According to the Washington State Department of Transportation, the nine-day closure of the viaduct will be the longest ever for a Seattle area highway. Over 100,000 daily commuters who use the viaduct will be looking for options during the closing of SR99.
Northbound SR 99 between the West Seattle Bridge and South Royal Brougham Way will be closed around-the-clock beginning at 7:30pm Friday, Oct. 21 until 5:00am on Monday, Oct. 31, according to the WADOT. However, Northbound SR 99 between the South Royal Brougham Way on-ramp and the Battery Street Tunnel will open from 5:00am to 7:00pm, Monday through Friday for commuters, and for special events at CenturyLink Field during those nine days.
When 99 re-opens on Monday, October 31, according to the WSDOT, traffic in both directions through SODO will travel on the first of two new bridges being constructed.
In the meantime, you are encouraged to plan ahead, pack your patience, and familiarize yourself with detours and options. Allow extra time for congestion. And check out the WSDOT website for a map and more details