绿闪信号作用下城市道路交叉口两难区研究

为了提高绿闪信号作用下交叉口的交通安全，基于进口道机动车微观行驶特性开展了两难区研究.在绘制机动车停车及通过行为曲线的基础上，获取了两难区的临界位置，界定了两难区的分布范围，求解了机动车陷入两难区的概率，剖析了道路限速及绿闪时长与两难区分布之间的关系.最后通过具体实例表明，在道路限速为50 km/h 的情况下，两难区分布在离停止线48 m左右的位置；现有2.56 s 的绿闪时长能够保证机动车不会陷入两难区的最大行驶速度为56 km/h.两难区的研究成果有助于合理设计绿闪时长和道路限速，从而消除两难区的负面影响，为交通控制与管理提供理论支撑.

Dilemma Zone of Urban Intersection Based on Effect of Flashing Green

In order to enhance intersection safety, dilemma zone is studied based on the microscope driving characteristics of vehicles on the intersection approach. The critical position and boundary of dilemma zone is determined based on the curves of crossing and stopping decisions of vehicles, the probability of being caught in dilemma zone is calculated out, the relations of dilemma zone between the length of flashing green and speed limitation are analyzed. The results of a case study indicate that the dilemma zone is 48 m away from stop line when the speed limitation is 50 km/h, and the vehicles would not be caught in the dilemma zone, of which speed is not over 56 km/h when the existing flashing green length is 2.56 s. The study of dilemma zone is helpful in designing reasonable length of flashing green and speed limitation, and eliminates negative effect of dilemma zone, and provides theoretical support for traffic control.