信号交叉口人车交互运行元胞自动机模型构建

Construction of cellular automata model of alternate operation between pedestrians and vehicles at signal intersection

为了确定过街设施的形式,分析了十字信号交叉口行人步行速度及机动车排队净空间距、转向车头时距等交通运行特性,通过对人车冲突行为调查与分析,构建了行人过街可插间隙选择概率模型.以人车交互运行特性为理论基础,建立了双向6车道行人正向前进、避让、侧向前进和机动车停车线前慢启动跟驰、停车线后转向跟驰、目标车道选择规则,引入了人行横道处行人和机动车冲突判定选择规则,将行人过街规则和机动车通行规则进行了叠加,构建信号交叉口人车交互运行元胞自动机模型.以主主相交的双向6车道十字信号交叉口为例,分析了采用行人过街专用信号相位和立体过街设施形式的适用性.结果表明:当交通量不小于4 500 pcu·h-1、右转车比例不小于70%、信号周期不小于90 s、左转相位绿信比不小于50%、行人流量不小于2 700人·(h·m)-1时,应采用立体过街设施形式.

To determine the form of crossing facilities,The traffic characteristics of pedestrians’ walking speed and vehicles’ queuing spacing, headway of steering were analyzed in signalized intersection. The probabilistic model of acceptable gap choice for pedestrians crossing the intersection was constructed by survey and analysis of conflicting operations between pedestrians and vehicles. On the theoretical foundation of characteristics from alternate operations between pedestrians and vehicles, rules concerning pedestrians walking forward, avoidance, lateral walking forward, vehicles stop？to？slow following, steering following, and target lanes selection in bidirectional six lanes were established;selective rules concerning conflicts identification between pedestrians and vehicles at pedestrian crossroads were introduced. Therefore, the cellular automata model of alternate operations between pedestrians and vehicles at signal intersection was constructed through overlapping the previous two rules. Taking the main signal intersection in the bidirectional six lanes as an example, the applicability of exclusive pedestrian signal phase and overpassing facilities were analyzed. The result indicates that the overpassing facilities are supposed to be adopted when the traffic less than 90 s, the proportion of left turn green split time is no less than 50% and the pedestrian volume is no less than 2 700 Ped·（h·m）-1.