Viaduct demolition

Removing the Alaskan Way Viaduct

After the new State Route 99 tunnel opens to drivers, the Alaskan Way Viaduct along Seattle's waterfront will be removed to make way for a new surface street built by the City of Seattle. This project will help transform Seattle’s waterfront while removing a vulnerable structure from our road network.

Current view of the viaduct

Why remove the viaduct

The Alaskan Way Viaduct was built in the 1950s and was damaged in the 2001 Nisqually Earthquake. While it has been strengthened and is safe for daily use, it remains 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 built once the viaduct is gone.

Scope of work

Viaduct removal work is scheduled to begin in February 2019 and take about six months. The major elements of this project are:

  • Shifting Alaskan Way to the west of the viaduct (completed in October 2018).
  • 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 will be unavoidably disruptive. Our primary goal is to remove the viaduct safely and with as little disruption as possible to nearby people, property and businesses. The contractor, Kiewit, will follow a variety of standards and best practices as they design and conduct the work.

+ Work sequence and road closures

+ Method of work

+ Minimizing disruption

+ Access to Colman Dock

How to stay informed as work progresses

Join the mailing list! Sign up to receive viaduct removal, Battery Street Tunnel decommissioning and north surface street updates by email by entering your email address on our subscription page