Abstract
ABSTRACT
Accident statistics show that the rollover is a rare accident of buses (3-6% of all bus accidents in which persons are injured) but it is a very serious one, because it causes around 50% of the severe casualties (fatality, serious injury) of all the casualties in bus accidents. UN-ECE Regulation 66. regulates the required strength of bus superstructure in case of rollover. Regulation 66. has three key issues: the so called standard rollover accident situation, in which the bus occupants shall be protected, the survival space which shall be preserved for the bus occupants in the standard accident and the approval test methods. The history of the standard rollover accident and the development of the approval test method showed that the real severity of an accident can not be established at first glance. Sometime the more spectacular rollover test can provide less dynamic load on the superstructure. It is a very important requirement that the standard accident shall represent the same type of dynamic loading for all kind of buses (mini, midi, low-floor, high decker, traditional, double decker, etc.) Regulation 66. has a serious deficit in this respect, the applied rollover test is not appropriate for high decker and double decker coaches and it is not used for smaller buses.