Officers arrived at the scene shortly after midnight on Thursday morning.
Forth Valley police are appealing for information following the death of a 47-year-old man in Bonnybridge.
Police were called to Station Road at 12:10am on Thursday, underneath the M80 Overbridge.
Detective Sergeant Andy Gardner said: “We are working to establish the circumstances surrounding his death and it is currently being treated as unexplained.
“Around 10.50pm on Wednesday, he had been driving his silver-coloured Ford Fiesta northbound on the M80 just after the Haggs junction, when his car broke down and he stopped on the hard shoulder.
“We would appeal to anyone who was driving on the motorway between 10.45pm on Wednesday night and 12.10am on Thursday morning, when police were called. If anyone saw the silver-coloured Ford Fiesta at the side of the motorway, please get in touch. I would also appeal to any drivers on that road between those times who have dash-cam footage to contact officers.”
Report into Falkirk Council finances
Rise in spiking incidents
Concern over Forth Valley road casualties
Falkirk and Grangemouth Growth Deal signed