A new westbound Interstate 90 on-ramp near Snoqualmie opened Thursday afternoon.
Washington State Department of Transportation (WSDOT) officials hope the ramp helps relieve traffic congestion and flow on Snoqualmie Parkway, which the agency says sees frequent back-ups during peak travel times.
The new on-ramp includes a dedicated lane for left-turners from eastbound SR 18 and a dedicated lane for right-turners from southbound Snoqualmie Parkway. Right-turners can take a free right turn without a traffic signal. WSDOT retimed the left-turn signal to give those cars a longer green light.
WSDOT also added ramp meters onto I-90, which will operate during peak travel times and will activate automatically based on traffic flow on the freeway. Metered signals aim to relieve congestion on I-90 by providing consistent gaps between merging vehicles.
Crews will finish the final paving and striping work in spring 2020 when the weather improves.
The new ramp is part of WSDOT’s larger I-90/State Route 18 interchange project, which is expected to be completed in 2023. Contractor crews will construct the state’s second diverging diamond interchange, where traffic swaps sides of the road to allow through traffic and left turns to happen simultaneously. The goal is to cut down on the number of crashes by reducing conflict points.
The project will also widen nearly 1.5 miles of SR 18 to four lanes from the interchange to Deep Creek.
The state’s first diverging diamond interchange will be built at the Interstate 5/Marvin Road interchange in Lacey.