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I-5 - NB S 260th St to Duwamish River Br - Concrete Pavement Rehab and ADA


June 2017

  • Northbound I-5 will be reduced to two lanes from SR 516 in SeaTac to South 170th Street in Tukwila from 8 p.m. Friday, June 23, to 5 a.m. Monday, June 26. See "Project details" below for other scheduled weekend-long lane reductions.
  • Drivers should be prepared for nighttime lane closures between 8 p.m. and 5 a.m.
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Why is WSDOT rehabilitating this section of northbound I-5?
This section of I-5 was built in 1965 and designed to last about 25 years. It has now lasted 51 years. It carries about 100,000 vehicles each day. Much of the roadway is worn out, and drivers often notice bumps where concrete panels are broken. Decades of heavy traffic has worn ruts into the roadway. In addition, eight expansion joints are worn out and must be replaced.
Project details
Contractor crews are rehabilitating northbound I-5 from South 260th Street to the Duwamish River Bridge. Drivers should be prepared for most of the work to be done during overnight lane reductions as well as 10 weekend-long lane reductions. Two weekends are complete. Four more weekends are scheduled for paving between SR 516 in SeaTac and South 170th Street in Tukwila, beginning at 8 p.m. Friday and ending by 5 a.m. Monday:

  • June 23-26
  • July 7-10 and 14-17
  • Aug. 11-14

Two more weekend-long lane reductions will be scheduled to replace expansion joints on northbound I-5 at the Duwamish River in late summer/fall 2017. The final two will be to replace expansion joints on northbound I-5 at Interurban Avenue in the first half of 2018.

This two-year project presents numerous challenges as crews will: 

  • Replace about 440 broken concrete panels. 
  • Repave about 4 miles of all lanes with asphalt between SR 516 and South 178th Street. 
  • Grind off ruts and bumps. 
  • Replace eight expansion joints on the Interurban Avenue and Duwamish River bridges. 
  • Rehabilitate the Interurban Avenue and Duwamish River bridge decks.
  • Make ADA improvements at several intersections. 

The End Result
This preservation and improvement project will create safer and improved driving conditions for the tens of thousands of travelers who rely on it daily. It also will extend the useful life of I-5 for decades to come. This project is part of a years-long effort to preserve I-5 through King County.

Project Benefits

  • Replacing broken concrete panels, repaving and grinding the interstate improves the driving surface and will extend the life of I-5. 
  • Replacing expansion joints on the Interurban Avenue and Duwamish River bridges ensures those structures will remain open and operational.
  • Improving the interstate surface eliminates potholes and will help prevent future potholes and cracks. Eliminating the wheel ruts improves traction and will create a smoother, safer ride for drivers. 
  • Replacing the expansion joints on the Interurban Avenue and Duwamish River bridges reduces the chances that an aging expansion joint could fail, which would create a hazard for drivers and cause an emergency closure on I-5.


  • Replacing broken concrete panels, repaving and replacing expansion joints during a scheduled project reduces the need for emergency repairs. These are more expensive than scheduled repairs and cause additional congestion, particularly during peak commute hours. 
  • Repaving a 4-mile section of the interstate with asphalt instead of concrete is less expensive and less disruptive than replacing all of the concrete panels.

What is the project timeline?
November 2016: Project will be advertised for competitive bidding.
January 2017: Project awarded to Gary Merlino Construction Co. Inc.
April 2017: Work began.
June 23-26, 2017: Third of six weekend-long lane reductions begins.
Late 2018: Work will be complete.

Financial Information

Financial Data for PIN 100506G, 100506H
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $30,921
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $102
CWA $0
Total $31,023

How can I get more information?
Tom Pearce
WSDOT Communications
Phone: 206-440-4696

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