BAINBRIDGE ISLAND — Delays are expected on the Agate Pass bridge through the end of the month, affecting North Olympic Peninsula drivers en route to the Bainbridge Island ferry terminal.

The state Highway 503 bridge, which connects Bainbridge Island to the Kitsap County mainland, is being deep-cleaned.

Traffic will be reduced to one lane during the day through Feb. 28, state Department of Transportation officials said.

Drivers are advised to expect long traffic delays while crews hand-clean and low-pressure-wash the bridge’s chords and areas under the deck.

Single-lane alternating traffic will be in effect at the bridge between 8:45 a.m. and 3 p.m. on weekdays and from 7:45 a.m. and 3 p.m. on weekends.

On Friday, crews will stop work at 2:45 p.m. to accommodate Presidents Day ferry traffic.

Bicycle and pedestrian traffic will be escorted across the bridge during work hours.

The maintenance project began Monday.

“We know that daytime closures will cause traffic delays, and we wouldn’t be doing the work this way unless we thought it was absolutely necessary,” agency Assistant Region Administrator Troy Cowan said in a January news release.

“We want to make sure that nothing, not the crews, the equipment, the driving public or the bridge, are damaged in this process,” he added.

“We’re doing everything we can to work safely and efficiently, including working seven days a week and having multiple crews working above and below the bridge every day.”

The bridge was last cleaned before it was painted in 1991.

The 1,020-foot-long span is used by about 22,000 vehicles per day, officials said.