SR 99 tunnel to close in both directions in Seattle for maintenance starting June 6

The State Route 99 tunnel in Seattle will close for maintenance from 10 p. m. on June 6 to 6 a. m. on June 7, impacting both northbound and southbound traffic.

The Washington State Department of Transportation will start closing lanes at 8:30 p. m. , with full closure by 10 p. m. Drivers traveling south must exit at Harrison Street, while northbound drivers should use the Alaskan Way exit.

The Sixth Avenue and Royal Brougham Way on-ramps will also close at 9 p. m. Maintenance crews will conduct fire suppression testing, clean and mark drains, and fix lights during the closure. These tasks are critical for maintaining safety and efficiency in the tunnel. Travelers through downtown Seattle are advised to seek alternate routes to avoid delays.

For real-time traffic updates, motorists can use the WSDOT mobile app.