Hierarchical multiresolution traffic simulator for metropolitan areas architecture, challenges, and solutions

This paper presents a hierarchical multiresolution traffic simulation system for metropolitan areas, referred to as METROSIM. Most multiresolution traffic simulation systems are single level, and different simulators represent different portions within the same network. In contrast, METROSIM has two hierarchical levels: an open-source mesoscopic traffic simulator for regional dynamic traffic assignment (DTALite) and a popular commercial microscopic traffic simulator (PTV VISSIM) for intersection and corridor traffic operations. Unlike the traditional network modeling method, METROSIM starts from the microscopic simulation network and migrates into the mesoscopic network while reserving all the high-fidelity details, such as geometric design and signal head locations. The DTALite network and the VISSIM network represent two independent but highly consistent networks, and they exchange data while both simulation engines are running to overcome some long-standing issues in single-level systems, including the consistency of network representation and route choice, computing efficiency, and precise simulation of the subareas with the greatest interest. This paper offers insight into the development of multiresolution systems and focuses on topics such as network migration, parallel computing, and interprocess data integration. A case study demonstrates the potential applications of METROSIM.