On Friday, May 19, 2017, the City of Snoqualmie released a YouTube video detailing improvement plans for the congested and dangerous I-90/SR 18 interchange. The design and planning stage of the improvement project should begin in July 2017.
The $150 million state transportation project originally wasn’t slated to be funded until 2023, but 5th District representatives were able to push the project up during the 2017 legislative session.
Snoqualmie Mayor Matt Larson explains the history of the 90/18 interchange improvement project, along with construction timeline in the recently released video.
WSDOT plans to use an uncommon traffic solution at the busy interchange called a Diverging Diamond Interchange (DDI), instead of an expensive flyover ramp. The realized savings will then be used to widen the SR 18 corridor between I-90 and Tiger Mountain in order to keep traffic from backing up on I-90, which currently occurs during peak commute hours.
You can find out more about what’s in store for the 90/18 interchange, including how DDI’s work, below: