Welcome to your headquarters for viaduct-related traffic information. Major traffic changes are highlighted on this page. To your left are links to a full list of closures, traffic cameras, and other resources to help you find your way. You can also sign up to receive weekly emails about upcoming detours and closures.
SR 99 corridor
SR 99 is reduced to two lanes in each direction between Valley and Harrison streets.
Mercer Street is reduced to two eastbound lanes between Fourth Avenue North and Ninth Avenue North.
Friday, May 31
Crews will close Taylor Avenue North between Denny Way and John Street from 7 a.m. to 6 p.m.
Through summer 2013
South Jackson Street is … more
SR 99 and Mercer street are open again after a weekend closure to complete work as part of the West Phase of the Mercer Corridor project. The closure was in preparation for demolishing the east half of the SR 99 bridge over Mercer Street and widening Mercer Street between Fifth Avenue North and Dexter Avenue North.
A new configuration of SR 99 and Mercer Street is now in effect and travelers can expect the following changes to the corridor:
Mercer Street reduced to two eastbound … more
Contractor crews for the Washington State Department of Transportation recently began work to bring down and replace an elevated section of State Route 99 just south of the West Seattle Bridge. The bridge was built as a temporary structure back in 1959 and needs to be replaced. When they finish, they’ll leave Seattle’s SODO neighborhood with a stronger concrete bridge better equipped to withstand the test of time.
In late February, crews shifted traffic to the west side of … more