基于时空指标的人车冲突等级评价及影响分析

Evaluation of pedestrian-vehicle conflict severity at non-signalized crosswalks by combining time and distance gap data

无信号控制路段人车冲突评估对于实施交通安全策略具有重要意义。采用交通调查和数据分析的方法,通过Tracker软件处理试验视频获取人、车、路3方面数据和15个解释变量信息,并将考虑时空的复合T DI(Time Distance Evaluation Indicator)作为人车冲突评价指标。随后,利用一维K means聚类算法确定边界值,以对人车冲突等级进行划分。建立基于Odered Probit回归分析的人车冲突量化模型,利用Stata软件标定模型参数。结果显示,基于时空指标的人车冲突中,行人“结伴行为”“使用电子设备”“一阶段过街”对冲突等级影响显著,且呈正相关。其中,女性比男性冲突更严重。“过街等待时长”“行人过街速度”与冲突等级呈负相关,“大客(货)车”对冲突等级影响显著(0.4072),且均在95%的置信区间中显著。

The evaluation of pedestrian-vehicle conflict at nonsignal control sections is of great significance for the adoption of traffic safety strategies.This paper used the methods of traffic video recording and field research to obtain experimental data and conduct analysis.The recording traffic video was processed by Tacker software to obtain the data of pedestrians,vehicles and roads,and the information of 15 explanatory variables.The composite T DI(Time-Distance evaluation Indicator)value considering time and distance was used as the evaluation index of the conflict between pedestrians and vehicles.The weight coefficient of the time index and distance index were determined by the AHP method(Analytic Hierarchy Process).Then,the threshold value of T DI value was determined by a onedimensional K means clustering algorithm,the threshold value corresponding to the critical value of different conflict levels and the level of pedestrian-vehicle conflict is divided.Then a quantitative model of pedestrian-vehicle conflict based on the Ordered Probit(OP)regression model was established.On this basis,the impact of pedestrian crossing micro behavior on the severity of pedestrian-vehicle conflict at non-signal controlled sections was further discussed.The model parameters were calibrated using Stata software.A total of 8 indicators have a significant impact on the level of pedestrian-vehicle conflict in the non-signal control section.The results showed that the pedestrian-related variables“partnering behavior”,“using electronic devices”,and“one-stage street crossing”had a significant and positive correlation with the conflict level in the pedestrian-vehicle conflict based on T DI indicators.Women had more serious conflicts than men,and the variables“waiting time”and“pedestrian crossing speed”had a negative correlation with the conflict level,the variable“Large passenger(freight)vehicles”have a significant impact on the level of conflict and the value is prominent(0.4072).The above results were all in the 95%confidence interval.