Signal Control Simulation and Timing Optimization Design of Roundabout Based on VISSIM

The rapid growth of traffic volume in the traditional urban road roundabout is prone to congestion.The causes are mainly no signal controland,vehicle rushing through the weaving section disorderly.The conflict often leds to long traffic queue and the extended time delay.Therefore,the control strategy of double signals and two-stop-line-for-left-turn control(TSLT)are used to solve the signal control problem,and the selection of evaluation indexes for the vehicle running state of the four directions roundabout is analyzed in this paper.According to the rules of four phase control in cross intersection,the phase scheme of roundabout can be improved into two phase bidirectional left-turn,and the setting of signal controller is coordinated.Taking the South Gate Square roundabout in Ganzhou city as an example,bg using VISSIM microscopic simulation software,the dynamic simulation,in which corresponding right-of-way rules and signal timing parameters are set up under non-equilibrium flow layout is realized.Evaluation results show that the non-supersaturated case asymmetric control scheme has certain advantages.Vehicles can continuously and rapidly pass the adjacent signal light in the roundabout,and use the time and space resources effectively.Thus the long congestion situation is optimized.