Commercial Vehicle - Oversize/overweight permits - Top six questions

1.  Where do I find mileposts?
Mileposts are on the State Route Milepost Map . You will need a beginning and ending milepost for each state route that you are using with single trip oversize/overweight permits. There is a state wide map and a Puget Sound/Seattle Area map.

2.  Do I need pilot/escort vehicles?
A pilot/escort vehicle and operator must comply with the requirements of WAC 468-38-100 Escort vehicle requirements. Pilots/Escort vehicles are required when:

  1. Vehicle(s) or load is over 11 ft. in width; escort cars (both front and rear) are required on all two lane highways.
  2. Vehicle(s) or load is over 14 feet wide; one rear escort vehicle is required on multiple-lane highways.
  3. Trailer length including load exceeds 105 ft., of a tractor/trailer combination, requires a rear escort car on all two-lane highways.
  4. Trailer length including load exceeds 125 ft., of a tractor/trailer combination, requires a rear escort car on multiple-lane highways.
  5. Rear overhang of a tractor/trailer or truck/trailer combination exceeds 1/3 of the trailer length
    including load, requires one rear escort on two lane highways.
  6. Rear overhang exceeds 20 ft. of a single unit vehicle, requires one rear escort car on two-lane highways.
  7. Loads exceed 14 ft. and 6 inches high, one escort vehicle is required in front equipped with a height pole. Manufactured housing requires front escort with height pole when exceeding 15 ft. in height. The Department does not guarantee height clearances; therefore, on any route where the height is in question, a front escort vehicle equipped with a height pole should be used.
  8. In the opinion of the Department of Transportation, escort vehicles are necessary to protect the traveling public, for any over-dimensional and/or overweight move, either across, upon, or along a highway. 

3.  Can I buy my permit at a weigh station?
No, permits cannot be purchased at the weigh stations. You will need to have your permits prior to entering the state or before moving your load. Here is a list of permitting offices and agents .

4.  Can I buy my permit(s) online?
Yes, if you are a self issuer you can obtain most types of permits yourself. See Online Self Issue permits for more information.

5.  How do I determine my permitted and legal hauling capacity in Washington?
By obtaining an axle spacing report number by entering your vehicle combination information in the axle calculator . You will need the tire size of all two-tire axles and the distance between each axle (feet and inches). Once you have entered in the required information you can calculate and save to get your five-digit axle spacing report number. View our Help menu if you need assistance.

6.  How much are permits?

  • Trip (temporary license) permits are $25 (valid for 3 days)
  • Fuel (Temporary IFTA) permits are $30 (valid for 3 days)
  • Width and height permits are $20 per month
  • Length permits are $10 per month
  • Single trip oversize permits are $10 per trip
  • Weight permits are based on your gross weight over your legal weight. ( Special Permit - Fees )

See our Permit Types and Information for more details about specific permits.

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