SR 99 - Duwamish River Bridges - Special Bridge Repair

Project news

  • Construction is scheduled to begin in spring 2019. 
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State Route 99 is one of the major routes between downtown Seattle and the cities to the south, as well as Sea-Tac Airport. Carrying approximately 31,000 vehicles each day, with hundreds of boats passing under them monthly, the 1st Avenue South Bridges, formally known as the Duwamish River Bridges, are an important lifeline for residents and businesses.

Beginning in 2019, WSDOT contractor crews will make mechanical and electrical repairs to the northbound and southbound SR 99 Duwamish River Bridges. This work is essential, as the systems are responsible for opening and closing the bridge drawspans.

Needs & Benefits

  • Economic incentive/preservation: Repairing the mechanical and electrical systems on the bridges allows us to maintain the functionality of their drawspans and minimize unscheduled impacts to travelers and marine traffic. This also reduces the need for emergency repairs, which can be costly and cause increased congestion, especially during peak commute hours.


  • March 2019: Project was advertised for competitive bidding.
  • April 2019: Project was awarded to Kraemer North America, LLC.
  • Spring 2019: Construction is scheduled to begin.
  • Fall 2020: Construction is scheduled to be complete.


The total estimated cost for this project is $1.5 million.


Nicole Daniels
WSDOT Communications

SR 99 Duwamish River Bridge project map