New westbound I-90 auxiliary ramp in Snoqualmie scheduled to open on Thursday, Dec. 5

Final paving, striping to occur in spring 2020

By Nicole Daniels

After about a month of work, the new temporary State Route 18/Snoqualmie Parkway auxiliary on-ramp to westbound Interstate 90 is scheduled to open to traffic Thursday afternoon, Dec. 5, as long as the weather stays dry. These modifications are expected to provide some short-term congestion relief and help improve traffic flow on Snoqualmie Parkway and nearby local intersections before the new I-90/SR 18 interchange project is complete in 2023.

Completed improvements
In partnership with the city of Snoqualmie, our contractor crews from Road Construction Northwest, Inc. used the old westbound I-90 weigh station property to create a second on-ramp lane for highway users. The traffic signal on SR 18 was also retimed, and ramp meters were added to evenly distribute vehicles merging onto westbound I-90.

Graphic outlining the changes to the Snoqualmie Parkway/SR 18 on-ramp to westbound I-90

Southbound Snoqualmie Parkway travelers going to westbound I-90 will notice:

• A right turn only lane on southbound Snoqualmie Parkway.
• No traffic signal as you enter the ramp.
• A dedicated westbound I-90 on-ramp lane.
• A meter at the end of the on-ramp.

Eastbound SR 18 travelers going to westbound I-90 will notice:

• A retimed traffic signal on SR 18 - providing a longer green light for those turning on to westbound I-90.
• A dedicated westbound I-90 on-ramp lane.
• A meter at the end of the on-ramp.

Why meter the on-ramp?
The ramp meters will operate during peak commute times - activating automatically based on westbound I-90 traffic flow. Metering the two-lane on-ramp will reduce congestion on westbound I-90 by providing consistent gaps between vehicles, rather than allowing multiple vehicles to flood the highway at once.

Final work resumes in spring 2020
The final paving and striping will occur in spring 2020 - when warmer, drier weather returns. Crews will complete this weather-dependent work during daytime lane closures. Travelers should check the King County construction page or sign up for weekly email updates for current closure information.