Ejection of Passengers in Bus Rollover Accidents

Abstract

The rollover is the most severe, dangerous bus accident. If the weak superstructure collapses in the rollover, the passengers are compressed and killed, or seriously injured. Requiring specified roof strength—UN-ECE. Regulation 66.—the severity of bus rollovers were significantly reduced. Later it became clear that another problem—belonging to the rollover accidents, too—the ejection of the passengers from the bus remained unsolved. Some case studies and statistical data are shown in the paper to present the ejection. Two kinds of ejections exist: the total ejection, when the passenger gets out completely from the passenger compartment, and the partial ejection, when only the head, shoulder, chest, arms, and the lower parts of the body remain inside. The injury mechanisms are discussed in the paper. The reason of the ejection is the broken side window. It is not allowed to use laminated safety glass as side window, because the side windows are generally used as emergency exits. The paper proves that the side windows are not needed as emergency exit and the breakable side windows are absolutely unusable as emergency exit. Nowadays it is hoped that the retention of the passengers may be solved by the obligatory use of safety belts. The paper shows that this assumption is faulty; the safety belts have more disadvantages than advantages in rollover. When the bus is lying on its side after a rollover accident, and the passengers are wearing their safety belt, they are hanging in a very unusual position and they cannot release the loaded safety belts. On the other hand, the safety belt can prevent the projection and total ejection, but it is almost ineffective against the partial ejection. In the UN-ECE organization there are different efforts—the author is participating in this work—to solve this problem, but there is no one good solution, because the problem is very complex (obligatory use of safety belts, laminated safety glazing, emergency exits, etc.). The paper tries to give a clear picture about the problem—which is an essential, newly recognized issue in the bus safety—and showing the possible ways to the solution.

F2012-F02-005