HNTB achieved the project goal — to design a movable bridge that would be open to traffic immediately after a minor earthquake and be closed to traffic for a limited time for repairs after a major earthquake — by implementing innovative ideas such as sunken caisson foundations, isolated trunnion frame and a collapsible center joint on the bascule spans.

Location: Seattle, WA

Client: King County Department of Transportation

Awards: Excellence in Structural Engineering Award; NCSEA First Place in the movable Span Category; NSBA National Recognition Award, ACED Project of the Year Award; APWA #1 Bridge Project; Roads & Bridge Top Ten Bridges