|Project Sponsor / Borrower
Washington State Department of Transportation (WSDOT)
City of Seattle
Port of Seattle
The Alaskan Way Viaduct is an elevated section of
State Highway SR 99, one of two major North-South corridors
in the City of Seattle. The viaduct runs above Alaskan
Way along the Elliott Bay waterfront, from the Belltown
Battery Tunnel in the north to South Nevada Street in
the south. In 2001, the viaduct was damaged by the Nisqually
Earthquake, and although immediate repairs were made to
reopen the facility, it became apparent that the viaduct
was nearing the end of its useful life and needed to be
In January 2009, WSDOT, King County and the City of Seattle announced the Alaskan Way Viaduct and Seawall Replacement Program, which comprises two major projects and other related improvements.
- First is the South end viaduct replacement, where
a side-by-side roadway that will have wider lanes and
meet seismic safety requirements will replace the existing
viaduct section between South Holgate and South King
- Second is the replacement of the Central Waterfront viaduct section, which runs between South King Street and the Belltown Battery Tunnel. This section will be replaced with a bored tunnel underneath downtown Seattle connecting the new SR 99 roadway south of downtown and Aurora Avenue in the north.
- Other related improvements include repairs and enhancements of infrastructure components along the existing viaduct, specifically strengthening of viaduct columns in Pioneer Square; relocating of electric lines along the south end; decommissioning of the Battery Street Tunnel; a new Alaskan Way surface street along the Central Waterfront; and addition of traffic technology to SR 99.
Total - $3.137 billion
- South end viaduct replacement - $351.0 million
- Central waterfront viaduct replacement (bored tunnel) including north and south access and new north surface street connections - $2,053.2 million
- Central waterfront viaduct removal, new Alaskan Way surface street, and decommissioning of the Battery Street Tunnel - $291.7 million
- Environmental review, design, and ROW - $163.7 million
- Other projects and construction mitigation - $202.9 million
- Program management - $75.0 million
Federal funds - $787.2 million
State funds - $2.054.1 billion
- 2005 Gas Tax (Transportation Partnership Program) - $1,523.0 million
- 2003 Gas Tax (Nickel Funding) - $326.3 million
- Other State Funds - $4.8 million
- Tolls - $200.0 million
Local Funds - $28.4 million
Port of Seattle - $267.7 million
|Project Delivery / Contract Method
- Seattle Tunnel Partners - A joint venture of Dragados USA and Tutor Perini Corp. The team also includes Frank Coluccio Construction, Mowat Construction, and HNTB Corp.
|Project Advisors / Consultants
|Duration / Status
- South end viaduct replacement - Construction was completed in stages between 2009 and 2014.
- SR 99 tunnel - Initial construction activities began in fall 2011. The tunnel boring machine began operation in July 2013 and stopped while undergoing repairs from December 2013 - December 2015. It is expected to complete operation in February 2017. Related south and north tunnel portal access projects are underway and anticipated to be complete in 2017. Project completion is scheduled for third quarter 2018.
- The Alaskan Way Viaduct is a critical project included
among "at risk structures" emphasized in the State Legislature's
Transportation Partnership Program (2005), supported
by a second increase in the state's gas tax over a period
of two years.
- The project will use $200 million in toll revenue, which will capture the synergy from other recent tolling projects in Washington State.
|Related Links / Articles
Media Relations, Alaskan Way Viaduct Replacement Program
Tel: (206) 805-2871