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.

Completed improvements

  • Extended the "exit only" striping on the eastbound I-90 approach to the SR 18 exit. 

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.


  • 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.