The Alaskan Way Viaduct Replacement Program consists of 30 projects led by the Washington State Department of Transportation, King County, the City of Seattle and the Port of Seattle. The Federal Highway Administration is a partner in this effort.
The Alaskan Way Viaduct, an elevated section of State Route 99 in Seattle, was built in the 1950s, and decades of daily wear and tear took a toll on the structure. The structure was weakened in the 2001 Nisqually earthquake, requiring emergency repairs. Because of the viaduct’s age and vulnerability to earthquakes, replacing it was critical to public safety. The Alaskan Way Viaduct Replacement Program consists of 30 projects that replace the viaduct and provide safety and mobility improvements to Seattle's central waterfront.
The state's viaduct replacement projects are estimated to cost $3.35 billion. Funding comes from state, federal and local sources, as well as the Port of Seattle and tolls.
People interested in learning about the design or construction of the new Alaskan Way surface street along Seattle's central waterfront should contact the City of Seattle's Office of the Waterfront.
South Access - Surface Street Connections: Completing surface street connections around the SR 99 tunnel's south portal by Seattle's stadiums. New Alaskan Way: A new Alaskan Way surface street along Seattle's central waterfront that provides multimodal connections between SR 99 and downtown.
The SR 99 Tunnel: A two-mile-long tunnel beneath downtown Seattle. Battery Street Tunnel and North Surface Streets: Decommissioning the Battery Street Tunnel and rebuilding three blocks of Seventh Avenue North in South Lake Union. Viaduct Demolition: This project removed the Alaskan Way Viaduct along Seattle's central waterfront after the SR 99 tunnel opened. Full demolition began in February 2019 and the final segment of the viaduct was removed in November 2019. This work was part of the Battery Street Tunnel and North Surface Streets project contract. Holgate to King Street: This project built a mile-long stretch of new SR 99 highway near Seattle’s stadiums, replacing the Alaskan Way Viaduct's southern mile. The project also built an overpass near South Atlantic Street that allows traffic to bypass train blockages near Seattle’s busiest port terminal. The project ran from 2011 to 2014, with a budget of $347.7 million.
The view of Seattle's central waterfront before and after the SR 99 tunnel opened and the Alaskan Way Viaduct was demolished.
This page contains documents related to the Alaskan Way Viaduct Replacement Program's environmental review and analysis. The final environmental impact statement (final EIS) describes the permanent effects, construction effects, cumulative effects, and proposed mitigation for the project's proposed alternatives for construction.
1051 Building Demolition - March 2023
In fall 2022, WSDOT discovered that the building it owns at 1051 First Avenue South, Seattle WA 98134 contains serious structural deficiencies. Subsequent inspections determined that the building is unsafe for occupancy. WSDOT is now planning to demolish the building in 2023, and replace the existing sidewalk adjacent to the building along First Avenue South.
WSDOT has determined that this proposal will not have a probable significant adverse impact on the environment. An environmental impact statement (EIS) is not required under RCW 43.21C.030(2)(c). This determination was made based on review of the findings in the SEPA environmental checklist and supporting documents on file with the lead agency.