The safe transport of hazardous materials is emerging as a significant concern impacting local, regional, and national transportation policy. For this reason, there is a pressing need to develop methods for evaluating alternative shipment routes, and for developing emergency preparedness and evacuation plans in the event that a hazarodous cargo spill occurs. Because the analysis of hazardous materials shipping and handling necessarily involves a close interaction between the transport system and its surrounding environment, the advent of the geographic information system (GIS) provides important opportunities for providing improved decision support in managing safe transport. GIS applications are defined for hazardous materials transport problems, and the benefits that can be achieved through adaptation of GIS to this subject area are demonstrated. In this context, the following information is presented:(a) the decision environment for managing hazardous materials shipments,(b) GIS data availability to support analysis needs,(c) application of a first-generation GIS model to identify preferred hazardous materials shipment routes,(d) comprehensive approaches using GIS for emergency preparedness and evacuation planning, and (e) problems encountered in using GIS technology for hazardous materials transport applications. A GIS approach offers potential for addressing these subject areas. Models already operational today demonstrate the immediate value of using a GIS, and the future design of more comprehensive methodology should provide even greater benefits.