gravelling
n.β Β«Soweto youths aren’t alone in their crazy train-surfing habits.…Typically spurred on by whistles and admiring female looks, young train surfers will variously run against the walls of bridge underpasses (βThe Matrixβ), drag their feet on the ground (βgravellingβ), or run noisily along platforms (βspara-sparaβ).Β» ββThe Big Picture: Train Surfing” by Sean O’Toole Times (Johannesburg, South Africa) Oct. 28, 2007. (source: Double-Tongued Dictionary)