Demolition of the southern mile of Seattle's Alaskan Way Viaduct begins on October 21, 2011.

  • By Jennifer Ott
  • Posted 3/07/2012
  • Essay 10049
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On October 21, 2011, construction crews begin demolition of the southern mile of the Alaskan Way Viaduct in Seattle. After more than 10 years of study, debates, votes, and intergovernmental negotiations, work finally commences on replacing the viaduct, which was damaged in the 2001 Nisqually earthquake. This particular project's genesis dates to 2007, when the public rejected both of the replacement options then under consideration. In the wake of the double defeat at the polls, state, county, and city officials came together to make a list of projects that could be done while the discussion about replacing the viaduct continued. Among these "Moving Forward" projects is the removal of the S King Street to S Holgate Street section of the viaduct. After four years of planning and preparation, it takes just about a week to take down the southern mile of the structure.

After the dust settled from the February 28, 2001, Nisqually earthquake, many people heaved a sigh of relief that the Alaskan Way Viaduct, the elevated portion of State Route 99 through downtown Seattle, had not collapsed. Though the quake was a strong one, the depth of its epicenter and its relatively short duration left the viaduct damaged but still standing.

Already under study for replacement due to its age and dissatisfaction with its effect on Seattle's waterfront district, after the earthquake the viaduct became the focus of a concerted effort to determine how to replace it. The first round of studies and discussions took about 6 years and led to the development of two options, a cut-and-cover tunnel along the waterfront and a replacement viaduct. City leaders favored the tunnel because it removed the noisy imposing viaduct from the waterfront district, reconnecting the neighborhood with downtown and opening the area to redevelopment. State officials preferred a replacement viaduct because it offered a less expensive and less risky solution. In a March 13, 2007, advisory vote, Seattle voters rejected both options.

Moving Forward

While the state, county, and city departments of transportation developed new options for replacing the viaduct that addressed concerns raised by opponents of the defeated options, Governor Chris Gregoire (b. 1947), King County Executive Ron Sims (b. 1948), and Seattle Mayor Greg Nickels (b. 1955) met to determine what could be done to prepare for whichever option would eventually be chosen.

The three officials put together a set of "Moving Forward" projects that needed to be done regardless of what replaced the viaduct. These projects included moving electric lines off the viaduct between S Massachusetts Street and Railroad Way S, reinforcing the viaduct between Yesler Way and Columbia Street to stabilize the structure while construction progressed, safety upgrades to the Battery Street Tunnel just north of the viaduct, improvements to transit lines that passed through the construction site, and replacement of the viaduct between S King Street and S Holgate Street with a new elevated roadway.

Work on the Moving Forward projects began in September 2008. After the required environmental review, preparations for the demolition of the southern section of the viaduct began in February 2009. Skanksa USA, a New York City-based civil engineering firm that won the contract for the project, began preparing a detour route around the demolition site. The route began at the existing southbound off-ramp and a new northbound on-ramp at First Avenue S, near CenturyLink Field, and ended at a new overpass for State Route 99 crossing over the railroad tracks previously bridged by the viaduct. It included a new siding road just east of the viaduct that took up part of First Avenue S.

Demolition crews took down the existing First Avenue South on-ramp on a weekend in February 2011. A new on-ramp was built over a southbound lane of First Avenue S and the new siding road was built. In May workers realigned the surface portion of State Route 99 between the Spokane Street Viaduct and the end of the Alaskan Way Viaduct to make room for construction of the new southbound overpass.

Once construction of the new overpasses had progressed as far as possible with the viaduct in place, the crews were ready to close the viaduct and reroute traffic. In October 2011, the state Department of Transportation closed the viaduct for nine days to begin demolition of the southern portion and complete construction of the southbound overpass. The viaduct closed after rush hour on Friday, October 21, 2011, and workers driving excavators with attachments for breaking up concrete began demolishing the structure.

Viaduct Roller Derby

The next day, the Department of Transportation hosted a day of activities to bid the viaduct adieu. Before the general public walked onto the viaduct, the winners of a contest for the best answer to the question "What would I do with 30 minutes on the Alaskan Way Viaduct?" got to spend 30 minutes on the closed roadway. Out of 600 entries, the Rat City Rollergirls and the Seattle Cossacks, a motorcycle stunt team, had won the contest. The Rollergirls asked to use the viaduct for a roller derby bout and the Cossacks wanted to perform their stunts on the viaduct decks.

The Cossacks had a long history of being involved with the opening of transportation projects. According to one of the Cossacks, the group led the first crossings of the original Tacoma Narrows Bridge and the old Spokane Street Bridge.

