Directional closures set for I-405, SR 18 April 24–27

Eastbound SR 18 closure at Issaquah-Hobart Road begins April 23 ahead of weekend work

SEATTLE - With closures on two busy corridors looming, Seattle-area travelers should prepare for increased weekend congestion. A closure on Interstate 405 will begin late Friday, April 24. A second closure to continue improvements on the State Route 18/I-90 interchange will begin on Thursday night. Closures will continue through the weekend.

Contractor crews working for the Washington State Department of Transportation will close southbound I-405 in Renton and eastbound SR 18 between Issaquah-Hobart Road and the I-90/SR 18 interchange in Snoqualmie. Simultaneously, two northbound lanes on I-5 remain closed across the Ship Canal Bridge for major bridge repairs, adding to regional congestion.

Southbound I-405 closure

Crews will close southbound I-405 between SR 169 and SR 167 beginning as early as 11:59 p.m. Friday, April 24, and reopen it by 4 a.m. Monday, April 27. Travelers can follow a signed detour route.

During the closure, crews will install drainage, replace concrete pavement panels and pave the roadway as part of the I-405/Renton to Bellevue Widening and Express Toll Lanes project.

Eastbound SR 18 closure

Preparation work for an extended weekend closure of eastbound SR 18 began earlier in the week for the I-90 - SR 18 Interchange Improvements project. On Tuesday, April 21, crews closed one lane of eastbound SR 18 between Deep Creek and the I-90/SR 18 interchange while they removed approximately 8,500 feet of guardrail and concrete barriers. Eastbound SR 18 will be reduced to a single lane through Thursday, April 23.

The full closure of eastbound SR 18 for paving work is scheduled to begin as early as 9 p.m. Thursday, April 23. At least one lane of eastbound SR 18 is expected to reopen by 5 a.m. Monday, April 27, with additional work continuing in the eastbound right lane as crews reinstall guardrail, curbing and stormwater drains through Thursday, April 30.

Issaquah-Hobart Road and Issaquah city streets are not suitable for semi-trucks and freight traffic. During the eastbound SR 18 closures, freight traffic should use alternate routes or follow the signed detour on westbound SR 169 to northbound I-405, then take eastbound SR 900 to eastbound I-90.

What travelers should expect

• Delays and backups along alternate routes near Issaquah during the eastbound SR 18 closure.
• Longer backups on I-405 in both directions approaching Bellevue and heavier congestion throughout the I-405 corridor.
• Constrained travel in Seattle, where two northbound lanes of I-5 remain closed across the Ship Canal Bridge.

Plan ahead

When several major corridors are simultaneously limited, congestion can extend well beyond the construction areas as drivers shift to alternate routes. Travelers may encounter congestion in areas they typically do not associate with freeway construction, including local roads and parallel routes. Transit, park-and-ride options, flexible schedules and real-time travel information can make a meaningful difference during closures.

This work is weather-dependent and may be rescheduled. Schedule updates will be available on the project webpages, WSDOT's Travel Center map, the WSDOT mobile app and by signing up for King County email updates.