Although it probably wouldn't work in every case.
It's been a couple of years since a Cleveland bus driver became internet famous for upercutting an unruly passenger who refused to pay, and then berated and spit on him. But bus passengers everywhere have continued on being unpleasant, as the following video will show. Of course, the scale of unruliness is very different from the incident in Cleveland, and the bus driver stays level-headed enough to solve the problem effectively without violence.
This might not have worked on a passenger who was able to move a bit faster, but it did work.