Simulation of the complete operation of a bus rapid transit system using cellular automata

Many cities in the world have implemented Bus Rapid Transit (BRT) systems as a part of their public transportation networks. BRT systems are highly efficient and relatively low cost when compared to rail-based systems. In Colombia, BRT systems are the main public transportation solution in many cities such as Bogotá, Cali, Barranquilla or Pereira. One of the major challenges in BRT systems is the formation of bus queues at busy stations, which reduces the performance of the entire system. The modeling of these queues is challenging as they arise from the complex interaction between the station’s geometry, the service frequencies and the passenger demand. In this paper, we present a complete microsimulation framework for the Megabus BRT system in Pereira based on cellular automata. The simulation introduces two kinds of agents: buses and passengers, and they interact to reproduce realistic behavior. Our results show that the simulation can reproduce queues formation and delays arising from the interaction between buses and with traffic lights. Our framework allows the evaluation of different service frequency schemes from the operator’s and the passenger’s point of view, which makes it a suitable tool to solve the frequency optimization problem successfully accounting for bus delays.