Effects of Turning Maneuvers and Route Choice on a Simple Network

A simple symmetric network that consists of two tangent rings on which vehicles obey the kinematic wave theory of traffic flow and can switch rings at the point of tangency is studied. An online adaptive simulation reveals that if there is any turning whatsoever, the two-ring system becomes unevenly loaded for densities greater than the optimal density, and reduces traffic flow. Furthermore, the two-ring system jams at significantly lower densities than the maximum density possible.