Enhanced CTM for Bus Travel Simulation

Travel time and potential traffic congestion positions are important information to be considered when planning a bus route. Besides that, connected buses can communicate the expectation of arrival for passengers and the traffic control center. These values can be obtained through urban traffic simulation models based on hydrodynamics. Traffic behavior and fluids dynamics are comparable due to their resemblance regarding acceleration, density, and velocity dimensions. Among such models, the Cell Transmission Model (CTM) shows to be a suitable approach for its capacity to correlate the flow of vehicles on the road with hydrodynamics behavior. Therefore, this study proposes a CTM enhancement that computes the travel time considering different types of vehicles, traffic lights and bus stops delays. To validate the model, real traffic flow and position of traffic lights data of a district located in the city of Porto Alegre, Brazil, was collected and inserted in the model. The simulated travel time was compared with Google Maps data from the year 2019 and obtained a difference of 5.88%. Therefore, the results show that simulated travel times are similar to the observed data, proving that the designed model represents reality. The enhanced CTM also performed a bus simulation considering the size and predetermined occurrence of bus stops in the path. The model developed in this study is a potential tool to simulate travel time and identify bottlenecks and transmit this information through connected vehicles (CV).