The paper uses two areas of past and present concern over transportation safety as examples of the problem of determining cost-effectiveness of safety programs. In one area, rail-highway grade-crossing safety fatalities have been greatly reduced in the decade of the 1970s. The safety program has been very successful, but now there are those who say the cost has been too great relative to the numbers "saved," and future programs may be endangered. In the other area, hazardous materials transportation accidents/incidents fatalities are even fewer, but the trend is to spend ever increasing amounts on safety programs. The paper asks several questions: How should cost-effectiveness be evaluated in these two areas? When is it appropriate to say the level of deaths has reached a point where a program should be shut off? Are traditional effectiveness measures appropriate in these areas? The paper uses a critique of the massive highway safety program of the 1960s as a base for exploring appropriate philosophy to approach these issues. From appropriate literature, the case is made that too much concern was given to funding and attacking specific accident causes and specific system components. Also, safety was too often treated as an end in itself rather than a by-product of mobility. The point is made that with a given level of mobility desired, there is an associated cost and risk. When one keeps in mind that mobility is the paramount issue, then it is appropriate to develop a risk, mobility, and resource relationship within specific goals and constraints. The author relates the above philosophy to rail-highway grade-crossing safety and hazardous materials transportation safety. Rail-highway grade-crossing accidents and hazardous materials incidents are rare events. It is extremely difficult to collect sufficient data to develop traditional effectiveness measures. This fact is particularly true in the areas of hazardous materials and vehicle/train collision if effectiveness is measured in terms of casualties or fatalities. But these are high-risk situations and should not be ignored~ for example, in both areas, the possibility of a catastrophic event exists. Since traditional risk analysis takes into account the product of the probability of an occurrence and the consequences, "catastrophic potential" is taken into account. In these and similar areas, it is concluded that risk analysis methodology should be perfected and utilized. When one determines what level of risk is acceptable for a desired level of mobility in a system, then, and only then, can it be determined what level of expenditures is appropriate or if an "acceptable" bottom line of accident reduction has been reached. The paper concludes with a brief synopsis of the state-ofthe-art of risk analysis models, insofar as their current utility in the two areas discussed. (Author/publisher)
Samenvatting