Residents and visitors traveling across Penobscot Narrows Bridge should plan for delays as the state later this month begins paving and other improvements on the structure.

Starting April 24 and running until the end of the month, a shoulder on the bridge will be closed as a crew begins preparing for paving and waterproofing work, Ted Talbot, Maine Department of Transportation spokesman, said.

Then, starting May 1 and lasting until May 19, the bridge will be reduced to one lane of alternating traffic, Talbot said. Flaggers will be posted at the bridge to direct vehicles.

Once the bridge is reopened to two lanes, work will occur only at night. Weather permitting, the work should be completed by June 6, according to Talbot.

The paving and other improvements are expected to cost about $2.5 million.

“The project is to ensure the bridge has a smooth traveling surface and is preserved for years to come,” the MDOT spokesman said.

Drivers should expect delays of at least a few minutes while the work is underway.