Expect overnight delays on I-90 near Snoqualmie during multi-lane closures and gradual slowdowns

Motorists traveling east and west on Interstate 90 near Snoqualmie should prepare for overnight delays Monday, June 3 through Friday, June 7.

Delays will occur as crews install support structures for the new overhead signs near the State Route 18 interchange. These new signs are part of the I-90/SR 18 intersection improvement project , which aims to ease traffic flow through a new diverging diamond interchange.

Details of lane closures and traffic slowdowns

Drivers should expect the closure of both left lanes of eastbound and westbound I-90, accompanied by gradual slowdowns as contractor crews working for the Washington State Department of Transportation (WSDOT) ) are putting in place the new support structures, known as signal bridges. I-90.

Schedule of lane closures and traffic delays on I-90

From Monday June 3 to Tuesday morning June 4:

• 9:00 p.m. to 5:00 a.m.: Both left lanes of I-90 westbound will close near SR 18.

From Tuesday June 4 to Wednesday morning June 5:

• 9:00 p.m. to 5:00 a.m.: Both left lanes of eastbound and westbound I-90 will close near SR 18.
• 11:59 p.m. to 4:00 a.m.: Intermittent rolling slowdowns on westbound I-90 from the 468th Avenue Southeast interchange (exit 34).

From Wednesday June 5 to Thursday morning June 6:

• 9:00 p.m. to 5:00 a.m.: Both left lanes of I-90 eastbound will close near SR 18.
• 11:59 p.m. to 4:00 a.m.: Intermittent rolling slowdowns on eastbound I-90 from the East Sunset Way/Highland Drive Northeast interchange (exit 18).

From Thursday June 6 to Friday morning June 7:

• 9:00 p.m. to 5:00 a.m.: Both left lanes of eastbound and westbound I-90 will close near SR 18.

During these rolling slowdowns, traffic control vehicles and the Washington State Patrol will guide drivers through the work zone at reduced speeds, allowing crews to safely raise and secure the traffic bridges above the I-90 lanes.

Diverging Diamond Interchange to Improve Traffic Flow

The new diverging diamond interchange, identified by WSDOT in 2016 as the optimal solution to improve the efficiency and safety of the I-90/SR 18 interchange, is expected to be completed in late 2024.

It will be the second such interchange in Washington state, designed to allow through traffic and left turns simultaneously, ensuring traffic flows smoothly.

In addition to the interchange, the $188 million project will widen approximately two miles of SR 18 south of I-90 to two lanes in each direction, improving traffic flow and safety.

Stay informed with real-time travel updates

For real-time travel information, motorists can use the WSDOT mobile app, view the WSDOT Travel Center map, or sign up for email updates from WSDOT.

Travelers are encouraged to remain vigilant and allow extra travel time during these nighttime construction activities. WSDOT appreciates the public's patience and cooperation as it works to improve highway infrastructure.