基于韦布尔分布的行人过街特性模型

行人过街特性对信号配时设计具有重要影响。为说明行人穿越机动车流的过街特性,基于韦布尔分布函数描述了机动车车头时距分布,并得到行人在一次穿越一条车道、多条车道或一个方向三种穿越方式下的穿越概率、平均等待间隔数、平均等待时间和平均延误等特性。利用长春市典型路段调查数据,验证机动车车头时距分布的韦布尔模型;并对各种穿越方式的行人过街特性进行对比分析。结果表明:韦布尔函数描述的机动车车头时距分布与实测分布接近,检验效果在置信度为95%时非常显著;行人单独穿越内、外侧车道的特性差异不大,而同时穿越内、外侧车道的概率明显偏小,且平均等待间隔数和平均延误明显偏大;行人穿越人行横道时逐车道、逐方向和一次穿越的总延误依次增加。基于韦布尔分布的行人过街特性模型能够很好地解释行人过街行为,可以为城市行人交通设施设计和信号优化提供理论依据。

Pedestrian crossing characteristics models based on Weibull distribution

The pedestrian crossing characteristics have an important effect on the signal timing design. The vehicular headway distribution was described by the Weibull function to explain the pedestrian crossing characteristics through the vehicle flow. The crossing probability, the average waiting interval, the average waiting time and the average delay were obtained under conditions when pedestrians cross one-lane or multi-lane once, or with three types of crossing manners in one-direction. Field data from a typical segment in Changchun city were used to validate the Weibull model of vehicle headway. The pedestrian crossing characteristics were compared under different crossing modes. The results indicate that the vehicular headway distributions depicted by the Weibull function approach their observed distributions and the tests are quite notable under 95% confidence; that the difference is not obvious when pedestrians cross the inboard or outboard lane alone, but the probability is less and the average waiting interval and delay are more when pedestrians cross the two lanes simultaneously; and that the total delays progressively increase when pedestrians cross the crosswalk through lane-by-lane, direction-by- direction or at once. The Weibull models of pedestrian crossing characteristics can explain the pedestrian crossing behavior and provide the theoretical basis for urban pedestrian traffic establishment design and signal optimization.