I-5 - SB Stillaguamish River Bridge - Painting

Project news

  • This project was awarded December 2020 to Southern Road & Bridge, LLC from Tarpon Springs, Florida.
  • Construction work began on April 12, 2021. 
  • Travelers can expect lane shifts and detours beginning Wednesday, June 23, 2021
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Needs & Benefits

The Stillaguamish River Bridge is in need of new paint to preserve and protect its aging structure. Existing paint on the southbound I-5 bridge is weathered and damaged, allowing corrosion to occur. This bridge preservation project will remove old peeling paint, clean exposed metal and apply new paint to the existing bridge structure on southbound I-5 under a full containment system. Minor maintenance and repairs will also be performed such as replacing joints and rivets.

Originally built in 1933, the Stillaguamish River Bridge carried two lanes in each direction of US 99.  When I-5 was built in the 1960s, the bridge became part of the freeway. Then, in 1971, a new bridge was built just east of the original bridge to carry three lanes of northbound I-5. The bridge deck was replaced in 2014 and this project will continue that important preservation work.

What travelers can expect

The southbound bridge will be closed and under full containment for the duration of this project. All southbound traffic will be diverted onto the existing median bypass on the adjacent northbound bridge for approximately 5 months.  

  • This will reduce northbound and southbound traffic from three lanes down to two lanes in each direction.
  • Travelers should anticipate increased congestion and backups during peak commute hours. 
  • Speed limits will be reduced from 70 mph to 55 mph through the work zone.


  • December 2020: Project advertised
  • Spring 2021: Construction begins
  • Fall 2021: Project completion


Federal funds will be used for this preservation project totaling approximately $2.6M.


Financial Data for PIN 100555U
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $7,837
CWA $0
Total $7,837


Meggan Carrigg Davidson

Location of the I-5 Stillaguamish River Bridge