Pilot cars (escort vehicles) must keep a distance of no less than 1/2 mile from the shipment they are escorting.  If at any time ANY vehicle either the actual shipment or escorting vehicle is delayed from each other said vehicle MUST pull over and wait for the other to resume position.  All pilot cars/escort vehicles must display a roof mounted “OVERSIZE LOAD” sign visible from both the front and rear of the vehicle.  Sign must be at least 5′ long and 12″ in height, yellow in color with black letters no less than 10″ tall and 1 1/2″ in width.  Sign must be a minimum of 5′ above the pavement.  Vehicle should  have 2 safety flags red or orange in color and be a minimum of 18″ of length and/or height mounted at a 40 to 70 degree angle on all 4 corners of the vehicle but this (the flags) are NOT mandatory at the time of this publishing.

Very heavy load being shipped.

Washington DOT information.

Contact information for Washington state DOT office:

Physical address:
State Department of Transportation
921 Lakeridge Way
PO Box 47367
Olympia, WA  98504-6340

Ports of entry:
The ports do NOT issue permits in the State of Washington.
Bow Hill: (I-5 S) 360-766-6196, Plymouth: (I-82 N) 509-734-7043, Ridgefield: (I-5 N) 360-887-8231, Spokane: (I-90 W) 509-226-3366

Email: if you know of a good one please leave it below.
Help telephone line: 360-704-6340
Fax: 360-704-6350
Hours: Monday – Friday 7:00 am – 5:o0 pm
Pacific Time Zone

Click here for the State DOT Website for oversize and over-weight hauling permits.
Click here for Washington State road & highway conditions.

Washington cities serviced.

The information contained in these pages is research information primarily for use by oversize and overweight trucking company drivers, dispatchers and pilot car companies. While every effort is put into maintaining the accuracy of this information you must absolutely verify this information with the Washington State DOT Permits office before commencing movement.


  1. As of June 3, 2017; Oversize loads requiring a high pole lead and are over 12′ wide, a rear pilot is also required on all multiple lane roadways. A signed copy of a single-trip permit is also required to be in the pilot car operators possession either hardcopy or electronic.

  2. 105. In length rear pilot. Add in that on 4 lane 125′ you need a pilot

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