Agate Pass Bridge will be closed to one lane from Feb. 12-15 and Feb. 20-March 2 so work crews can give the span its annual cleaning.
Drivers heading across the bridge during daylight hours can expect 30-minute delays, according to the Washington State Department of Transportation.
Crews will clean and low-pressure wash the bridge, plus do other maintenance on the 67-year-old bridge.
Drivers are being advised to add time for travel across the bridge, and are also being asked to minimize discretionary trips and avoid the bridge during work hours, if possible.
The bridge will be reduced to one alternating lane of traffic during the following times:
8:45 to 3 p.m. Monday through Thursday, Feb. 12-15;
8:45 a.m. to 3 p.m. weekdays from Tuesday, Feb. 20 through Friday, March 2; and
7:45 a.m. to 2 p.m. Saturday, Feb. 24 and Sunday, Feb. 25.
State transportation crews clean roughly 30 bridges every year, including the Agate Passage Bridge on Highway 305, which was built in 1950.
Work during daytime hours is necessary, officials said, because space is limited on the structure and Under Bridge Inspection Trucks must be safely maneuvered across and under the bridge.