With a Key Bridge Cracked and Closed, Seattle Considers Another Tunnel

Seattle officials "have broadened their West Seattle Bridge replacement process to consider a shallow tunnel in addition to more traditional bridge options expected from big engineering companies," according to an article by Mike Lindblom. 

"The Seattle Department of Transportation (SDOT) may also shift $2 million in federal money toward initial planning for a new corridor, instead of using that cash for downtown programs, such as commute-reduction incentives," according to Lindblom. 

"The city is racing to reinforce the 36-year-old bridge, which was closed March 23 due to rapidly expanding shear cracks in the massive concrete girders," reports Lindblom. "The structure, the busiest city-owned span, might collapse unless braced soon."

As detailed in the article, the proposed for a tunnel replacement for the West Seattle Bridge where it crosses the Duwamish Waterway south of Downtown Seattle would use an entirely different construction process than the tunnel boring process that delayed the completion of the city's new Highway 99 tunnel by several years before finally opening in 2019.

The idea's champion, Bob Ortblad, published the idea in a separate article for the weekly West Seattle newspaper.