Green’s Dictionary of Slang

(S.Afr.) one who clings to the outside (or stands on the roof) of a moving train, having boarded it while it is in motion; thus staffriding n.

1977		P.C. Venter Soweto 81: Clinging to the side of a fast train is dangerous — but not dangerous enough for some of the ‘staff riders’. There are those who prefer to travel on the roof of a train ... The mortality rate of so-called staff riders is high.
1980		B. Setuke ‘Dumani’ in Mutloatse Forced Landing 59: It goes without saying that the first people to board the train will be the ‘staffriders’, as they have come to be known. [...] These guys jump into the train while it is still in motion.
1996		V. Erlmann Nightsong 319: An old man, trying to demonstrate his bravery had imitated the ‘staffriders’—young men riding on the outer steps of railway cars.
2000		C. Glaser Bo-tsotsi 143: And sometimes you had to do some staffriding [moving on the outside of the coach, along the sides or the roof].