September 2010
- We have awarded the contract for the automated viaduct closure gates project. Construction is expected to begin in September.
- View photos of the Pier 48 warehouse demolition along Alaskan Way.
Construction is underway to replace the viaduct between S. Holgate and S. King streets
Understanding the proposed bored tunnel
The Alaskan Way Viaduct and seawall replacement is a program that includes components led by WSDOT, the City of Seattle, King County and the Port of Seattle. WSDOT is responsible for replacing the double-deck viaduct, which is part of State Route 99. The City is managing the Elliott Bay seawall project.
The southern mile of the viaduct, between S. Holgate and S. King streets, is being replaced with a new side-by-side roadway that has wider lanes, meets current earthquake standards and improves mobility for people and goods in the south of downtown area. The environmental assessment for this project was released in June 2008, and the Finding of No Significant Impact was signed by the Federal Highway Administration in February 2009.
For the viaduct's central waterfront section, between S. King Street and Battery Street, there is an ongoing environmental process that is reviewing three alternatives – previous cut-and-cover tunnel and elevated structure alternatives, and a bored tunnel alternative recommended in January 2009. A second Supplemental Draft Environmental Impact Statement, which analyzes the bored tunnel alternative and builds upon the previous review of other alternatives, will be published in fall 2010.
As part of the replacement program, WSDOT is making safety and mobility improvements in the corridor, and King County and the City of Seattle are planning transit, city street and waterfront improvements. Visit related projects to learn more.
Why is WSDOT
pursuing this program?
The Alaskan Way Viaduct plays a major role in sustaining our economy and maintaining our citizens' ability to travel to and through Seattle. However, the viaduct, along with the adjacent seawall, is at risk of failure from earthquakes (with unacceptable risk to lives as well as property) and irreversible loss of use from age and deterioration. The structure must be replaced.
View a simulation (YouTube) of what could happen to the viaduct if a strong earthquake were to shake the Puget Sound region (or watch non-YouTube version - requires Windows Media Player).
We continue to monitor and inspect the viaduct as we move forward with its replacement. In 2010 crews will install a system designed to automatically close the structure in the event of a moderate to severe earthquake.
Our Partners
This program is led by WSDOT in partnership with the Federal Highway Administration, King County, the City of Seattle and the Port of Seattle.
The End Result
The end result for this program will be the replacement of the Alaskan Way Viaduct and the Elliott Bay seawall.
Project Benefits
- Safety. We will create safe, seismically sound replacement structures for the viaduct and seawall.
- Traffic. Improvements to SR 99, city streets and transit would provide capacity in the transportation system for today and the future and improve access and mobility to and through downtown Seattle.
What is the project timeline?
We completed our first project - column safety repairs - in 2008, and crews moved electrical lines off of the southern mile of the viaduct in 2009.
Road and bridge construction to replace the viaduct between S. Holgate and S. King streets began this year. Construction on the replacement for the viaduct's central waterfront section is expected to begin in 2011. Visit the program timeline for more information.
Financial Information
The Alaskan Way Viaduct replacement projects are estimated to cost $3.1 billion.
| Alaskan Way Viaduct replacement projects |
2010 Cost estimate
(millions)* |
| S. Holgate Street to S. King Street (aka south end) viaduct replacement |
$483 |
| S. King Street to Battery Street (aka central) viaduct replacement - proposed SR 99 bored tunnel |
$1,960 |
| Central waterfront viaduct removal and new Alaskan Way |
$290 |
| Central waterfront construction mitigation |
$30 |
Other Moving Forward projects:
- Column safety repairs
- Electrical line relocation
- Battery Street Tunnel maintenance
- Construction mitigation for south end viaduct replacement |
$181 |
| Prior Environmental Impact Statement, right of way and design costs |
$164 |
| Total |
$3,108 |
| *All costs are in year of expenditure dollars. |
In 2010 Governor Gregoire established a Program Oversight Committee to serve as a single point of accountability for cost and schedule issues related to the Alaskan Way Viaduct and Seawall Replacement Program.
State funding
The viaduct replacement projects have $2.4 billion in committed funding from the state gas tax and federal sources:
- 2005 Gas Tax (Partnership Funding) - $1,559.4 million
- 2003 Gas Tax (Nickel Funding) - $253.1 million
- Other State Funds - $247.4 million
- Federal Funds - $339.8 million
- Local Funding - $6.5 million
To fill the funding gap, the 2009 Legislature stated the finance plan must include no more than $400 million in toll funding.
The Port of Seattle also committed $300 million to the replacement program. In April 2010 Governor Gregoire signed an agreement with the Port for this funding.
How can I get more information?
Contact:
KaDeena Yerkan, Communications Officer
WSDOT
999 Third Ave., Suite 2424
Seattle, WA 98104
Phone: 206-805-2846
Email: viaduct@wsdot.wa.gov
Program Hotline: 1 - 888 - A W V - LINE (298-5463)
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