I-90/Front Street Interchange Justification Report

I-90 Front Street Interchange Justification Report map


  • WSDOT and partners selected BergerABAM to develop an Interchange Justification Report.
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The Washington State Legislature allocated funding in 2017 for WSDOT to study potential improvements to the I-90/Front Street interchange area in Issaquah. WSDOT will form a project support team with the city of Issaquah and other local partners to define needs and provide input on the study.

 Why is WSDOT studying the I-90, Front Street interchange?

Commercial and residential development, as well as the population, in Issaquah and surrounding areas of King County are expected to grow substantially by 2040.  This will add more traffic to the I-90/Front Street interchange, a key access point for local residents and commuters.  The interchange already experiences severe congestion during peak commute times, which has significant effects on both mainline I-90 as well as Issaquah’s surface streets.

The End Result

The final study will help the community and Legislature plan and decide about future projects and funding to improve the I-90/Front Street interchange.

Study benefits

  • Stakeholders: Representatives from local jurisdictions and agencies will provide feedback and direction about potential intersection improvements that reflect the area’s needs and coordinates with the local road projects.  
  • Informs future decisions: WSDOT will provide this study to the legislature as a tool to help it make decisions about the future of the interchange.

What is the study timeline?

Late 2017: WSDOT will form Project Support Team to assist in development of potential future improvements.
Mid 2018: Analysis of potential design options.
Late 2018/early 2019: Select preferred alternative.
Mid 2019: Final study delivered to the Legislature.

Financial Information

The Legislature allocated $2.3 million in the 2017-2019 biennium for this study through the 2015 Connecting Washington funding package. 

How can I get more information?

Adam Emerson
Project Manager
(206) 440-4279

Kris Olsen
(206) 440-4704