Expect Delays at the I-90/SR 18 Interchange Aug. 21-28 for Ramp Closures and Traffic Shift

People who use the Interstate 90/State Route 18 interchange should add travel time next week for two nights of SR 18 lane reductions Aug. 21-22, and several days of eastbound I-90 on-ramp closures, Aug. 22 and 25-28.

Shifting SR 18 traffic west
Construction crews working for the Washington State Department of Transportation (WSDOT) are finished building the west half of Lake Creek bridge just south of the interchange. To complete the other half, workers will shift traffic overnight to the west side.

From 9 p.m. to 5 a.m. Monday and Tuesday nights, Aug. 21-22, flaggers will alternate traffic through a single lane while workers move temporary concrete barriers into the new traffic configuration.

Eastbound I-90 on-ramp closures
Related to Lake Creek bridge work, crews will close the SR 18 ramp to eastbound I-90 for culvert installation:

  • From 9 p.m. Tuesday, Aug. 22, to 5 a.m. Wednesday, Aug. 23.
  • Round the clock from 9 p.m. Friday, Aug. 25, through 5 a.m. Monday, Aug. 28.

To head east, people can go westbound on I-90 and take the Preston/Fall City exit (Exit 22), then get onto eastbound I-90 from there.

Improving traffic flow and safety
The four-lane bridge over Lake Creek is the first of three bridges being built to widen SR 18 between I-90 and the Tiger Mountain summit. When this project is complete in early 2025, a second project will finish widening SR 18 to Issaquah-Hobart Road.

Real-time traffic information is available on the WSDOT app and on the regionwide travel map.

[Information provided by the Washington State Department of Transportation]

Comments are closed.


  • does anyone know if the 4 lane highway 18 from i90 to before raging river will open earlier than the rest of the project? it seems to be on schedule for doing that and it would be a significant improvement for traffic congestion and safety.

    1. Yes, SR 18 widening between I-90 and Deep Creek and the new diverging diamond interchange should open by fall 2024. The entire project should be complete by early 2025.

  • Living Snoqualmie