press release:
The Fauntleroy Expressway (at the east end of the West Seattle Bridge) will be closed from Saturday night, February 18, until midnight on Sunday, February 19. To get to the West Seattle Bridge, traffic will be directed to the Delridge on-ramp because the intersection of SW Avalon Way and SW Spokane Street will be restricted. The West Seattle Bridge and the Spokane Street Viaduct will remain open. First Avenue S will be closed at S Spokane Street.

Fauntleroy Expressway (from 35th Avenue SW to Delridge Way SW): The Fauntleroy Expressway will be open from 5 a.m. to 9 p.m. on Saturday, February 18, and will be closed from 9 p.m. on Saturday until 11:59 p.m. on Sunday, February 19. Detours will be the same as during the week—eastbound traffic on Fauntleroy Way SW will be detoured at 35th Avenue SW and will be directed to the West Seattle Bridge via SW Genesee Street and Delridge Way SW. Westbound traffic on the West Seattle Bridge will be directed off the bridge at the Delridge Way SW off-ramp.

SW Avalon Way: SW Avalon Way will be closed at SW Spokane Street from 6 p.m. Saturday, February 18, until 11:59 p.m. Sunday, February 19. During this period traffic will operate on Avalon the same as it has been during the daytime this week. Trucks and buses will be flagged through the intersection. Northbound general traffic will be detoured to eastbound SW Spokane Street, directed to perform a U-turn at 26th Avenue SW onto westbound SW Spokane Street, and then north on Harbor Avenue SW.

Spokane Street Viaduct (connecting West Seattle Bridge to I-5): One eastbound lane on the Spokane Street Viaduct will be closed at First Avenue S from 9 p.m. on Friday to 5 a.m. on Saturday. All lanes will remain open during the rest of the weekend.

First Avenue South (surface street): On Friday and Saturday nights, First Avenue South will be closed at South Spokane Street from 9 p.m. until 5 a.m. the following mornings. Eastbound lower S Spokane Street traffic will be allowed to continue east through the intersection. Northbound traffic will be detoured east at S Spokane Street to Fourth Avenue S. Southbound traffic on First Avenue S will be detoured at S Hanford Street.

These closures are for the Fauntleroy Expressway Seismic Retrofit Project and the South Spokane Street Viaduct Widening Project, both funded by the Bridging the Gap transportation initiative.