Optimization of roundabout control method based on dissymmetry

From developed, the Signal Control Method at Roundabout (SCMR) has been applied in some cities in China and created lots of benefit. However, it still had some problems. For example, the disequilibrium of saturation-degree caused by symmetrical control method and the low using rate of the green time. In this paper, the optimization of control method based on the dissymmetry of roundabout at coordinated control system is put forward. This new method, which is based on the "Left-turn with two stops" control method, takes the equilibrium of saturation-degree as a target and optimizes the control method of roundabout. By using the square deviation of the saturation-degree of the roundabout, this new method was evaluated. A practical application in a roundabout in Xiamen was proposed to verification the feasibility and practicability of this optimum control method.