Wind forces and aerodynamics: contributing factors to compromise bus and coach safety?

摘要

A bus in motion is affected by aerodynamical side and lift forces that may interfere with the stability of the vehicle. These forces depend on the speed and direction of the resulting wind in relation to the bus. Cross-wind gusts may generate side forces so suddenly that great directional deviation is imposed on the bus prior to any possible driver or vehicle manoeuvre responses. Prevailing friction forces may not be sufficient to enable the driver to avoid large lateral deviation from the desired route, and can potentially lead to crashes. The present study, based on ten bus crashes, aimed to show that the effect of wind, in addition to vehicle speed and road friction, is a contributing factor to compromising bus safety. The results of the study confirmed that wind, in relation to vehicle speed and friction, needs more attention when addressing the pre-crash factors in crash investigations, bus manoeuvring capacities, operational management, and the aerodynamic design of buses.