关于在城市道路交叉口设置禁入区的理论分析

Theoretical Research on the Set of Forbidden Area in City Road Intersection

道路交叉口是城市道路的重要组成部分,其通行能力会影响到整个城市路网。因为交叉口处的时间资源需要分配给各相位的车流,所以其通行能力往往小于相邻路段的通行能力,也因此导致交叉口排队和交叉口拥堵等现象,使得城市路网的交通效率受到限制。以上海市的早高峰时段为例,机动车在通过交叉口时存在较为严重的拖尾现象,使得城市路网的交通效率降低。为了降低车辆在交叉口处的相互影响,可以考虑在交叉口处设计车辆禁入区。在这个区域内,各向车流要求不能停留,配合交通信号控制,将有效地引导交叉口内各向车流分离运行,进而保障交通畅通有序和交通安全。通过对道路交叉口禁入区(十字型)进行理论分析和计算,获得了禁入区的重要参数。通过对不同相位配时条件下道路交叉口禁入区设计参数的分析,获得了设置禁入区时可以采用的一般算法。从长远看,该区域的设置和相关执法方式的改变可解放一定数量的警力,并有效改善道路通行秩序。

Road intersection is an important component of urban road,and its capacity will affect the entire urban road network.Because the time resources at intersections need to be allocated to each phase of the traffic flow,their capacity is often less than the capacity of adjacent roads,resulting in the intersection queuing and intersection congestion,making the city traffic efficiency to be limited.Taking the morning peak hour in Shanghai as an example,there is a general phenomenon of tailing when the vehicle passes through the intersection,which reduces the traffic efficiency of the whole urban traffic network.In order to reduce the influence of vehicle at the intersection,we can consider a set of forbidden area at the intersection.In this area,the traffic flow cannot be stopped,and the traffic signal control will effectively guide the separation of the traffic flow at the intersection,thus ensuring the smooth flow of traffic and traffic safety.Based on the intersection of forbidden area(Cross shaped)by theoretical analysis and calculation,important parameters of the exclusion zone are obtained.Through the analysis of the design parameters in forbidden area under different signal setting,the algorithm for setting forbidden area is developed.In the long run,by setting up the region and changing relevant law enforcement methods,a considerable amount of police force can be liberated and the road traffic order can be effectively improved.