press release:
The westbound lanes of the Spokane Street Viaduct between I-5 and SR 99 were closed Monday through Wednesday nights this week, and now they will also be closed tonight (Thursday), from 10 p.m. until 5 a.m. tomorrow morning. This will close direct access to West Seattle via the Spokane Street Viaduct from both northbound and southbound I-5. (Motorists traveling southbound on SR 99 will still be able to access the off-ramp to the West Seattle Bridge.)

Southbound traffic from I-5 wishing to travel to West Seattle should detour by exiting I-5 at S Forest Street, turning right (northbound) onto Sixth Avenue S, then turning left (westbound) at S Lander Street, turning left again (southbound) at First Avenue S, turning right (westbound) at S Hanford Street, turning left (southbound) onto East Marginal Way S, and finally turning right (westbound) onto the lower S Spokane Street roadway and across the swing bridge to West Seattle. Northbound traffic from I-5 wishing to travel to West Seattle should exit the freeway at Sixth Avenue S, and then follow the same detour route outlined above.

Traffic changes for this weekend and next week will be announced shortly.