Alaskan Way Viaduct

Seattle, Washington

Alaskan Way started as a rail yard 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 automobiles, the City built the elevated viaduct over the rails in 1953, named it State Route 99 and launched a major north-south thoroughfare in Seattle. Today, traffic on the Alaskan Way Viaduct is down from its roughly 100,000 daily vehicle peak, though recent rates are difficult to track. 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.

Alaskan Way Viaduct today cutting off downtown from waterfront. Source: Wikimedia Commons

In 2006, the City of Seattle, the State of Washington and the Federal Highway Administration agreed on a cut-and-cover tunnel as 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 pursue, 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.

In 2007, after a study by the University of Washington found that damage from continued post-earthquake settling will further harm the structure, the researchers 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.

With the two expensive options off the table, Cary Moon and the People's Waterfront Coalition capitalized on momentum for a surface boulevard and transit alternative. The organization envisioned an open, landscaped boulevard with investment in increasing transit on nearby corridors. This human-scale urban street would have re-opened the waterfront to the community and restore the shoreline, supporting a vibrant urban atmosphere. Further development along the newly opened 22 acres of public land on Seattle's downtown waterfront could have given way to new parks, beaches, and development that could have ultimately save the city years of construction delays and billions of dollars. "If you try to build your way out of congestion," said Moon, "you'll ruin your city or go broke trying."

Seattle Alaskan Way Viaduct boulevard
Rendering of Alaskan Way replaced with boulevard, connecting city to waterfront & opening space for development. Source: Oregon Live

In 2009, despite best efforts to promote the surface boulevard option and focus investment on serving local mobility, the State of Washington, along with the City of Seattle and King County, decided to replace the viaduct with a deep-bore underground bypass tunnel. Work to design the road and build the tunnel boring machine in Japan got underway quickly. The boring machine at 57’ diameter is the largest ever attempted in the world. However, the $3.1 billion project is currently at a standstill after the drilling machine broke down in December 2013 due to failed seals and a damaged main bearing. The machine broke just 1,023 feet into a 9,270-foot journey. A repair timetable estimates digging to resume in March 2015. Delays are not the only setback of the breakdown.

The tunnel choice was always controversial, due to high risks, questionable funding, and poor fit for providing access to and from the regional economic center of downtown Seattle. WSDOT and contractor Seattle Tunneling Partners are currently debating who should cover the repair costs estimated to add $125 million to the project budget. These repair costs include a large pit and concrete pad to fix the machine. A local group Democracy Workshop filed suit in federal court in March 2014 naming WSDOT, the City of Seattle and the Federal Highway Administration as defendants. Democracy Now claims the pit is a “project within a project” that should not move forward without a further environmental impact study. Washington State Secretary of Transportation said she could not say with 100 percent certainty that the tunnel project will be finished as there is a possibility, albeit small, that the machine is unable to be repaired. Furthermore, if drilling does resume March 2015, the project still has over 8,000 feet to complete, leaving plenty of opportunity for further breakdowns, delays and additional costs. It is unclear if and when the project will be completed, and who will pay additional costs. In the meantime, the damaged viaduct structure is still in use.

The good news is that regardless of what happens with the stalled tunnel, the City of Seattle is proceeding with the plans for a stunning new civic waterfront, including a 4-lane urban street, parks, water access, habitat improvements, and better connections to downtown neighborhoods.

By the beginning of the summer of 2016, over one-quarter of the future Highway 99 tunnel had been excavated. The path of the tunnel digging machine is continuing toward the Pike Place Market, and it is currently located in Zone 4 of 10 the total zones. Reaching this zone means that the machine is going past the foundation of the northbound SR 99 off-ramp to Seneca Street. As of July 14 2016, Bertha has traveled 3,088 of 9,270 feet with 467 of 1,426 total rings built.

Seattle Alaskan Way Viaduct
Alaskan Way Viaduct today. Source:
Seattle Alaskan Way Viaduct boulevard
Vision of a revitalized Seattle waterfront in future. Source: Rethink 81

Check out Waterfront Seattle's events page to stay up to date on Seattle's Alaskan Way Viaduct plans.

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