As first reported here two weeks ago, the city has set May 17th for the closure of the 1st Avenue South onramp to the West Seattle Bridge, as the Spokane Street Viaduct Widening Project goes into its next construction phase. Today the city has sent a news release reiterating that date, with a new detour map – read on for both:
The next major milestone in the South Spokane Street Viaduct Project (the structure that links the West Seattle Bridge to I-5) is the permanent closure of the First Avenue South on-ramp to the westbound lanes of the viaduct, tentatively scheduled for May 17. The ramp closure is required to widen the Spokane Street Viaduct to the north by approximately 41 feet. The new westbound on- and off-ramp will be constructed on First Avenue.
In the year and a half during which there will be no access to the Spokane Street Viaduct from surface streets in SODO, vehicles will be detoured to the low level swing bridge to get to West Seattle. Alternative routes are noted in the attached detour map. SDOT will be monitoring traffic flows along the detour routes following the closure to determine whether changes in signal timing or other measures are needed to keep traffic moving.
Beginning March 22, drivers should additionally plan for delays when the First Avenue South off-ramp from eastbound lanes of the viaduct is reduced to one lane for up to five months. On surface streets, First Avenue South, recently reduced to one lane for southbound traffic, will also be restricted to one lane for northbound traffic from Spokane to Hanford streets, also for up to five months. The exception is the weekend of March 27-28, when the Alaskan Way Viaduct is closed for inspection. During that weekend, two lanes on the ramp and northbound First Avenue will be open to improve access to downtown Seattle.
Here’s another look at the detour map. Though the type at the bottom says Metro reroute details are pending, Metro shared their plan with us by request the same day we published first word of the May 17th shutdown date – that story is here.