Overnight closures of SR 99 in downtown Seattle Sept. 22-25 for pavement work

Washington State Department of Transportation

Traffic Advisory

Drivers who use State Route 99 in downtown Seattle should be prepared to use alternate routes for up to four nights next week.

Weather permitting, contractor crews working for the Washington State Department of Transportation will close lanes on both northbound and southbound SR 99 overnight Monday, Sept. 22 through the morning of Friday, Sept. 26 between the West Seattle Freeway and South Atlantic Street.

Southbound closure details

  • Monday, Sept. 22 and Wednesday, Sept. 24 – All southbound lanes will be closed nightly 10 p.m. to 5 a.m. The Columbia Street on-ramp to southbound SR 99 will also be closed. Northbound SR 99 will remain open, but two of three lanes will be closed 10 p.m. to 5 a.m.

Northbound closure details

  • Tuesday, Sept. 23 and Thursday, Sept. 25 – All northbound lanes will be closed nightly from 10 p.m. to 5 a.m. The West Seattle Bridge on-ramp to northbound SR 99 will also be closed. Southbound SR 99 will remain open, but two of three lanes will be closed from 10 p.m. to 5 a.m.

During the closures, contractor crews will work on pavement repair, grinding, striping and installing traffic detection loops.

This is part of the SR 99 Spokane Street Bridge to Alaskan Way Viaduct Concrete Pavement Rehab project. Earlier this summer, the crews replaced and repaired more than 81 concrete panels. The project helps preserve this vital commuter and freight route by reducing bumps, cracks and provide a safer, smoother ride for drivers.