A failing bridge on Acushnet Road is slated to be replaced next summer, Highway Surveyor Barry Denham told the Mattapoisett Board of Selectmen on Wednesday.

Using the $500,000 small bridge grant the town received from the state, Denham said the project will be completed during the summer months so any detours won’t disrupt school bus routes.

“The existing bridge was constructed of railroad ties and had timber on concrete on top,” said Kim Armstrong, a consultant working with the town. “The timber is mostly rotted away.”

The plan for the bridge will be compliant with the state’s Complete Streets program, which ensures accessible and pedestrian-friendly local roads.

Denham added that the plan widens the road.

“It will give us two 12-foot lanes instead of two nine-foot lanes,” he said. “It’ll give a full one-foot sidewalk too, which we don’t currently have.”

Armstrong said the team had already met to discuss detours and road closures, and is working with Eversource to get the company to move utility lines prior to construction starting.

“We’re going to get all the pre-work done prior to the [road] shut-down,” Denham said.

It’s anticipated that the section of the road will be closed for two or three months, but the goal is to start when school gets out and be finished before it starts up again.

“We had traffic crossing the bridge within five weeks of starting construction last time,” Denham said about a similar project’s timeframe. “We had traffic crossing the bridge before we had completed the asphalt, and we used barriers in place of the guard rails. Our goal is to open it to traffic as soon as possible.”

Denham estimated that about 100 homes would be affected by the road closure, and that the only concern was the hassle the detours would cause for emergency vehicles.

Town Administrator Mike Gagne said he had spoken to Fire Chief Andy Murray about it, and they ran a scenario in which emergency services were required at a home affected by the road closure. Without the detour, the fire truck could make it to the home in seven minutes. With the detour, it took 10 minutes.

“It’s a pain, but we’ve got to do it,” Selectman Paul Silva said.