8. Conclusions
The study addresses both supply and demand aspects of the response to adverse weather, including user responses to various weather-specific interventions such as advisory information and control actions. The procedures implemented provide immediately applicable tools that capture knowledge accumulated to date in the growing body of literature regarding weather effects on traffic (especially in an aggregate sense). The application to a real world network shows that the proposed model can be used to evaluate weather impacts on transportation networks and the effectiveness of weather-related VMS.
The high level framework for incorporating weather impacts in TrEPS, presented in this study, provides a direction for future development towards a modern approach to traffic management under adverse weather that recognizes modern technological developments (e.g. weather sensing/forecasting, weather responsive traffic management). In addition, heterogeneous user response to road weather information, reflecting their different risk taking behavior, can also be calibrated and included in a richer router choice model in future study.
While the work accomplished as a result of this research effort advances the state of the art in incorporating weather effects in network analysis tools, additional effort in two main areas is necessary to translate these advances into practice. The first entails actual implementation in the context of a regional planning and/or traffic operations agency to establish the model and calibrate it for application under a variety of local conditions and traffic patterns. While the developments under this project provide all necessary mechanisms as well as default values for most likely situations, only through actual application within a progressive agency committed to providing information to users and to developing measures and plans to deal with weather-related problems will the state of practice fully advance to the desired level.
The second area of development would focus on weather-related traffic management and control measures, and interfacing their actual deployment with the decision-support tools developed in this project. Again, the mechanisms included in this development were in certain cases based on proposed control measures that may have seen no or limited deployment. Actual field testing and monitoring can provide essential data to calibrate and refine these mechanisms. Furthermore, achieving the full benefits of traffic estimation and prediction tools for the intelligent management of traffic systems under weather-related events requires additional development of the real-time components of these tools, and their interface with real-time sensors and weather prediction sources.