机动车左弯待转区设置的临界条件

为寻求左弯待转区的设置依据,分析了交叉口的几何形状,给出了设置左弯待转区的几何临界条件;利用累计曲线和交通波理论建立了左转车排队位置模型,如果交叉口的渠化方案和信号配时方案保持不变,应用排队位置模型可以得出在排队长度约束下的临界流量和极限流量;如果左转车的到达率一定时间段是稳定不变的,可以得到设置左弯待转区的左转相位最短绿灯时间和最长红灯时间.研究成果可为左弯待转区的设置提供理论依据.

Critical Condition for Setting Left-turn Waiting Area

To seek the theoretical foundation for the layout of the left-turn waiting area, the geometry of the intersection was analyzed, and the geometrical critical condition for set up left-turn waiting area was put forward.The model of left-turn queuing location was established based on accumulation curve and traffic wave theory.On the condition that channelization and signal timing method of intersection is invariable, the critical volume and limit volume under the restriction of queue length according to the model can be found out.If the arrival rate of left-turn vehicles is stable in a certain period of time, the minimum green time and the maximum red time of left-turn phase of the left-turn waiting area can be obtained.The result provides a theoretical basis for set up left-turn waiting area.