State Route 20 will alternate traffic with flaggers from Swin Slough Bridge to Laconner Whitney Road for Anacortes utilities work starting Aug. 21.
I-5 will have single-lane reductions nightly from 8 p.m. to 5 a.m. near Alger/Lake Samish Road (exit 240) through Sept. 10 for fish passage construction. Northbound I-5 will also lose a left lane nightly from Aug. 30 through Sept. 4 near North Lake Samish (exit 246).
SR 4 will have single-lane closures weekdays from 7:30 a.m. to 5 p.m. between 50th and 42nd Avenues through Sept. 11 for gas main work. SR 99 will close its right lane from Russell Way to Gibson Road on Aug. 31 through Sept. 1.