The methodologies of hazardous materials transportation risk assessment

Intense interest now exists in the potential of risk assessment as an aid to public and private decision making on hazardous activities. Inadequacies in its methodologies and supporting data have nevertheless so far limited its efficacy in practice. Among attacks on the problem of improving this efficacy is a project supported by the National Science Foundation which identifies and focuses on improvements in particular areas of uncertainty in risk assessment methodologies. This paper presents some of the project's material that pertains to hazardous materials transportation. It overviews the general risk assessment problem, presents a structured review of the types of methodologies employed in estimating the contribution to risk of the different phases of a hazardous material incident, and then reviews the procedures available for the evaluation of the significance of the risks estimated, and of potential means for their mitigation. Comments are made throughout, and in the paper's conclusions, on the problems arising in these estimation and evaluation processes, and on general approaches to their resolution.