DynasTIM: A Real-time Online Traffic Simulation and Optimization System

DynasTIM is a real-time software system that can be used for the online simulation, prediction and optimization of dynamic traffic flows in urban and intercity networks, thus provide information and decision support for Intelligent Transportation Systems(ITS). DynasTIM has been developed by the author for around 15 years. It was originally designed as a simulation based dynamic traffic assignment system. What follows is the addition of some new features, including the application and functional architectures of the system, dynamic OD(Origin-Destination) flows estimation based on analytical assignment matrices, mesoscopic traffic model with variable-length speed influence region and online speed calibration capability based on probe vehicles and connected vehicles data, and urban area signal optimization with parallel SPSA algorithm. DynasTIM achieves the functionality through three modules: state estimation (ES), state prediction and control strategy optimization (PS&CSO), and guidance strategy optimization (GSO). The case study is based on a populated network from the Futian Central Business District (CBD) in Shenzhen, China, with the area of around 7 square kilometers. DynasTIM was calibrated for the network with archived data including the turning counts collected from 359 video detection locations, to validate the capability of reproducing the real-world traffic conditions, and establish basic conditions for the signal optimization method. Results indicate that it is capable of reproducing the actual traffic counts fairly well. We also evaluated the signal optimization method for the network with 38 signal control intersections, which led to better-performing signal plans and around 13% reduction in the average travel delay, in comparison with the plans currently implemented in the field.