A framework for evaluating the safety benefits of intelligent transportation systems

The benefits of ITS are indirectly represented by the annual world market for ITS, which according to ITS Canada will be CDN $90 billion by 2011. Improved safety is often cited as being the top goal of implementing ITS, followed by others relating to efficiency, economic productivity, and the environment. However, despite the magnitude of these investments and their underlying goal to improve transportation safety, and despite the inherent recognition of the safety improvement potential of ITS by transportation professionals, there is a deficiency in the quantity and quality of reported ITS safety benefits. Much of the existing evaluations and reported benefits to date suffer from the lack of an evaluation framework and inconsistent terminology used to attribute benefits to ITS application areas. In light of these issues, and the ongoing need in the ITS community to better demonstrate the safety benefits of ITS, a framework has been developed for evaluating the safety benefits of ITS. This framework is unique in that it uses the ITS application areas defined by the market packages in the Canadian ITS Architecture and categorizes and correlates them against a distinct set of metrics defined to measure the safety benefits of ITS. Furthermore, the metrics are correlated with each other to capture the "cause" and "effect" flow of benefits and how each market packages contributes to the fundamental goal of reducing the number and severity of crashes. The need for this approach has been illustrated through a case study that demonstrates the potential disparity in benefit estimates when no framework is used. This framework will benefit future evaluations of ITS safety benefits by providing a structure for undertaking evaluations and reporting of benefits, while addressing the terminology issue through an interface with the Canadian ITS Architecture. This framework forms the basis of developing similar frameworks related to measuring benefits associated with other ITS goals. Each of these individual frameworks could be linked together (via their common "cause" and "effect" metrics to provide an overall framework for evaluating all ITS benefits. This overall framework could be integrated with the Canadian ITS Architecture documentation and training programs to ensure that the evaluation of ITS benefits becomes an integral part of ITS planning and design.Applied Science, Faculty ofCivil Engineering, Department ofGraduat