城市道路间断流行程时间双峰分布

在传统行程时间单一概率分布研究基础上,提出了城市间断流行程时间概率分布模型.以正态分布和对数正态分布为典型分布,提出了6种不同的双峰概率分布函数,并利用最小二乘法和Frank-Wolfe算法进行建模和参数拟合.研究结果表明,双峰概率分布函数能够很好地拟合并反映城市道路间断流行程时间概率分布特征,突显其与连续流单一概率分布之间的差异性.研究结果为城市路网路径选择问题提供新的路段阻抗确定方法,也能够为交通分配提供新的路段行程时间概率函数.

Urban Road Interrupted Flow Travel Time Bimodal Distribution

Urban interrupted flow travel time probability distribution models are presented based on conventional travel time unimodal distribution. Six types of bimodal probability distributions which apply normal distribution and lognormal distribution as typical distribution are modeled. The parameters of those models are calibrated by Least Square (LS) and Frank-Wolfe algorithm. The study results demonstrate that bimodal distributions, compared with unimodal distribution, can fit the real data better and highlight the features of interrupted flow. The research contributions can provide a update link cost definitions for path finding in urban network. Meanwhile, the update link travel time probabilistic function can be studied for traffic assignment based on these contributions.