Troy Aughton and two friends were riding in the forest on Sunday afternoon when the 45-year-old came off his bike.

The Moss Vale Dux Hot Water employee suffered significant injuries and was taken to his home in Sunset Point Drive, Mittagong.

The Ambulance Service was called at 4.25pm but he died a short time later.

A CareFlight helicopter was on route to airlift the man from Ironmines Oval but was called off.

A post morterm examination into the cause of death will be conducted tomorrow. Bowral Police are preparing a report for the Coroner.

Earlier on Sunday, the Hume Highway north of Goulburn became a carpark afternoon when a prime mover rolled onto its side following a two-vehicle accident.

At 10.30am, police and emergency services responded to reports a truck had overturned on the highway south of Marulan.

Police said a truck and car collided while travelling north on the highway. The driver of the car received minor injuries and was taken to hospital. The truck driver was uninjured.

The highway experienced heavy delays and traffic jams with only one lane northbound opened and rain slowing the salvage operation.

Traffic was banked up 27km back past Goulburn with one motorist saying it took seven hours to get from Canberra to Wollongong. The highway wasn’t re-opened until 8pm, police said.