Dean Geary, 19, was found on the A811 Drymen to Gartocharn road on February 7, 2010.
The teenager had died from head injuries after being struck by a vehicle but it has never been established why he was in the area.
Police last week announced they were launching a fresh probe into the case.
A spokesman said: "Dean had been out with friends in Glasgow city centre and left the Tattoo nightclub in Queen Street alone, at 2am. There were several sightings of Dean on CCTV in the city centre that morning.
"Over three years have passed since Dean's death but officers believe there are opportunities to find out what happened to him."
Anyone who has any information should email: operation email@example.com. police.uk