I-90 - SR 18 Interchange Improvements - SR 18 - Snoqualmie Parkway Ramp to I-90

Before the interchange improvement construction begins in 2021, we will modify the existing ramp from southbound Snoqualmie Parkway to westbound I-90. This auxiliary ramp will provide some congestion relief and improve traffic flow before the new interchange opens in 2023.

We will modify the existing ramp by using the decommissioned weigh and inspection station. Drivers can expect the following changes:

  • Southbound Snoqualmie Parkway to westbound I-90 drivers will have a dedicated right turn lane with no traffic signal as they turn onto the ramp.
  • The southbound to westbound drivers will have their own dedicated ramp lane.
  • Eastbound SR 18 drivers turning west onto I-90 will have their own dedicated ramp lane.
  • The traffic signal for SR 18 to westbound I-90 will be retimed to provide a longer green light for drivers.
  • Traffic meters will be installed for both ramps just before the ramps merge.

We anticipate the additional ramp lane and the retimed signal will result in shorter backups and improved traffic flow through the intersection.

This map shows the new dedicated right turn lane from southbound Snoqualmie Parkway and a new dedicated ramp lane to westbound I-90 near Snoqualmie, Washington that will be built in the fall and winter of 2019.

View a larger version of the modified ramp on the WSDOT Flickr site.

Road Construction Northwest, Inc. of Renton begins construction in October with ramp open to drivers by the end of the year. The work is jointly funded by WSDOT, the cities of Snoqualmie, Covington, Maple Valley and the Snoqualmie Tribe. An additional modification to the on-ramps to connect them to the new I-90/SR 18 interchange will occur before the new interchange opens in 2023.