On Jan. 13, 2009, in Seattle, WA, Governor Chris Gregoire, King County Executive Ron Sims and Seattle Mayor Greg Nickels signed an agreement to demolish the earthquake-damaged Alaskan Way Viaduct and build a 16.5-m- (54-ft-) diameter, four-lane, two-level, deep bored tunnel under downtown Seattle to be open to traffic in 2015 - requiring accelerated environmental, design and construction. This reversed a decision exactly one month earlier for two alternates that did not incorporate any tunnels, primarily because the predicted tunnel cost exceeded available funds. A stakeholders group of all interested parties rejected that decision and requested that a tunnel option be considered. What followed was an immediate groundswell of strong support for a deep-bored bypass tunnel, mostly from downtown Seattle business leaders and the Cascadia Center. The Washington State Department of Transportation (WSDOT) spent the next month intensely evaluating the deep-bore option for the city, state and county leaders who agreed with the consensus of the stakeholders and overcame funding constraints. With this decision, the WSDOT selected the deep bored tunnel for environmental documentation, design and construction on Jan. 13.
展开▼
