Development of Prototype Decision Support Systems for Real-time Freeway Traffic Routing

About the report:

For a traffic management system (TMS) to improve traffic flow, TMS operators must develop effective routing strategies based on the data collected by the system. The purpose of this research was to build prototype decision support systems (DSS) for the real-time development of such strategies. We used the freeway system controlled by the Suffolk (Virginia) TMS as a test case. A routing DSS has (1) a search mechanism that allows the space of possible routing strategies to be explored thoroughly but efficiently, and (2) an evaluation routine that estimates the effectiveness of a particular strategy. We combined the search and evaluation routines to develop two DSS prototypes: a simple shock-wave DSS that required very little input data and a heuristic search/dynamic traffic assignment (DTA) DSS that demanded more input and computations but captured traffic dynamics better. We evaluated the prototypes based on the agreement of their recommended strategies with prior expectations and their potential for real-time applications. The results are promising. For the shock-wave DSS, the diversion percentages recommended agree with prior expectations. For the heuristic search/DTA model, the results are consistent regardless of the start point for the search algorithm.

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