I-405 will see overnight closures from milepost 12 to Coal Creek Parkway Southeast on Thursday night, Sept. 3 through Friday morning, Sept. 4. I-5 will have single-lane reductions nightly near Alger/Lake Samish Road (exit 240) from Aug. 31 through Sept. 4, and northbound I-5 will have left lane closures nightly near North Lake Samish (exit 246) through Sept. 4.
WSDOT notes the I-5 fish passage construction projects will require alternating traffic on SR 20 from Swin Slough Bridge to Laconner Whitney Road/Bay View Road, with work continuing daily except weekends through further notice. SR 4 will have weekday closures between 50th and 42nd Avenues from 7:30 a.m. to 5 p.m. through Sept. 11.