CONCLUSION
This paper describes a basic model for evaluation of route rationaliza- tion as a means of reducing the risk from rail transport of hazardous materials. The purpose is to introduce and illustrate the concept and to explore the potential benefits that may be possible. A simple case study is considered based on the route structure of a TIH transported in railroad tank cars. The results indicate that for the product evalu- ated, route rationalization can reduce mileage, accident probability, release probability, population exposure, and risk. In general, the extent of risk reduction possible will depend on the characteristics of the traffic pattern and other constraints of the particular opti- mization problem. For purposes of illustration and brevity, the authors relaxed some constraints in this study, including neglecting the possibility of schedule conflicts or track unavailability, and did not account for possible temporal variation in production capacity or demand. However, the model was structured so that it can be adapted to incorporate these and other factors, thereby enhancing its general applicability.