4:42 PM MONDAY: Nighttime traffic alerts are out for four of the next five nights because of surface-street work related to the West Seattle Bridge repairs. We got the first hint at this with an unexplained Metro detour advisory issued late last week, and obtained the full list of alerts from SDOT just now:

This week, crews will be installing safety measures beneath the West Seattle High Rise Bridge and Fauntleroy Expressway as a precaution for upcoming overhead work. Crews will need space to stage equipment beneath the bridge while equipment is being installed, leading to some late-night detours on SW Spokane St, West Marginal Way and East Marginal Way on certain nights this week.

Here is the full detour information for each night this week.

10 PM Monday, April 25 to 5 AM Tuesday, April 26:
Closure of eastbound Spokane Street Between Avalon Way & Delridge Way
Detour in place: Southbound on SW Avalon Way, east to SW Genesee St, North on Delridge Way SW

7 PM Tuesday, April 26 to 6 AM Wednesday, April 27:
Closure of southbound right lane of West Marginal Way.
Pedestrian path to be closed from 10 PM to 5 AM

10 PM Wednesday, April 27 to 5 AM Thursday, April 28:
Closure of East Marginal Way U-turn lane and right lane approaching the U-turn

10 PM Thursday, April 28 to 5 AM Friday, April 29:
Closure of westbound Spokane St between Delridge Way and Avalon Way
Detour in place: south on Delridge Way SW, west on SW Genesee St, northbound on SW Avalon Way

10 PM Friday, April 29 to 5 AM Saturday, April 30:
Closure of S Spokane Street to northbound East Marginal Way; closure of Northbound East Marginal Way at Spokane Street.
There will be a signed detour to Eastbound Spokane St.

6:42 PM TUESDAY: Updated above, with Wednesday night work added, and Thursday scope changed.