WSDOT Projects

Replacing the Alaskan Way Viaduct has been a top priority for the State and the City of Seattle since the Nisqually earthquake damaged the structure in 2001. The following is a summary of how this effort has progressed.

2002

• WSDOT and the City of Seattle considered a list of 76 concepts and gradually narrowed down the list to five alternatives for further consideration.

2004

• The Draft Environmental Impact Statement (EIS) includes evaluations of five alternatives: a rebuilt viaduct, a new aerial structure, a single-level cut-and-cover tunnel, a bypass cut-and-cover tunnel, and a six-lane surface boulevard.
• WSDOT, the City of Seattle, and the Federal Highway Administration selected the cut-and-cover tunnel as the preferred alternative. The rebuild alternative was carried forward as an alternate option if it was determined there was not enough funding for the tunnel.

2005

• Engineers completed further design work on the tunnel and rebuild alternatives.

2006

• “Rebuild alternative” renamed the “elevated structure alternative” to better represent changes made to the design since the Draft EIS was published.
• The Washington State Legislature passed legislation requiring an expert review panel to study the feasibility of both alternatives.
• As a result of the review panel’s report, WSDOT updated cost estimates for both alternatives to adjust for rising inflation rates and worldwide increases in construction material costs.
• The state legislature directed the Seattle City Council to adopt an ordinance stating their preferred option. The Council reaffirmed its support of a tunnel.
• WSDOT released a Supplemental Draft EIS to provide more detailed information on the two alternatives and potential construction plans.
• Governor Gregoire called for a vote by the citizens of Seattle.

2007

• Advisory vote held in Seattle, calling for an up-down vote on a surface-tunnel hybrid and the elevated structure. Both measures received a majority “no” vote.
• WSDOT and the City move forward with critical safety and mobility improvements (pdf 665 kb) to the Alaskan Way Viaduct. The projects will repair or replace more than half of the viaduct, and will fit with the chosen design for the central waterfront.
• WSDOT begins a collaborative process with city and county officials to determine the replacement for the central waterfront portion of the viaduct.