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SR-99 Tunnel North Access Connection

SR-99 Tunnel North Access Connection

Part of the Alaskan Way Viaduct Replacement Program
Location
Seattle, Washington
Client
Washington State Department of Transportation
Designer
Washington State Department of Transportation
Contract Value
$41,600,000
Completion Date
2016
Market Sector
Roadways & Bridges
Capabilities
Self Performance
The Washington State Department of Transportation awarded a $41.6 million contract to Atkinson for the SR-99 Tunnel North Access Connection project.
 
As part of the Alaskan Way Viaduct replacement program, the Atkinson team constructed the SR-99 tunnel’s north access entrance and exit roadways from the portal structure at Harrison Street to north of the Mercer Street bridge. The team also built on- and off-ramps at Republican and Harrison streets and extend Sixth Avenue North from Harrison Street to Mercer Street.
 
Once the new roadways and bridges were complete, the team demolished the existing SR-99 bridge over Broad Street and brought the abandoned Broad Street retained cut alignment up to grade. As part of their scope, the team also installed traffic signal, illumination, and ITS systems, and relocated existing utilities, including water, storm, sewer, and high voltage electrical systems.