I-90 - Eastgate to SR 900 - Corridor Improvements

Project news

  • Construction is scheduled to begin in summer 2019.
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As population grows in the Puget Sound region, so does traffic congestion. In an effort to ease this congestion, contractor crews working for WSDOT will add capacity on I-90 between the Eastgate and West Lake Sammamish Parkway interchanges, by restriping the existing roadway and creating auxiliary lanes. These lanes will be located on the outside of the existing lanes in both directions of I-90, adding capacity and accessibility to all travelers 24 hours a day, seven days a week.

In addition, crews will also construct noise walls in strategic locations within the project area to minimize traffic noise impacts on local residents.

What's an auxiliary lane?
An auxiliary lane is a supplemental or extra lane between interchanges. They are frequently used between closely spaced interchanges to allow for maneuvering of entering and exiting traffic, speed changes, weaving and truck climbing.

Auxiliary lane diagram for the I-90 Eastgate to SR 900 Corridor Improvements project.


  • 2016 - 2019: Design phase.
  • March 2019: Project was advertised for competitive bidding.
  • May 2019: Project was awarded to Atkinson Construction, LLC.
  • Summer 2019: Construction is scheduled to begin.
  • Fall 2021: Construction is scheduled to be complete.


Financial Data for PIN 109052P
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $3,000
CWA $73,035
Total $76,035


Nicole Daniels
WSDOT Communications

Map for the I-90 Eastgate to SR 900 Corridor Improvements project.