The man was moving around beside his own vehicle on the three-lane road, when the incident happened.
His car was stationary in the central lane, behind another that it was in convoy with and the roads were relatively quiet.
In the footage, captured by a passenger in a car in the inside lane and published on liveleak.com, he appears to walk around the side of the silver people wagon, heading for an open boot, which he is looking towards.
Behind him a second car pulls up but others on the road are not so patient.
A black car swings out so as to overtake the line of stopped vehicles as the man reaches the trunk and strikes him with such force that he is flipped up onto its bonnet.