As you know, the Spokane Street Bridge is currently out of commission. To ride or walk from West Seattle across the Duwamish River it is now necessary to use the First Avenue South Bridge or the South Park Bridge.
Here is a bike detour route from our Resources page that we recommend. A bit longer but with less vehicle traffic and lower vehicle speeds than SDOT’s detour route. Most of it is signed as a bike route, but signage is lacking at the foot of the First Avenue S Bridge. The RideWithGPS route has audio and printable cues for turns. https://ridewithgps.com/routes/34419471
Here is a current video of that route, from John Graham: https://youtu.be/eLyQXbQ7xfw
More than 2-1/2 years ago, we asked SDOT to make permanent improvements for a safe detour route to the Spokane Street Bridge for just this sort of predictable and likely event. Our allies at Duwamish Valley Safe Streets, Seattle Neighborhood Greenways, and Cascade Bicycle Club joined us in these requests for the Reconnect West Seattle work. SDOT did not respond, except for minor improvements on 6th Ave S and one track crossing. Now it is an emergency. SDOT is putting together a temporary detour route with temporary protections, and the City is working with King County Metro to offer free bus and water taxi rides for all who need alternatives. While hoping for a more pro-active work for permanent improvements, we are grateful for the current effort. The temporary work and the transit fare relief give options for people biking, and provides a valuable opportunity to test out the planned bike lanes for part of West Marginal Way SW, and bike routes in Georgetown and SODO.
If you try either or both of these routes, or have another to suggest, please let us know what you think.