基于时间成本的城市街道人行横道间距设置研究

Setting of Crosswalk Spacing in Urban Streets by Time Cost

城市道路路段内的人行横道间距设置过大或过小,均会对行人或机动车造成不利影响。为更加科学地设置路段内的人行横道间距,以城市路段内无信号人行横道为研究对象,在行人和机动车流符合泊松分布前提下,根据交通流车头时距符合负指数分布特点,分析行人和机动车相互穿越的安全间隙,得出行人与机动车的排队聚散规律,推导行人和机动车平均延误计算公式。在此基础上,以行人和机动车的时间成本作为评价指标,运用数学中的极值计算方法,构建基于行人和机动车总延误时间最小时的城市无信号人行横道间距数学模型。实例验证表明模型能有效减少人车总延误,提高人车系统的总体效率。

In order to set the crosswalk spacing in the road section more scientifically, the unsignalized crosswalk in the urban road section is taken as the research object, and the pedestrian and motor vehicle flow is assumed to conform to the Poisson distribution. According to the characteristics that the headway of the traffic flow conforms to the negative exponential distribution, the safety gap between pedestrians and motor vehicles is analyzed, the queuing gathering and dispersion law of travelers and motor vehicles is obtained, and the calculation formula of the average delay of pedestrians and motor vehicles is derived. On this basis, taking the time cost of pedestrians and motor vehicles as the evaluation index and using the extreme value calculation method in mathematics, a mathematical model of urban unsignalized crosswalk spacing based on the minimum total delay time of pedestrians and motor vehicles is constructed. Combined with an example, it is verified that the model can effectively reduce the total delay of people and vehicles and improve the overall efficiency of people and vehicles system. The research conclusion can provide a quantitative method for the setting of pedestrian crossing spacing in urban sections.