Catastrophic failure planning for the SR 520 bridge

Abstract

The State Route 520/Evergreen Point Floating in Seattle, Washington, is vulnerable to windstorms and earthquakes and needs to be replaced. The Washington State Department of Transportation (WSDOT) recognizes the need to have a plan in place to manage traffic and communications if the SR 520 floating bridge were lost in such an event. The plan was developed in collaboration with regional jurisdictions, transit agencies, emergency responders, and businesses, as a toolkit of strategies that could be implemented quickly and effectively to benefit the region. WSDOT also invited engineers from Minnesota DOT to contribute to the plan by sharing their experience from I-35W bridge collapse and recovery. The main components of the plan are the Transportation Management Plan and the Communications Plan. A regional tabletop exercise focusing on a SR 520 catastrophic failure scenario helped to inform the development of the plan. The SR 520 Catastrophic Failure Plan provides a basis for WSDOT to prepare for a catastrophic bridge failure and for local jurisdictions to develop their own emergency response plans. © 2011 WIT Press.