Simulation Framework for Modeling Large-Scale Flexible Transit Systems

Abstract

Despite the prevalent use of simulation methods in a majority of areas in transportation research, transit and paratransit research has not relied heavily on simulation models, not only because traditional transit studies do not necessarily require simulation techniques but also because proper simulation packages are not available for modeling innovative transit systems. This study proposes a new type of simulation framework, targeting large-scale flexible transit systems with various vehicle operation schemes. The intent of this study is to describe the generalized concepts and the detailed architecture of the framework developed for urban transportation networks. A comprehensive process for the framework development, including considerations of simulation data conversion and user interface design, is discussed. Two real-time flexible transit applications are modeled with the proposed simulation framework: high coverage point-to-point transit and real-time shuttle service. Detailed simulation results are provided, and the importance of simulation design and operational features is addressed. The results also show that the framework can model realistic large networks several times faster than real time with standard desktop computers; these results raise the possibility of its use in real-time optimization schemes as well as for synchronous modeling with commercial road traffic simulators.