Traffic flow behavior at a single lane roundabout as compared to traffic circle

• Simulations are conducted to study traffic flow at a single-lane urban roundabout as well as traffic circle.
• Phase diagrams for roundabout as well as traffic circle are constructed.
• The performance of the two systems are compared in terms of the geometrical properties and the number of entry points.

In this paper, we propose a stochastic Cellular Automata (CA) model to study traffic flow at a single-lane urban roundabout (resp. traffic circle) of N   entry points (resp. exit points), the entry points are controlled by rates α1α1 and α2α2 while the removal rates from the exit points are denoted by β. The traffic is controlled by a self-organized scheme. Based on computer simulation, density profiles, global density and current are calculated in terms of rates. Furthermore, the phase diagrams for roundabout as well as traffic circle are constructed. It has turned out that the phase diagrams consist essentially of two phases namely free flow and jamming. It is noted that the typology of the phase diagrams of the roundabout is not similar to it in the traffic circle. Furthermore, we have compared the performance of the two systems in terms of the geometrical properties and the number of entry points.