Viaduct demolition

Removing the Alaskan Way Viaduct

WSDOT removed the Alaskan Way Viaduct from Seattle's central waterfront to make way for the City of Seattle's Waterfront Seattle Program. The viaduct was seismically vulnerable and demolishing it will help transform Seattle’s waterfront.

Wide angle view of machines demolishing the viaduct

Why remove the viaduct

Built in the 1950s, the Alaskan Way Viaduct was damaged in the 2001 Nisqually Earthquake. While it was strengthened and safe for daily use, the structure remained seismically vulnerable. The viaduct’s role in moving people into and through downtown Seattle will be replaced by the new SR 99 tunnel and a new Alaskan Way surface street now under construction.

Scope of work

Viaduct removal work began on Feb. 12, 2019 and concluded in November 2019. The major elements of this project were:

  • Shifting Alaskan Way to the west of the viaduct.
  • Removing the Alaskan Way Viaduct from South Dearborn Street to the Battery Street Tunnel.
  • Removing the Columbia and Seneca street ramps.
  • Building a new, temporary pedestrian bridge across Alaskan Way to Colman Dock.
  • Restoring the area where the viaduct once stood and then turning the space over to the City of Seattle's Waterfront Seattle Program.

Project goals

Removing a large concrete structure from a busy waterfront is unavoidably disruptive. Our primary goal was to remove the viaduct safely and with as little disruption as possible to nearby people, property and businesses. The contractor, Kiewit Infrastructure West Co., completed the work without any reportable injuries or significant damage to property, and while keeping Alaskan Way open.