Yeah. As someone who sits in the very back of the bus, when the bus goes over a bumpy road, or pothole at 40mph, while my bus ALREADY has very bouncy suspension, i sometimes clear a feet or two off the seat, and my bus is one of those which DON'T have seatbelts. Once i almost hit my head on the ceiling because the bus ran through a bad pothole at 45mph (Pothole fixed already by the time you are reading this).