Motorists in the area of Gray and New Gloucester should be aware of two bridge projects that will impact traffic routes starting next week.

The larger of the two projects-repair of the Libby Brook Bridge on Mayall Road in Gray near Route 100-will close the Mayall Road starting Tuesday, July 15. Work on the bridge should continue until the end of August, and detours will be available via Bennett Road, Snow Hill Road, and Sabbathday Road, said Bruce Pelletier, spokesman for the Maine Turnpike Authority.

Also, the Maine Turnpike Authority will be working on the Mayall Road Underpass in New Gloucester next week during the overnight hours. Traffic in that area on Mayall Road and the Maine Turnpike around mile 67.5 will be stopped two or three times per night for up to 25 minutes at a time, Pelletier said. The work will be done 10 p.m.-5 a.m. Monday through Friday next week, he added.

The Libby Brook Bridge is in desperate need of repair, Pelletier said.

“The bridge has been posted for weight limits because it’s deteriorating,” Pelletier said. “The plan is to close the road and rebuild the bridge.”

The bridge is used by fewer than 1,000 vehicles a day, Pelletier said. By contrast, some Turnpike Authority bridges see 12,000-14,000 a day, he said.

“It is very light trafficked,” he said.