信号交叉口直行非机动车膨胀特性分析与风险评估

Risk Assessment and Expansion Characteristics of Non-motor Vehicle Through Movement at Signalized Intersections

随着信号交叉口的非机动车流量激增,非机动车通过交叉口时的膨胀特性也进一步凸显。针对该现象所带来的冲突问题,在分析非机动车膨胀特性的基础上,提出信号交叉口直行非机动车冲突风险实时评估方法。选取天津市4个典型城市交叉口,通过视频分析软件,获取非机动车的行驶行为数据,分析膨胀特性下直行非机动车行驶行为特征。在此基础上,通过K-means聚类分析将直行非机动车的行驶区域划分为释放区、膨胀区和汇入区这3个区域。构建以直行非机动车不同行驶区域为一级指标,不同区域内的行驶行为特征为二级指标的信号交叉口直行非机动车冲突风险评价体系,提出基于改进熵权法的非机动车冲突风险熵计算方法。以天津市围堤道交叉口为例进行风险评估,结果表明,其冲突风险主要集中于车辆超车与并行行为频发的地带,风险点变化和分布与车辆膨胀过程中风险变化趋势一致,可以为信号交叉口非机动车冲突风险研究提供一定的参考。

With the increase of non-motor vehicles in urban traffic,the expansion characteristics of non-motor vehicles traveling through the intersection are observed more often.This paper focused on the conflicts of vehicle movements at intersections and proposed an assessment method for the conflict risk of non-motor vehicle through movements considering the expansion characteristics.This study selected four typical urban intersections in Tianjin city of China to collect non-motor vehicle driving behavior data through video analysis software and analyzed the driving behavior characteristics while traveling through under expansion conditions.Using the K-means cluster analysis,the driving area was divided into three zones for the through movement of non-motor vehicle:release area,expansion area,and convergence area.A Signalized Intersection Direct Non-Motorized Vehicle Conflict Risk Evaluation System was developed by using different driving areas of direct non-motor vehicles as primary indicators and driving behavioral characteristics in these areas as secondary indicators.A method for calculating the entropy of non-motorized conflict risk was proposed,utilizing an improved entropy weight method.The results from the case study of Weidi Road in Tianjin city show that the conflict risk is mainly concentrated in the zone where vehicles have frequent overtaking and parallel behavior.The change and distribution of the risk points are consistent with the trend of risk change during the process of vehicle expansion,which can provide certain references for the research of non-motor vehicle conflict risk at signalized intersections.