I-90 Peak Use Shoulder Lanes


To ease congestion in the Interstate 90 corridor, the Washington State Department of Transportation (WSDOT), is creating added capacity between the Eastgate and Lakemont interchanges by adding auxiliary lanes.

These lanes will be located on the outside of the roadway in both directions of I-90, adding capacity 24 hours a day, seven days a week.

In addition, the project will construct new noise barriers in strategic locations to minimize impact on nearby residents, including those who live in South Lake Sammamish.

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.


  • 2016-2019: Design 
  • 2019-2021: Temporary I-90 traffic changes
  • July 27-October 2020: Eastbound lane closure of Northwest Sammamish Road: 
  • Summer 2021: Eastbound auxiliary lane opens
  • Fall 2022: Construction is scheduled to be complete.

City’s Role

The City of Issaquah is working closely with WSDOT during this project to minimize impact to local neighborhoods, and coordinate work schedules as the City improves local water/stormwater infrastructure north of I-90.

WSDOT’s project will also make room for the City to someday potentially add pedestrian/cyclist amenities in this area. Funding, however, is still needed, and likely years away. Learn more via this presentation.

Stay Connected

To stay connected on this this project, sign up for e-mail updates from WSDOT on their web page.