I-90 / SR 18 Interchange Improvements

The Interstate 90 / State Route 18 interchange is a problematic transportation challenge for Snoqualmie. After many years of meetings with the Washington State Department of Transportation (WSDOT) and local leadership testimony in Olympia,  the Washington State Legislature approved $150 million to improve travel times and safety performance at the interchange.

Funding to design and construct interchange improvements was moved up by six years from 2029 to 2023 during the 2017 legislative session. 

News Release: Warning Signals Installed on Eastbound I-90 Approaching Exit 25 (05/13/19)

News Release: Snoqualmie Tribe Donates $75K for Dedicated Lane at Interchange (04/02/19)

News Release: Dedicated Traffic Lane May Be Constructed from Snoqualmie Parkway onto Westbound I-90 (01/24/19)

News Release: City Implores WSDOT to Use Weigh Station as Dedicated On-Ramp (10/24/18)


2017: Design work initiated
2018-2019: Community engagement, environmental and traffic analysis
2021: Construction tentatively scheduled to begin
2023: New interchange opens (anticipated)


  • Improved traffic flow and congestion relief
  • Increased safety 
  • Improved travel and commute times on I-90, SR 18, and Snoqualmie Parkway
  • Reduced freight traffic on local city streets by relocating the weigh station

More Information

Visit the
 WSDOT website for detailed information about this project.
  1. Mark Hofman

    Community Development Director
    Phone: 425-888-8007