On Friday, Oct. 21, the State Route 99-Alaskan Way Viaduct will close for nine days.

The nine-day closure of the viaduct will be the longest ever for a Seattle-area highway. With one of the major north-south highways through Seattle closed, drivers from across the Puget Sound region will be significantly affected by the closure. Even drivers who commute from Lynnwood and Bellevue will see increased congestion as the nearly 110,000 vehicles that use the viaduct daily look for somewhere else to go.

Drivers are strongly encouraged to plan ahead, get familiar with commute options and allow extra time to reach their destinations. For those who have a choice, options such as vanpooling, carpooling or other forms of transportation can help avoid long delays.

WSDOT finished building the first of two side-by-side bridges that will replace the viaduct’s southern mile. On Oct. 21, contractors will close SR-99 and begin demolishing part of the viaduct. When SR-99 reopens to traffic on Oct. 31, both directions through SODO will travel on the new bridge. Workers can then finish demolishing the viaduct’s southern mile without disrupting traffic on SR-99, and begin building the second new bridge.

For more information and construction updates, go to www.wsdot.wa.gov.