中文摘要：

交通量的迅猛增长导致传统的城市道路环形交叉口易发生拥堵,其主要成因为无信号控制下,车辆无序争先通过交织段,冲突车流导致排队长度增加,延误增大.故本文就环形交叉口信号控制问题,采用双重信号左转两步控制策略,对四向环形交叉口的车辆运行状态评价指标的选用进行了分析.根据十字交叉口的四相位控制规则,可将环形交叉口的相位方案改进成两相位双向左转,并协调配置信号控制机.以赣州市南门广场环形交叉口为实例,运用VISSIM微观仿真软件实现了不均衡流量布局下,设置相应让行规则和信号配时参数后的动态仿真.评价结果表明,非过饱和情况下不对称控制方案具有一定优势,使得车辆可以连续快速通过相邻环道信号灯,有效地利用交叉口的时空资源,改善了长期拥堵局面.

英文摘要：

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.