Washington State Department of Transportation maintenance crews will close the southbound lanes of the SR 99 tunnel from 11 p.m. Friday, April 12, to 9 a.m. Saturday, April 13, to ensure tunnel systems are running properly.
Similar to owning a new car, it is important to keep the tunnel systems maintained to keep up with the warranties. During this maintenance closure, crews will clean the tunnel and check:
- Jet fans
- Fire detection
- Overhead signs
Maintenance closures of the tunnel are scheduled monthly, in alternating directions. In May, crews will close the northbound lanes.
Drivers who use the tunnel should plan alternate routes during the closure. Before heading out the door, check the latest road closures on the WSDOT app and by following the WSDOT Traffic Twitter feed.