Bill Dawson Trail in Seattle closes for construction until 2030 beginning May 12

SEATTLE – People who walk, bike or roll through Seattle’s Montlake neighborhood will need to prepare for a five-year closure of the Bill Dawson Trail beginning Monday, May 12.

The trail will close as part of the SR 520 Portage Bay Bridge and Roanoke Lid Project. Contractor crews working for the Washington State Department of Transportation will use the closure to build a temporary haul road so crews and equipment can access the work trestle to build the new Portage Bay bridges.

What this means for you

People who regularly use this trail will need to follow the signed detours or use alternate routes. The trail will remain closed around-the-clock until 2030.

There will be two signed detour routes posted in and around the Montlake neighborhood – one for people walking/rolling, and the other for people biking. Montlake Playfield still will be accessible during the closure.

Learn more about the why

Read this online FAQ for detailed information on the trail closure and why it will remain for five years.

Bill Dawson Trail improvements

After the Portage Bay Project is complete, the trail between the west end of the new tunnel and the Montlake Playfield will be wider (from 8 feet to 14 feet) and flatter (grade no steeper than 5%). The connection from the Bill Dawson Trail to Montlake Boulevard near the NOAA property will be restored by adding new stairs and an ADA-compliant ramp on the west side of Montlake Boulevard.

In addition to the above improvements, the re-opened trail will have:

• A raised 6-foot-wide sidewalk – next to the 14-foot path – to separate walkers and bikers as they travel between the existing Montlake tunnel and the south side of the Portage Bay Bridge
• New lighting and more clearance under SR 520
• New landscaping and hardscaping (e.g., gravel, retaining walls, railings, etc.) features
• A new ramp structure connecting the Bill Dawson Trail to the new SR 520 Trail extension across Portage Bay

Stay up to date

To get the most up-to-date information on closures and construction work, visit and bookmark the SR 520 Construction Corner website. Real-time traffic maps are available on the WSDOT Travel Map. Be sure to follow us on social media both on Twitter/X and BlueSky for the latest updates.

People also may call or text our 24-hour construction hotline at 206-319-4520 or email us at sr520bridge@wsdot.wa.gov