城市交通中利用Gram-Charlier分布估计行程时间可靠性

行程时间可靠性近年来成为交通领域重点关注的问题,但现有方法在反映当前行程时间的尖峰厚尾特征方面已表现出与实际情况的较大差异,因此本文针对这一弱点,结合数据收集的难易,设计了一种新颖的栅格行程时间预测方法,可以全面考虑车辆的行驶和等待时间,然后引入了可以反映更多行程时间信息的Gram-Charlier分布函数,作为行程时间可靠性的研究手段,同时对分布参数给出了两种计算方法.仿真结果表明,本文提出的方法能很好体现当前城市交通行程时间的易变性特点.

Estimating Travel Time Reliability in Urban Transportation Using Gram-Charlier Distribution

The deteriorative traffic condition in many cities significantly augments travel cost, and hence resulting in so-called fat tail effect.This paper aims at depicting such phenomenon by employing such concept as travel time reliability(TTR) to recapitulate the variational character.Firstly, a no vel metho d to predict travel time, i.e.grid method, is designedfor the sake of integrating driving time and queuing time.And then, Gram-Charlier as a powerful probability tool is applied to describe the extrusive character of TTR based on its four parameters.Two approaches are discussed to assist derive those parameters in closed form.Finally, a simulation result illustrates that the method works, and further research is indicated as well.