The primary objective of this study is to demonstrate the possibility of using NetworkFundamental Diagram (NFD) in investigating the performance of integrated demand andsupply models. At the same time, it also seeks to establish how an integrated demand-supplymodel could be used to produce NFDs, which have long been used to study network flowcharacteristics. In this paper the ADAPTS dynamic activity-based model generates thedemand and TRANSIMS has been used for traffic simulation. In order to properly model thedynamic interaction between the demand and supply models, a framework has been proposedand developed that tightly integrates the ADAPTS activity-based model with the TRANSIMStraffic simulation tools. Both models have been modified to support the continuouscommunication of vehicle information between them during the course of simulation. Thisallows the ADAPTS model to have full control over its agents during the traffic simulationand to be able to update its agents’ plans and schedules when necessary. The integrated modelis then run to generate activities and simulate associated trips so as to generate the NFDs.Three hypothetical cordons of varying sizes are drawn around the central business district ofChicago to plot the diagrams. Several essential observations are then discussed in detail.These observations form a basis to validate the integrated framework. The results show thatthe observed dynamics in the simulated NFDs share certain similarities with the NFD drawnusing loop detectors data; however, some inconsistencies are observed which are discussed indetail.
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