FRANKLIN TOWNSHIP - State police say an 85-year-old man walking on a highway in Somerset County was struck and killed by a tractor-trailer.

The accident on the northbound side of Interstate 287 in Franklin Township was reported around 10:20 a.m. Monday. Authorities say Miroslav Bodnar was walking near Exit 12 when he was struck.

Bodnar, of Franklin Township, was pronounced dead at the scene. 

Authorities say that it is still unclear why Bodnar was on the roadway.

State police say there was a vehicle on the right shoulder of the roadway at the time of the accident. But authorities don't yet know if Bodnar had been driving it.

The truck driver was not injured in the accident.

The cause of the accident remains under investigation.

The Associated Press wire services contributed to this report.