Seattle's Alaskan Way Viaduct
The Alaskan Way Viaduct started as a railyard to accommodate the City's industrial needs along the waterfront of Elliot Bay in the 1880s. As the need for rail decreased with the rise of personal autmobiles, the City built the viaduct in place of the rails in 1953, renamed State Route 99 and became the major north-south thoroughfare in Seattle. Today, approximately 110,000 vehicles travel on the expressway, carrying 20-25% of downtown traffic. Studies conducted in the 1990s revealed the structure was reaching the end of its lifespan. Daily wear and tear, increasing age, salty marine air, and damage by the powerful Nisqually Earthquake in 2001 confirmed the weakening nature of the bridge, requiring costly emergency repairs and calling into question its long-term viability. The City of Seattle and the State of Washington agreed the viaduct must come down, but have been wrestling with how to replace structure ever since.
In 2007, after a study by the University of Washington found that damage from continued post-earthquake settling will further harm the structure, they recommended the viaduct be destroyed within 4 years. In January 2008, Governor Christine Gregoire announced that "no action" was not an option and by 2012 the viaduct would come down. At the time of this statement however, no decision was made for a specific replacement.
The City of Seattle, the State of Washington and the Federal Highway Administration agreed the cut-and-cover tunnel was the prime replacement option for the viaduct. In the event the tunnel exceeded cost estimates, an alternative to rebuild the elevated viaduct was provided as well, each with price tags of $4 billion or more. Washington State and the City of Seattle grew increasingly embittered with one another disagreeing over which replacement to use, calling for a referendum among voters to decide the best option. In March 2007, the people of Seattle strongly voted against both options, welcoming in a surface transit option.
With the two expensive options off the table, Cary Moon and the People's Waterfront Coalition have capitalized on momentum for a surface boulevard alternative. The organization envisions an open, landscaped boulevard with built in options for transit. This human-scale structure would re-open the waterfront to the community and restore the shoreline, supporting a vibrant urban atmosphere. Further development along the newly opened 335 acres of public land on Seattle's waterfront could give way to new parks, beaches, and development that could ultimately save the city years of construction delays and billions of dollars. "If you try to build your way out of congestion," says Moon, "you'll ruin your city or go broke trying."
Despite best efforts to promote the surface boulevard option, the City of Seattle, along with the county and state, replaced the cut-and-cover tunnel with a deep-bore underground tunnel option to reduce costs and traffic congestion, amidst constant criticism from local stakeholders as of January 2009. However, with Mike McGinn's victory in a landmark mayoral election in November 2009 provides some hope for the surface boulevard alternative to stay alive.
Washington State Deparment of Transportation Alaskan Way Viaduct Program Information Center
Federal Highway Administration Alaskan Way Viaduct Replacement Program Executive Summary
Seattle Department of Planning and Development Central Waterfront Homepage
Current AWV Corridor (WSDOT)
The Alaskan Way Viaduct, as seen from Elliot Bay (Wikipedia)
One of three proposed surface level alternatives (WSDOT)