State Route 99 in Downtown Seattle will close entirely for three weeks this fall and, for some commuters, the pain will extend even longer.
Roadways must be realigned from the Alaskan Way Viaduct to the tunnel that replaces it.
The Washington State Department of Transportation held a news conference Thursday to get commuters thinking about the coming closure, even though the date is not yet known.
"We will give about a month's notice when we're ready to close the viaduct," said David Sowers of WSDOT.
Sowers said the contractor's schedule still calls for turning over the tunnel to the state late in August.
WSDOT hopes to open the new tunnel by Thanksgiving, allowing contractors to begin a six-month-long demolition of the viaduct.
A three-week closure will be longer than the 2016 closure during which the drill Bertha tunneled beneath the viaduct, and longer than the 2011 closure during which crews tore down the south end of the viaduct.
This fall, people who live in West Seattle and work downtown will see the effect on their morning commutes extended an additional seven to 10 days.
That's because building a new northbound off-ramp to downtown at Dearborn Street will take longer than other connection projects.
This weekend, the southbound lanes of the viaduct will close from 9 p.m. Friday to 6 a.m. Sunday between the Battery Street Tunnel and the West Seattle Bridge.
Workers will straighten a section of the roadway on southbound State Route 99 near the Atlantic Avenue exit in preparation for the roadway connections that will be made this fall.
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