As public concern grows over the safely of hazardous malerials trans_port, more policy emphasis is being placed on a essing the relative and ab olute ri ks ot'arious operations strategics. This is parUcularly apparent in the face of recent catastrophic events worldwide involving hazardous material. At pre ent, compre· hensive hazardous materials transport risk assessments are diffi. cult because of the paucity and poor quality of empirical data. These data problems are most acute for the rare, catastrophic event that is of primary concern to public safety officials. For these reasons, many approaches to risk estimation can be considered. This pa1> er describes alternative approaches to hazardous materials trnnsport risk estimalion under conditions of limited data availabilit, including consideration of statistical inference, fault/event tree modeUng, analytical and imulation techniques, ub· jective e timaUon, and Bayesian analysis. The hawrdou'materials lran porl problem is examined in terms of the feasibility of applying these techniques. Concern is raised over the likelihood of dif· fercnt approaches r• ulling in conmcting risk estimate and a procedure for mediating these conflicts is discussed.

As public concern grows over the safety of transporting hazardous materials, more policy emphasis is placed on assessing the relative and absolute risks of various operational strategies. At the heart of this problem is the subject of risk estimation. Traditional approaches to transportation systems analysis have focused on economic analysis and, consequently, much is known about operating costs and costing methodology; however, transport risk estimation is only now reaching adolescence.