SYSTEM SAFETY/RISK ANALYSIS TECHNIQUES APPLIED TO MOTOR VEHICLES AND RAPID TRANSIT SYSTEMS

Since 1969 Booz, Allen & Hamilton Inc. has performed safety analyses of a number of ground transportation systems. The analyses were directed at the automobile, the transit bus, and the rail rapid transit system. Fault tree analysis techniques were used in all three cases. This paper discusses the utility of fault tree analysis techniques in setting safety requirements and goals for new equipment designers and system managers. The prioritization of safety requirements and goals was obtained through effects or cost benefit analyses and was an integral part of the fault tree analysis technique. The safety analysis of the automobile was confined to component degradation as a causation factor in automobile accidents. The transit us safety work analyzed over 92 types of accidents, both onboard and offboard. Two major outputs were derived from the safety analysis of rail rapid transit systems; these were safety criteria and a system safety program plan for the future design and development of such systems. In all three transit modes the analytical methodology, results, and conclusions are presented. /Author/