I-90 - SR 18 Interchange Improvements - Low-cost improvements - What's being done now

WSDOT has kept a close eye on this interchange for several years. When possible, low-cost improvements have been implemented to enhance safety and keep vehicles moving as efficiently as possible as more people move to Snoqualmie Ridge.

Upcoming improvements

  • Spring/summer 2019: Extend the "exit only" striping on the eastbound I-90 approach to the SR 18 exit. The new striping will extend slightly more than one mile back from the exit. This work was originally planned to occur in 2018, but it has been added to a paving project at no additional cost.

A map showing the location of new exit-striping and new electronic congestion warning signs on I-90 approaching the SR 18 interchange near Snoqualmie, WA.

Completed improvements

  • Installed two new active warning signs on eastbound I-90 to notify travelers of stopped traffic ahead. The first sign is approximately two miles before the I-90/SR 18 interchange, and the second sign is about a mile before the interchange.
  • Widened the eastbound I-90 off-ramp to SR 18. 
  • Changed the right lanes of eastbound and westbound I-90 to exit-only lanes.
  • Partnered with the city of Snoqualmie to change the lane configuration on southbound Snoqualmie Parkway - making the southbound right lane a right-turn-only lane to the I-90 westbound on-ramp.
  • Adjusted traffic signal timing at the two signalized intersections to operate the interchange as efficiently as possible.
  • Installed “Thru traffic keep left” signs on both directions of I-90 prior to the SR 18 interchange to guide through-traffic to stay in the left two lanes and keep the right lanes clear for drivers exiting to SR 18 or Snoqualmie Parkway.
  • Installed “No U-turn” signs on SR 18 at the interchange to prohibit U-turns that have caused congestion for the off-ramp traffic.