Modeling and Visualization of Traffic Flow at Roundabouts Using Cellular Automata

The paper presents a cellular automata model for the simulation of traffic flow on a network including multi-lane roundabouts. An algorithm for bypassing bottlenecks is developed, allowing vehicles to enter and exit roundabouts while respecting priority and safety requirements. The roundabout routing algorithm uses the Manhattan distance as the path cost to the desired destination and guarantees reaching the destination in the optimal way. The new model is integrated into the original traffic visualization environment, TrafficFlowViz3D. For verification, traffic was simulated in a closed system consisting of four two-lane roundabouts connected by two-way straight road sections. Discrete results of the calculation were averaged over time and space for all network elements. The expected benefit of introducing a second lane at roundabouts compared to single-lane traffic was obtained, and an increase in the average speed per a straight section was demonstrated with increasing section length. The system under consideration will be further studied in the steady-state mode using the macroscopic fundamental diagram. The problem of system self-organization is also of interest. The developed mathematical and software tools can be applied to predictive modeling of urban traffic.