Overview
Washington State oversize and overweight permits are issued by the Washington State Department of Transportation. Single-trip permits involving weight are usually valid for one move; overdimensional-only permits may be issued for a month or a year.
Permit approval depends on the proposed route, dimensions, axle weights and overhead/corner clearances.
Permit Office
| Office | Washington State Department of Transportation |
| Address | 4582 Woodview Drive Southeast, Lacey, Washington 98503 |
| Contact | (360) 704-6340 / 1 (800) 562-6902 |
| Hours | 7:00 A.M. – 5:00 P.M. (PT) |
Permit Basics
| Operating time | 7:00 A.M. – 5:00 P.M. (PT) |
Dimensions & Weights
Routine permit limits
| Length | No overall length set; permit allows movement on routes the permittee can negotiate |
| Width | 14′ or less on 2-lane highways; 32′ or less on multi-lane undivided highways; 20′ if opposing lanes separated by a physical barrier. Must be applied for in writing if over 16′. |
| Height | Over 16′ high requires written application demonstrating necessity and public interest. All loads over 14′ are governed by overhead-clearance obstacles. |
| Axle / group | Spacing | Weight |
|---|---|---|
| Single | — | 22,000 |
| Tandem | — | 43,000 |
| Tridum | — | 65,000 |
| Quad | — | 70,000 |
| Trunnion | — | 43,000 |
Escort Requirements
| Based on | Escorts required |
|---|---|
| Width | On 2-lane highways — width over 11′: 2 (front & rear) |
| Width | On multiple-lane highways — width over 14′–20′: 1 rear |
| Width | On multiple-lane highways — width over 20′: 2 (front & rear) |
| Length | On 2-lane highways — length over 105′: 1 rear |
| Length | On multiple-lane highways — length over 125′: 1 rear |
| Overhang | On 2-lane highways — front overhang (depends on routes): 1 front |
| Overhang | On 2-lane highways — rear overhang when load measured from center of last axle exceeds ⅓ of total length: 1 rear |
| Overhang | On multiple-lane highways — front overhang over 20′ measured from steering axle on 2-lane roads: 1 front |
| Height | On 2-lane highways — height over 14′6″ (city/county authorizations necessary for detours): 1 front with height pole |
| Height | On multiple-lane highways — height over 14′6″: 1 front with height pole |
Notes
- Gross Weight — 5 Axles: 99,200 (variable depending on bridge formula)
- Gross Weight — 6 Axles: 108,000 (variable depending on bridge formula)
- Gross Weight — 7 Axles: 134,000 (variable depending on bridge formula)
- Gross Weight — 8 Axles: 156,000 (variable depending on bridge formula)