Pas age of the 1990 Hazardous Material Transportation and Uni· form afety Act in tl1e United State· will result in state de ignati n of hazardou. materials through routes. Several alternative criteria have been recommended for consideration in implementing this policy, many of which represent explicit trade-offs in terms of safety and operating erficiency. The impact of using alternative criteria and criteria weighting for route selection is explored. This is examined through the use of a network analysis tool designed explicitly for hazardous materials distribution risk management. A study region consisting of the truck highway network in Southern California i used to illustrate several coo ideration that will need to be addressed during the implementation process. A number of findings are reported concerning route selection, risk equity, public perception, and emergency prcparedne s. llect. ively, they identify the types of problem that may be encountered in the establishment of routing guidelines by the· caccs implementation of state route selection procedures, and issues related to federal preemption. Areas in need of additional tudy are also described. with an eye toward eswbli hing ome tandardization in approach and perhaps analysis to Is thar would satisFy both state m1d industry concerns.

The safe movement of hazardous materials (including wastes) is receiving increased attention because of growing environmental awareness of the potential health effects of a releasecausing incident. Pressure has been placed on the regulatory process to designate routes for dangerous goods transport that emphasize safety considerations. Notwithstanding the importance of operational safety, the efficiency with which these movements occur remains an important objective. The significance of this problem is apparent. It is estimated that 1.5 billion tons of hazardous materials are shipped annually across the nation's transportation systems (excluding pipelines); moreover, these volumes are growing (1). As these shipments occur between large numbers of shipping and receiving points in the continental United States, routing policy will have a profound effect on the pattern and volume of hazardous materials flow.