Stunned motorists discovered the man, believed to be in his 40s, lying on the northbound lane of the M80, near to Junction 4A, at around 12.30pm on Saturday, September 1.
Police say the man fell from the overhead bridge on to the M80 and was then struck by a Honda car on the road.
The road was closed northbound between junction 4 and 5, and local diversions were put in place.
Police advised they have now identified the man after putting out an appeal over the weekend.
Sergeant Stuart Bell, of the Road Policing Unit in Glasgow, said: “We are keen to trace any witnesses who saw the man falling from the bridge, in particular the driver of a tipper lorry who was also travelling northbound at the time.”
Witnesses are urged to contact police on 0141 532 6400.
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