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

Zero emission electric vehicle registrations in Washington

increased 192% between 2017 and 2021.

45 projects to improve freight rail structures and freight movement

were underway as of December 31, 2021.

Washington state leveraged $100,000 to secure $27 million

in funding for airport investments in Fiscal Year 2022.