BANGOR – Lisa Baldacci, the younger sister of Gov. John Baldacci, was injured in an accident Tuesday afternoon when the car she was driving collided with a tractor-trailer on Interstate 95.

The 42-year-old Bangor woman was being treated at Eastern Maine Medical Center for what was described by police as a broken foot and injuries to her shoulder and neck.

The driver of the tractor-trailer was identified as Francis Matte, 25, of Quebec. He was not injured in the accident, which occurred about 3:30 p.m. in the southbound lane of I-95 near Union Street in Bangor.

Maine State Police Trooper Dan Ryan said that after Baldacci’s car, a 1995 Mazda convertible, and the tractor-trailer collided, the car went off the interstate and hit a granite embankment.

The accident remains under investigation. Ryan said he still had to interview several witnesses as well as formally speak with Baldacci. It wasn’t known whether she was wearing a seat belt. She was not ejected from the vehicle.

A spokesman for Gov. Baldacci said that Lisa Baldacci was in “good shape” and that the governor intended to visit her today.

Spokesman Lynn Kippax, out of deference to the family, declined to say more about Lisa Baldacci’s condition.

“Any details regarding her condition should come out of the family,” he said. “It’s a personal family matter, and that’s where it should stay.”

Traffic was reduced to one lane on the interstate as a safety precaution and to allow for removal of the car, Ryan said.