SEATTLE, WA The Washington State Department of Transportation is deep in the planning stages to demolish Seattle, Washington's, aging Alaskan Way Viaduct. A new online open house is now available to show what's ahead and give the public a chance to comment on the work to come.

Removing the seismically vulnerable viaduct will be the most visible change to Seattle's waterfront in decades. The demolition work starts soon after the new State Route 99 tunnel opens, which is estimated for early 2019.

WSDOT has successfully completed this type of demolition work before. In 2011, the viaduct's southern mile was removed and a new road built in its place.

"Demolishing this remaining portion of the viaduct will be more challenging than the southern mile because the roadway is so close to downtown streets," said Brian Nielsen, WSDOT Deputy Program Administrator, Alaskan Way Viaduct Replacement Program. "We'll work closely with the contractor to protect people and buildings, and minimize traffic disruptions as much as possible. We want to make sure drivers, pedestrians, bike riders and ferry riders can still get where they need to go during the estimated nine months of demolition work."

Before the new tunnel opens, WSDOT will move Alaskan Way to the west of the viaduct, which will allow traffic to move along the waterfront before and during viaduct demolition operations. 

SR 99 Tunnel Project background

The tunneling machine Bertha finished building the outer wall of the SR 99 tunnel in April 2017.

Seattle Tunnel Partners, the SR 99 tunnel contractor, is currently dismantling the 8,000-ton machine, building the roads inside the tunnel and installing operational systems inside the tunnel. 

When the tunnel is finished, WSDOT will permanently close the Alaskan Way Viaduct and build final connections on the south and north ends of the tunnel so it can open to traffic. After the tunnel opens, contractor crews will also decommission and fill in the Battery Street Tunnel and reconnect three surface streets at the north end of the tunnel.

Once the Alaskan Way Viaduct is removed, the Seattle Department of Transportation will start building a new, larger Alaskan Way as part of the renovation of Seattle's waterfront.