Drivers across the Puget Sound region should plan ahead for a weekend of significant construction-related traffic delays, including a full closure of northbound Interstate 405 between Renton and Bellevue and lane restrictions on State Route 520 in Redmond.
The biggest impact will be a full closure of all northbound I-405 lanes between North Southport Drive in Renton and Coal Creek Parkway Southeast in Bellevue, beginning at 11:30 p.m. Friday and lasting until 4 a.m. Monday.
According to the Washington State Department of Transportation, crews will complete drainage work, paving, and a traffic shift as part of the I-405/Renton to Bellevue Widening and Express Toll Lanes Project.
Several ramps along the closure area will also be closed throughout the weekend, including:
- North Southport Drive on-ramp to northbound I-405
- North 30th Street on- and off-ramps (Exit 6)
- Northeast 44th Street on- and off-ramps (Exit 7)
- 112th Avenue Southeast on- and off-ramps (Exit 9)
- Northbound I-405 off-ramp to Coal Creek Parkway Southeast (Exit 10)
WSDOT has established a signed detour route. Drivers can use SR 900, Duvall Avenue, and Coal Creek Parkway Southeast to travel around the closure.
However, travelers should expect additional delays along the detour. WSDOT noted northbound lane reductions are already in place on Coal Creek Parkway Southeast because of King County’s Coal Creek Sewer Upgrade Project.
Further east, drivers using SR 520 through Redmond will encounter lane restrictions this weekend.
Bridge maintenance crews will close the two right lanes of eastbound SR 520 over Lake Sammamish Parkway from 5 a.m. to 1 p.m. Saturday and Sunday while repair work is underway.
No official detour is planned for the SR 520 work zone, but drivers should allow extra travel time, especially during daytime hours. Alternate routes, including 148th Avenue Northeast and Redmond Way, may help motorists avoid backups.
With multiple construction projects occurring simultaneously, transportation officials are urging drivers to check conditions before leaving, plan alternate routes, and give themselves additional time to reach their destinations.
The construction work comes as weekend travel remains busy across the region, increasing the likelihood of congestion around major closures and detour routes.