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

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WSDOT contractor crews from Gary Merlino Construction Co. Inc. completed the following work on northbound I-5 between South 260th Street in Des Moines and the Duwamish River Bridge in Tukwila:

  • Ground off the ruts and bumps in all lanes.
  • Replaced approximately 440 broken concrete panels.
  • Resurfaced a four-mile stretch between SR 516 and South 170th Street using a crack, seat and overlay method. Then repaved all lanes with new asphalt.
  • Replaced eight expansion joints on the Interurban Avenue and Duwamish River bridges.
  • Rehabilitated the Interurban Avenue and Duwamish River bridge decks.
  • Created better sidewalk connections for people of all abilities at several intersections.

This section of northbound I-5 was built in 1965 and was designed to last about 25 year, but it lasted more than 50 years before major rehabilitation was needed. Cracks and ruts had developed in the lanes that now carry approximately 100,000 vehicles each day, and the worn out expansion joints needed to be replaced. 

This project is part of a multi-year effort to preserve I-5 through King County.

How you benefit

  • Safety:
    • Eliminating ruts and cracks in the pavement lessens the opportunity for water to collect on the roadway, which can reduce traction for vehicles.
    • Replacing expansion joints on the Interurban Avenue and Duwamish River bridges reduces the chances that an aging expansion joint will fail, which could be hazardous to travelers.
  • Preservation/Economic:
    • Repairing broken concrete panels, repaving and replacing expansion joints improves the driving surface and reduces the need for costly emergency repairs.
    • Replacing expansion joints on the Interurban Avenue and Duwamish River bridges preserves the infrastructure for years to come.
    • Repaving the interstate with asphalt is less expensive and disruptive than replacing all four-miles of concrete panels.


  • November 2016: Project was advertised for competitive bidding.
  • January 2017: Project was awarded to Gary Merlino Construction Co. Inc.
  • April 2017: Construction began.
  • Summer 2019: Construction complete.
  • Fall 2019 : Emergency expansion joint repair


Financial Data for PIN 100506G, 100506H
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $34,464
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $3,802
CWA $0
Total $38,266


Tom Pearce
WSDOT Communications