WSDOT is warning drivers to plan ahead for another busy weekend of highway construction across Puget Sound.
The Washington State Department of Transportation (WSDOT) is warning drivers to plan for a busy weekend of highway construction across Puget Sound.
The closures will run from Friday, Aug. 21, through Monday, Aug. 24.
Travelers should expect congestion and delays on Interstate 405, Interstate 5, State Route 520 and State Route 99, with major closures in Bellevue, Seattle and Renton, WSDOT said.
The biggest impacts include a full closure of southbound I-405 from Bellevue to Renton, a full closure of the SR 520 and Montlake Boulevard interchange, and closures on portions of SR 99 in Seattle.
Northbound I-5 will also remain reduced to two lanes across the Ship Canal Bridge.
I-405
Southbound I-405 will close from Coal Creek Parkway Southeast to North 30th Street from 11:30 p.m. Friday, Aug. 21, to 4 a.m. Monday, Aug. 24.
That closure will affect several on- and off-ramps, including:
- Coal Creek Parkway Southeast on-ramp to southbound I-405
- Lake Washington Boulevard ramps at Exit 9
- Northeast 44th Street ramps at Exit 7
- Southbound I-405 off-ramp to Northeast 30th Street at Exit 6
WSDOT said crews will be working on drainage, repaving and a traffic switch as part of the I-405 Renton to Bellevue Widening and Express Toll Lanes Project. A southbound detour will be posted.
Montlake, SR 520 ramps
In Seattle, Montlake Boulevard will close between East Hamlin Street and East Louisa Street from 10 p.m. Friday, Aug. 21, to 6 a.m. Monday, Aug. 24, for work on the SR 520 interchange.
The closure will shut down the Montlake Boulevard on-ramps to eastbound and westbound SR 520, as well as the eastbound SR 520 off-ramp to Montlake Boulevard. Other closures will include part of East Roanoke Street and Lake Washington Boulevard near the interchange.
The westbound SR 520 off-ramp to northbound Montlake Boulevard will remain open, and WSDOT said it will maintain a path for people walking, biking and rolling across the freeway.
SR 99
Farther south, northbound SR 99 will close at the First Avenue South Bridge from 5 a.m. Saturday, Aug. 22, through 11:59 p.m. Sunday, Aug. 23, for bridge and structure preservation work.
During that closure, drivers will not be able to access East Marginal Way or Michigan Street from the First Avenue South Bridge or continue north on SR 99. Additional closures will affect connections from Occidental Avenue South and South Kenyon Street, West Marginal Way South and South Holden Street, and First Avenue South to northbound SR 509.
Revive I-5 continues on northbound I-5
Northbound I-5 in Seattle remains reduced to two lanes across the Ship Canal Bridge through the end of 2026 as part of the Revive I-5 Ship Canal Bridge Preservation project. The Harvard Avenue on-ramp to northbound I-5 is closed until mid-October.
WSDOT said travelers should allow extra time, check traffic conditions before leaving, and use transit when possible.
Work may be rescheduled if weather changes.