After the Rat City Rollergirls and the Cossacks spent their time on the viaduct, the general public was allowed to walk the roadway and say their own farewells while demolition work progressed to the south. Despite rainy weather, a crowd of thousands walked the structure. Some came to celebrate its demise, while others came, if not to mourn, to at least mark its passing. A handful of protesters held signs decrying the climate change effects of building roads for cars and trucks rather than supporting alternative transportation methods.

For nearly a week, excavators tore away at the viaduct. Rebar that had laced the deck and columns stuck out in all directions and fell into heaps of rubble below. Spectators gawked at the scale of the project and marveled at the views that opened up as the viaduct fell away. Plans called for nearly all of the concrete and rebar to be recycled and reused. Terminal 25 served as a processing center for the 3,500 truckloads of concrete hauled away from the demolition project. The concrete was crushed and stored for use in the tunnel planned to replace the viaduct. A local recycling company hauled away the rebar for reuse elsewhere.

Local media had predicted "Viadoom" when the viaduct closed to traffic, pushing its 110,000 daily vehicles to Seattle's city streets and Interstate 5. The worst case scenarios of gridlock did not materialize, but the closure combined with rainy weather did lead to large traffic jams toward the end of the week.

Once rubble was cleared away and connections made between the siding road and the new overpass, the detour was ready to open to the public. Drivers wended their way along the unfamiliar path through the construction zone while crews finished up demolition of the viaduct south of S King Street. The Department of Transportation planned to continue work in 2012 on the new infrastructure that would carry traffic over the railroad tracks and between the waterfront and inland streets. Construction of a deep-bore tunnel to replace the remaining section of the viaduct began in 2013. However, that December the tunnel-boring machine ran into problems and was halted for two years while repairs were made. Tunnel boring was eventually completed in April 2017 and, after another two years of work to build the two-level highway inside it, the new tunnel opened in February 2019. The remaining viaduct had already closed to traffic on January 11, 2019, with plans calling for it to be demolished once the tunnel was in operation. 


Gerry Spratt, "With Viaduct Closed, Seattle Braces for Messy Commute," Seattle Post-Intelligencer, October 23, 2011 (; Phuong Le, "Seattle Survives Day 1 of 'Viadoom' Traffic," Ibid., October 24, 2011; "Official: Seattle Viaduct to Open Mid-Day Saturday," The Seattle Times, October 28, 2011 (; Mike Lindblom, "Thousands Say Goodbye to Viaduct," Ibid., October 22, 2011; Lindblom, "The Beginning of the End for the Viaduct," Ibid., February 18, 2011; Susan Gilmore, "Relocating Electrical Lines on Viaduct Begins," Ibid., September 12, 2008; S. L. Kramer and M.O. Eberhard, Seismic Vulnerability of the Alaskan Way Viaduct: Summary Report (Seattle: Washington State Transportation Study, 1995); "Alaskan Way Viaduct Replacement Project: 2010 Supplemental Draft Environmental Impact Statement, Appendix S: Project History Report," Washington State Department of Transportation (WSDOT) website accessed December 8, 2011 (; "Alaskan Way Viaduct Replacement – Timeline," WSDOT website accessed March 4, 2012 (; Hilary Bingman, "Alaskan Way Viaduct Contest Winners Revealed: Rolling Together Through Seattle’s Past and Present Culture Clash," WSDOT Blog, October 21, 2011, WSDOT website accessed March 4, 2012 (; Noel Brady, "Viable Opportunities in Viaduct Recycling," WSDOT Blog, December 12, 2011, WSDOT website accessed March 7, 2012 (; Mike Lindblom, "Bertha to Beef Up by 86 Tons," The Seattle Times, June 17, 2014, p. A-1; Daniel Beekman and Joseph O'Sullivan, "Bertha's Stall Leaves Politicians Stuck for Answers," Ibid., January 4, 2015, p. A-1; "Alaskan Way Viaduct Replacement Program," Washington State Department of Transportation website accessed September 22, 2014 (; Mike Lindblom, "New Bertha Start Date: Nov. 23," The Seattle Times, July 17, 2015, p. A-1; Lindblom, "Tunnel Delayed Yet Again, Until 2019," Ibid., July 22, 2016, p. A-1; Online Encyclopedia of Washington State History, "Alaskan Way Viaduct, Part 4: Replacing the Viaduct" (by Jennifer Ott), (accessed February 6, 2019).
Note: This essay was updated on September 22, 2014, January 6 and July 29, 2015, July 29, 2016, and February 6, 2019.

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