Thanks to outreach from the City of Snoqualmie and engaged residents, the Washington State Department of Transportation (WSDOT) has identified immediate, temporary fixes to address traffic congestion and safety concerns at the eastbound I-90 off-ramp to the new SR 18 diverging diamond interchange.
Following a Thursday afternoon meeting with the City and project partners, WSDOT confirmed that several short-term solutions will be implemented as soon as possible to ease backups on Exit 25. These measures are intended to improve conditions until the expanded lanes of SR 18 between the interchange and Deep Creek open later this year.
Mitigation measures include:
- Installation of plastic pylons (or “candlesticks”) to divide traffic between drivers heading toward SR 18 and those turning onto Snoqualmie Parkway.
- Placement of portable electronic signage on I-90 eastbound to guide drivers intending to use westbound SR 18 into the correct right-hand exit lane.
- Re-striping the off-ramp to organize traffic flow better. This option will require an overnight closure and may take longer to implement than signage or pylons.
Mayor Ross is also working with the Washington State Patrol, King County Councilmember Sarah Perry, and state legislators to ensure that public safety at the interchange remains a top priority.
“The entire project team has been responsive and receptive to our outreach, communications, and ideas,” the City stated in an update. “We thank our residents who assisted with this community team effort!”
According to WSDOT construction communicator David Rasbach, engineers have been monitoring the ramp and are collaborating with contractors on feasible actions to mitigate the congestion. “We expect the long queues to diminish once we finish widening SR 18 to two lanes in each direction later this fall,” Rasbach said.
In the meantime, WSDOT is encouraging drivers to follow signage, obey traffic laws, and exercise patience, particularly during high-volume travel periods like evening commutes and Sunday afternoons. Rasbach added that traffic diversion through downtown Snoqualmie should ease as ramp flow improves and that emergency access to northbound Snoqualmie Parkway is expected to benefit from the near-term changes.
The diverging diamond interchange was only the first phase of a larger I-90/SR 18 Interchange Improvements Project. Once the full SR 18 widening is complete—expected in late summer or early fall—vehicles traveling westbound will no longer be reduced to one lane south of I-90. The added capacity will work in tandem with the new interchange design to improve overall traffic conditions in the area.
For more information on the I-90/SR 18 Interchange Improvements Project, visit:
https://wsdot.wa.gov/construction-planning/search-projects/i-90-sr-18-interchange-improvements
Comments
Unless the pylons are closer than 6 feet apart, 18’ers will still come to a dead stop, block traffic, and try to squeeze in. Heck, I’m sure plenty will just drive right over them anyway.
All which was ever needed to make this a safe interchange is a 1/2 mile solid divider separating off the lane which goes to 18. That’s it. Just a simple divider. Not a $200 million dollar mess of spaghetti roads which fly in the face of over 100 years of traffic flow precedent in the US.
I bet if I searched through the proposals and debates for this monstrosity, I’d probably find that it was approved because normal interchanges are “racist” or some other marxist nonsense.
The real benefit comes when they get 2 lanes of traffic from from I-90 to Hobart. Right now the benefit is for the people turning left off the 18/Parkway on to 90. The next step is 2 lane traffic from 90 to Tiger Mt summit. After that 2 lane traffic to Hobart is the final solution. The temporary fix to discourage lane crashers may or may not help but I think the total package is a net benefit unless you want to go down the road of flyovers for the interchanges.