Local Information

88 years and counting: Southbound Stillaguamish River bridge to be fully stripped and repainted

Monday, April 5, 2021 - 10:46

Jordan Longacre, communications, (206) 440-4479

Interstate 5 travelers near Arlington should plan for traffic delays, lane reductions for approximately five months

ARLINGTON – Nearly a century after being built, the trusses of the southbound Stillaguamish River bridge near Arlington will be stripped to bare metal and get a new coat of paint this year to protect the aging structure for years to come.

Travelers using Interstate 5 in the area can expect traffic delays and lane reductions throughout the project and should plan accordingly.

On Monday, April 12, Washington State Department of Transportation contractor crews with Southern Road & Bridge, LLC, will begin preservation work on the bridge. Much more than just a matter of appearance, new paint helps prolong the life of the bridge.

Painting the bridge

Existing paint on the southbound I-5 bridge is weathered and damaged, allowing corrosion to occur. The bridge preservation project will remove old peeling paint, taking the entire bridge back to bare metal for the first time since construction.  Crews will clean exposed metal and apply new paint under a full containment system to protect the waterway below. Minor maintenance and repairs will also be performed, such as replacing joints and rivets as needed.

What travelers can expect

Beginning in June, all southbound traffic will be diverted onto the existing median bypass on the adjacent northbound bridge for approximately five months. This will keep both directions of I-5 flowing during the work.

  • Both directions, northbound and southbound I-5 will be reduced from three to two lanes in each direction 24/7.
  • The southbound bridge will be closed and under full containment.
  • Travelers should anticipate increased congestion and back-ups during peak commute hours. 
  • Once the work starts, speed limits will be reduced through the work area to 55 miles per hour, and the lanes will be reduced from 12 feet to 11 feet in width.

Stillaguamish River bridge                               

The southbound Stillaguamish River bridge was built in 1933 to carry US 99. The steel truss bridge comprises three spans over the river and spans 607 feet. When I-5 opened in the 1960s, the bridge became part of the interstate, carrying two lanes in each direction. A new northbound bridge opened in 1971 and traffic was separated, resulting in three lanes on each bridge.

Each span of the bridge carries an average of 39,000 vehicles per day, but that can rise to 50,000 per day during summer. The heaviest traffic volume occurs between 3 p.m. to 6 p.m. Thursdays and Fridays and from 11 a.m. to 4 p.m. on the weekends northbound, and from 4 p.m. to 6 p.m. Sundays southbound.

In the summer of 2014, WSDOT contractor crews replaced the southbound bridge deck, worn out after 81 years of use that caused cracks, ruts and potholes. It took about four months to complete the work and the bridge reopened in November 2014.

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