Commuters through downtown Seattle should know about upcoming lane, ramp and tunnel closures on SR 99 this week and weekend.

Every night this week between 9 p.m. and 5 a.m., the northbound off-ramp to Alaskan Way and downtown Seattle will be closed while crews install railings. The Washington State Department of Transportation advises drivers trying to access the waterfront and stadium district to use East Marginal Way, 1st Ave. S. and other surface streets. This off-ramp is the only way to exit SR 99 traveling northbound between the West Seattle bridge and the north end of the tunnel in South Lake Union. 

At the north end of the tunnel, Seventh Avenue North, formerly known as Aurora Ave. North, will be closed from 9 p.m. to 5 a.m. Monday through Thursday. This one is a little more complicated. WSDOT reports, "Northbound lane closed Tuesday and Thursday nights; southbound closed Monday and Wednesday nights." The reason is to install temporary lighting.

The most significant closure is Friday night into Saturday morning, when the southbound direction of the SR 99 tunnel under Seattle will close for the tunnel’s first checkup. The closure begins Friday night at 11 p.m. The tunnel is scheduled to reopen Saturday at 8 a.m. WSDOT crews will check the systems inside the tunnel like ventilation fans, cameras and fire detection. There will be one of these closures every month. In May, the northbound lanes will close, those dates have not been determined yet. 

Join the Seattle Tunnel Traffic group on Facebook to ask questions and share concerns or ideas regarding the new SR 99 tunnel under downtown.