SR 99 - Duwamish River Bridges - Special Bridge Repair - Complete October 2020


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.

In the spring of 2020, contractor crews made mechanical and electrical repairs to the northbound and southbound SR 99 Duwamish River Bridges. This work was 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 advertised for competitive bidding.
  • April 2019: Project awarded to Kraemer North America, LLC.
  • Spring 2020: Construction scheduled to begin.
  • Fall 2020: Construction scheduled to be complete.


Funding came from state funds for bridge and structures preservation with a final cost of $2,019,128.63.


Jordan Longacre
WSDOT Communications


SR 99 Duwamish River Bridge project map