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Seattle, Washington: Elevated Floating Bridge

City: Seattle
Country / US State / US Territory: Washington
Type of Solution: Bridge
Climate Impact: Hurricanes and Extreme Storms
Social Value Created: Diverse Transportation; Public Health and Safety; Active Living and Recreation

The Washington State Department of Transportation (WSDOT) is completed reconstruction of the Evergreen Point (SR 250) floating bridge spanning Lake Washington in April 2016. The bridge is the longest floating bridge in the world. Floating bridges are support by large, water-right concrete pontoons. The bridge was reconstructed to withstand that anticipated increase in wind loads from more frequent extreme storms and hurricanes. Stronger winds may result in bridge failure by breaking the drawspan, anchor cables, or pontoons.

The new bridge design has also addressed anticipated increases in traffic congestion by increasing the width of the lands and adding a transit/High Occupancy Vehicle (HOV) lane. Additionally, there will be a new 14-foot-wide bicycle and pedestrian path that connects to recreational trails, improving recreation and increasing diversity of transportation options for commuters. The new design include flexibility for the City to add on a light rail in the future, also supporting diverse transportation options.

Sources:
Washington State Department of Transportation. (n.d.). SR 520 bridge replacement and HOV program – floating bridge facts. Retrieved from https://www.wsdot.wa.gov/Projects/SR520Bridge/About/BridgeFacts.htm.