信号控制交叉口左转电动自行车交通流特性分析

Characteristics of Left-turn Electric Bicycle Traffic Flow at Signalized Intersections

为深入挖掘信号控制交叉口左转电动自行车交通流安全特性及其相互关系,利用江苏省盐城市建军东路与开放大道平面交叉口提取高峰时间段1514辆左转电动自行车的视频数据,提取了左转电动自行车交通流量、速度、密度3个基本参数并进行统计分析.基于最小二乘法原理构建交通流参数模型,从电动自行车的流量-密度模型、流量-速度模型、速度-密度模型3个方面,分析了平面交叉口左转电动自行车的交通流安全特性.研究表明:流量与密度呈现二次函数关系,流量与速度呈幂函数关系,速度与密度呈对数函数关系,3种模型回归方程变量之间存在的函数关系显著,且回归系数具有显著意义;电动自行车驶入交叉口过程可划分为驶入启动期、膨胀加速期、跟随驶离期3个时期,膨胀加速期相比于驶入启动期、跟随驶离期的交通冲突和事故的可能性更大.

In order to better understand the safety characteristics of left turning electric bicycles at signalized intersections,we obtained the data of 1514 left turning electric bicycles from the intersection of Jianjun East Road and Kaifang Road in Yancheng City during peak hours,and analyzed the three basic parameters of left turning electric bicycles:traffic flow,speed and density.The traffic flow models were constructed based on the principle of least square method.Traffic flow characteristics of left turning electric bicycles at intersections were systematically and comprehensively analyzed from three aspects:the flow-density model,flow-speed model and speed-density model.The research shows that the flow-density model presents a quadratic function relationship,the flow-speed model presents a power function relationship,and the density-speed model presents a logarithmic function relationship.The functional relationship between variables in the regression equation of the three models is significant,and the regression coefficient is statistically significant.The process of electric bicycles entering the intersection is divided into three periods:the starting period,the acceleration period,and the following departure period.Compared with the starting period and the following departure period,the acceleration period is more likely to cause traffic conflicts and crashes.