Preserving our roads & bridges

Learn how we maintain our state's highway system to keep people safe and goods moving 24-hours-a-day, 365-days-a-year.

We oversee the day-to-day needs of maintaining our state's highway system, including:

  • 20,679 highway lane miles (includes ramps, collectors and special use lanes).
  • More than 3,000 bridges.
  • 1,100 traffic signal systems.
  • 10 major mountain passes kept open all year.
  • Close to 50 safety rest areas.

Bridge & structure preservation

Learn how we preserve, inspect and rate the condition of Washington state bridges.

Chip seal

Learn about chip seals (or seal coating, BST, Bituminous Surface Treatment), the application of a special protective wearing surface to an existing pavement.

Performance highlights from the Gray Notebook

14 fish passage projects were completed in 2020

improving access to 54.2 miles of upstream habitat.

11,959 incidents responded to

by WSDOT’s incident Response teams during second quarter of 2021, 15% more than same quarter in 2020.

41 Pre-existing Funds Projects Advertised

during the eighth quarter of the 2019-2021 biennium.