Traffic alert: WSDOT postpones 5-day closure, some weekend work due to weather
May 15, 2025, 5:00 AM | Updated: 3:24 pm
WSDOT is rolling out major shutdowns, including reducing lanes on I-405 south for the I-405/Renton to Bellevue Widening and Express Toll Lanes Project. (Image courtesy of WSDOT)
(Image courtesy of WSDOT)
Drivers will want to plan ahead as the Washington State Department of Transportation (WSDOT) is rolling out several closures over the weekend and spilling into next week. However, WSDOT announced some closures have been postponed due to weather.
State Route 18 closure at I-90 postponed
Drivers along State Route 18 (SR 18) at I-90 will see big changes following a 5-day closure at this busy interchange near the city of Snoqualmie. The Washington State Department of Transportation (WSDOT) decided on this unprecedented closure to tackle a number of projects at once, as opposed to taking a series of weekend closures to address the next phase of the I-90/SR18 – Diverging Diamond Interchange Project sometime after Memorial Day.
Crews will install new drainage and electrical crossings, pave the new roadway, and construct concrete islands to form the southern part of the new I-90/SR 18 diverging diamond interchange.
However, work on the left turn pocket for traffic from westbound SR 18 onto Southeast 104th Street, as well as the signalized U-turn south of I-90 (which will allow eastbound SR 18 traffic to head westbound toward Auburn), has been postponed for rain. Both of these features will be operational when SR 18 reopens on Wednesday, May 21.
During the closure, there will be no access on SR 18 underneath the I-90 overpass. Drivers will be able to access Snoqualmie Parkway from westbound I-90 only, and accessing SR 18 will only be open from eastbound I-90. Detours will be in place.
This extended closure starts Thursday, May 15 at 9 p.m. to Wednesday, May 21 at 5 a.m.
Lane and ramp closures on I-405 in Renton postponed
The one-lane reduction on southbound I-405 has also been delayed due to weather. Eventually, crews will close one lane between Northeast 44th Street and Northeast 30th Street while they work to realign and repave the Northeast 30th Street on, and off-ramps. This work will fully close the on-ramp to southbound I-405 and the off-ramp from southbound I-405 at Northeast 30th Street.
Closures begin Friday at 11 p.m. to Monday, May 19, at 4 a.m. Detours will be in place. Drivers should expect heavy delays through Renton, with added freight traffic due to the closure at the SR 18 and I-90 interchange.
State Route 529 closures on the Snohomish River Bridge
Unlike the past couple of weekends, there will be 12-hour closures on Saturday and Sunday on northbound State Route 529 (SR 529) for bridge maintenance, including repair to bridge girders. This work will not affect southbound SR 529. Daily closures are scheduled between 6 a.m. to 6 p.m.
Westbound I-90 closure between Mercer Island and Seattle
All westbound lanes on I-90 will close between Island Crest Way on Mercer Island to Rainier Avenue South in Seattle for routine maintenance inside the Mercer Tunnel and the Mount Baker Tunnel. Routine maintenance typically includes fire suppression testing, testing emergency systems, replacing bulbs, and overall cleaning.
Westbound I-90 lanes will begin closing Friday, May 16, at 8:30 p.m., with all lanes closed by 10 p.m. All ramps along this route will also close, with all lanes and ramps reopened by 6 a.m., Saturday, May 17. This leaves westbound SR 520 as the only route across Lake Washington during this closure.
Northeast 85th Street closure at I-405 in Kirkland
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Both directions of Northeast 85th Street will fully close between Kirkland and Totem Lake to allow WSDOT crews to perform a number of big projects, including demolishing the old bridges and noise walls, repaving ramps, and installing new gas lines and a waterline.
The closure—between 114th Avenue Northeast (Kirkland) and 120th Avenue Northeast (Totem Lake)—begins Friday, May 16, at 11 p.m. to Monday, May 19, at 5 a.m.
Click here to see the detours this weekend.
