Thursday is when SDOT and WSDOT are usually out with construction-related traffic alerts for the next week – and for starters, we just got the plan for the Spokane Street Viaduct Widening Project, in its final weeks. Some overnight, one-direction closures are coming up – read on for the full list:

All eastbound travel lanes on the Spokane Street Viaduct will be closed at First Avenue S overnight Friday, August 3, from 10 p.m. until 5 a.m. on the following morning. During the closure, all eastbound traffic will exit at the First Avenue S off-ramp. Motorists wishing to access the I-5 or Columbian Way on-ramps can continue eastbound on the lower/surface S Spokane Street to Sixth Avenue S, where they can connect to the ramps.

The westbound travel lanes of the Spokane Street Viaduct between I-5 and SR 99 will be closed for two nights the following week, Monday, August 6, and Tuesday, August 7, from 10 p.m. both nights until 5 a.m. the following mornings.

Calendar of Upcoming Project Traffic Impacts:

Thursday, July 26 – Friday, July 27

· Southbound traffic on E Marginal Way S will jog to the west at S Spokane Street before returning to E Marginal Way S both nights form 10 p.m. until 5 a.m. the following morning.

Monday, July 30 – Thursday, August 2

· The eastbound First Avenue S off-ramp will be closed for four consecutive nights from 10 p.m. each night until 5 a.m. the following morning. The Fourth Avenue S off-ramp will remain open.

Friday, August 3

· The eastbound travel lanes of the Spokane Street Viaduct will be closed at First Avenue S overnight from 10 p.m. until 5 a.m. Saturday morning. During the closure, all eastbound traffic will exit at the First Avenue S off-ramp. Motorists wishing to access the I-5 or Columbian Way on-ramps can continue eastbound on the surface/lower S Spokane Street to Sixth Avenue S, where they can connect to the ramps.

Monday, August 6

· Northbound travel on First Avenue S will be closed overnight from 10 p.m. until 5 a.m. the following morning. Traffic will be detoured eastbound on surface/lower S Spokane Street and then northbound on Fourth Avenue S.

Monday, August 6 – Tuesday, August 7

· The westbound travel lanes of the Spokane Street Viaduct between I-5 and SR 99 will be closed from 10 p.m. both nights until 5 a.m. the following morning. Possible detour routes can be found on the project website, located at www.seattle.gov/transportation/spokanestreet.htm.

Tuesday, August 7

Southbound travel on First Avenue S will be closed overnight from S Horton Street to S Spokane Street from 10 p.m. until 5 a.m. on Wednesday morning. Southbound traffic will be detoured to Fourth Avenue S at S Horton Street.

4:41 PM UPDATE: In comments, David pointed out that if WSDOT went ahead with its “close the southbound Alaskan Way Viaduct Sun-Thurs nights TFN” plan on August 6th and 7th, it could be even worse trouble for late-night drivers .. but it DOES appear, per this even-newer advisory, that the state will NOT close the southbound AWV/99 those nights – see here. (We will put together the usual “all closures day by day” mashup a bit later.)