SR 99 - Duwamish River Bridges - Special Bridge Repair

Project news

  • Construction is underway and no further lane closures are expected.
  • Hydraulic maintenance will continue through the summer.
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State Route 99 is one of the major highways 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 spring 2020, 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 2020: Construction is scheduled to begin.
  • Fall 2020: Construction is scheduled to be complete.


Financial Data for PIN 109926T
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $2,558
Pre-Existing Funds (PEF) $0
CWA $0
Total $2,558


Jordan Longacre
WSDOT Communications


SR 99 Duwamish River Bridge project map