Bellevue commuters who drive northbound I-405 between Renton and Coal Creek Parkway will lose the highway entirely this weekend.

The Washington State Department of Transportation is shutting down the stretch for roughly 52 hours as part of the $705 million Renton-to-Bellevue widening project.

The closure begins at 11:30 p.m. Friday, Aug. 7, and runs through 4 a.m. Monday, Aug. 10. A signed detour will route drivers off the highway between North Southport Drive/Northeast Sunset Boulevard and Coal Creek Parkway Southeast.

During the shutdown, crews will excavate drainage crossings, replace full sections of pavement and perform a traffic switch on northbound I-405, according to WSDOT's project page. The same segment saw a similar weekend closure in April.

Where to expect congestion

WSDOT warned in its Aug. 3 announcement that drivers should expect heavy backups on northbound I-405 approaching Renton, increased traffic on northbound I-5 (already reduced to two lanes across the Ship Canal Bridge through the end of 2026) and heavy congestion on surface streets in Kirkland.

The pain compounds. The I-405/Northeast 85th Street interchange ramps and NE 85th Street from Sixth Street to 120th Avenue NE in Kirkland also close at 10 p.m. Friday, Aug. 7, through 4 a.m. Monday, Aug. 10. Eastbound SR 520 between I-5 and Montlake Boulevard shuts down from 7 p.m. Saturday, Aug. 8, to 11 a.m. Sunday, Aug. 9, for expansion joint repair.

WSDOT warned travelers to expect longer and less predictable trips, with delays occurring in new places and at new times as construction work moves around the region.

What the project delivers

The I-405/Renton to Bellevue Widening and Express Toll Lanes Project, awarded to contractor Flatiron-Lane Joint Venture in October 2019 for $705 million, will add one lane in each direction and create a dual express toll lane system between SR 167 in Renton and Northeast Sixth Street in Bellevue.

The project also includes 2.5 miles of new paved Eastrail in Renton and Bellevue and a new direct-access ramp and transit station at NE 44th Street in Renton to support Sound Transit bus rapid transit.

Construction began in fall 2020 and was originally due to finish by the end of 2025. WSDOT said in a November 2025 blog post that it is now targeting summer 2027, citing contractor delays and active litigation with Flatiron-Lane over missed milestones and disputed payment claims.

The construction season resumed after a pause to accommodate FIFA World Cup matches in June and July.

How to plan

WSDOT urges drivers to use transit and park-and-ride lots, adjust travel times and check real-time conditions on the WSDOT Travel Center map or mobile app. Much of the work requires dry weather and could be rescheduled if it rains.

Residents can call WSDOT's 24-hour construction hotline at 425-818-0161 or subscribe to project updates at [email protected].