Department of Transportation
WSDOT
Washington • United States of America
The Washington State Department of Transportation (WSDOT) manages over 7,000 centerline miles of state highways serving the nation's gateway to Pacific Rim trade. Key freight corridors include I-5, I-90, I-82, US-2, and SR-14. The Ports of Seattle and Tacoma, together forming the nation's fourth largest port complex, drive massive container freight movements that WSDOT's highway network must accommodate. The department administers commercial vehicle permits, manages critical mountain pass conditions on I-90 (Snoqualmie Pass) and US-2 (Stevens Pass), and operates the WSDOT app and 511WA for real-time freight-relevant road information. WSDOT also manages the largest state-owned ferry system in the US.
| Official Website | https://wsdot.wa.gov/ |
|---|---|
| Data API | https://wsdot.wa.gov/traffic/api/ |
| Founded | 1905 |
| Headquarters | Seattle |
Available Data
Social Media
- @wsdot — Washington State DOT
Washington Trucking Regulations
Size & weight limits, OS/OW permits, and seasonal restrictions for commercial vehicles
Weight Limits
| Category | Limit |
|---|---|
| Max Gross Vehicle Weight | 105500 lbs |
| Single Axle | 20000 lbs |
| Tandem Axle | 34000 lbs |
Dimensional Limits
| Category | Limit |
|---|---|
| Max Height | 14 ft |
| Max Width | 8.5 ft |
| Max Length (Single Unit) | 40 ft |
| Max Length (Combination) | 65 ft |
OS/OW Permits
Seasonal Restrictions Nov, Dec, Jan, Feb, Mar, Apr
Chain controls are enforced on mountain passes from approximately November through April. Snoqualmie Pass (I-90) and Stevens Pass (US-2) are the most heavily affected routes for commercial vehicles. Spring weight restrictions apply on some state and county roads, typically February through April.
Weigh Station Bypass
49¢/gal
Member
Special Exemptions
Notable Rules
Washington allows GVW up to 105,500 lbs on WSDOT-designated routes — significantly higher than the federal Interstate standard. Permits are required for loads exceeding standard Interstate limits. The Ports of Seattle and Tacoma are among the largest container ports in the US, generating heavy container haul traffic on I-5, I-405, and SR-509. Washington has one of the highest diesel fuel tax rates in the country.
Sources
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