The Alaskan Way Viaduct Replacement Program is led by the Washington State Department of Transportation in partnership with the Federal Highway Administration, King County, the City of Seattle and the Port of Seattle. Each jurisdiction is responsible for its own projects’ management, environmental work, design and construction.
The state is responsible for leading or funding 30 of the projects that will work together to reshape the SR 99 corridor. Construction on our first project started in 2007, when crews stabilized four viaduct columns that settled following the 2001 Nisqually Earthquake. Since then, 21 projects that are led or funded by the state have been completed, with several more in progress or set to break ground soon.
Seattle Tunnel Partners monthly schedule
Our contractor, Seattle Tunnel Partners, is responsible for designing and building the SR 99 tunnel. Our contract with STP includes a number of elements. In addition to boring the tunnel and building the highway within it, STP is responsible for building highway ramps and other connections at the north and south ends of the tunnel. They are also constructing buildings at each tunnel portal to house lighting, ventilation and other systems needed to operate the tunnel. Although tunnel boring is on hold, approximately 70 percent of this work had been completed as of December 2014.
STP submits an updated schedule to WSDOT each month. Like all large construction projects, the schedule for this project changes frequently. It also does not account for the contractor’s efforts to speed up work, an issue that is explained further in this post. Summary versions of STP's most recent schedules are posted below: