Risk analysis of hazardous materials transportation: evaluating uncertainty by means of fuzzy logic

This paper provides an application of fuzzy logic to the risk assessment of the transport of hazardous materials by road and pipeline in order to evaluate the uncertainties affecting both individual and societal risk estimates. In evaluating uncertainty by fuzzy logic, the uncertain input parameters are described by fuzzy numbers and calculations are performed using fuzzy arithmetic; the outputs will also be fuzzy numbers. This work is an attempt to-justify some of the questions the use of fuzzy logic in the field of risk analysis stimulates. This study provides, first of all, a condensed description of the fundamentals of the mathematical procedures which perform the risk measures calculations. Then, some basic concepts about fuzzy logic and fuzzy arithmetic are introduced, after which an explanation on how the uncertain input data can be represented by fuzzy numbers is made. Finally, test results of combined uncertainty and sensitivity analysis in the risk evaluation of a toxic gas release are presented and extensively discussed, in order to show which effect each uncertain input has on the output uncertainty. (C) 1998 Elsevier Science B,V. All rights reserved.