考虑多路段关联的城市干道行程时间可靠性机理解析及建模

Urban arterial travel time is highly dynamic and stochastic due to interrupted flow characteristics. To analyze and evaluate arterial travel time reliability will benefit both traffic flow organization and traveling service. However, most of existing studies, based on empirical distribution fitting, are less transferable and fail to reflect the mechanisms of travel time variability from viewpoint of intersection, link and arterial. In view of intersection delay variability as the key component of travel time reliability, this research project begins from both microscopic and macroscopic level. Firstly, cycle average delay at intersections is modeled by employing cumulative curves and discrete Markov Chains. The impact of stochastic initial queue is taken into account for delay variability analysis. Then, based on delay variability modeling, link travel time distribution is modeled by constructing arrival curves at downstream intersection under signal coordination. Next, for urban arterial, Finite Mixture of Regression Model (FMRM) with varying mixture weights is utilized to relate traffic volume and signal timing parameters to the weights of individual link travel time distributions. Finally, real-time evaluation of arterial travel time reliability is made possible through applying FMRM model to multiple links travel time distribution estimation at dynamic analysis intervals by segmentation clustering. The outcomes of this research project help advance urban network reliability theory, and provide theoretical basis and technical support for sophisticated transportation planning, design and traveling service.

城市干道间断交通流特性决定了行程时间高度动态、随机，掌握其可靠性分布规律对于交通流调控与出行服务改善至关重要。以往研究多专注于经验分布拟合，鲜见从交叉口-路段-干道逐层推进对可靠性影响机理的系统解析，更缺乏考虑多路段关联的干道可靠性评估模型。鉴于交叉口延误是干道行程时间波动的关键因素，本项目拟分别从微观和宏观角度入手，首先对交叉口，采用到达-驶离累积曲线与离散马尔科夫决策过程，建立考虑随机滞留排队影响的延误随机性模型；然后对路段，通过构筑协调相位对下游交叉口到达曲线的物理“偏移”，建立路段行程时间分布模型；进而对干道，采用具有可变权重的FMRM混合分布模型，建模各路段行程时间分布权重与交通流量、信号控制参数的内在关系，从而通过“有机衔接”实现考虑多路段关联的干道行程时间分布估计及可靠性评价。研究成果将在完善路网可靠性理论的同时，为精细化交通规划设计、改善出行服务提供理论依据与技术支撑。

城市干道间断交通流特性决定了行程时间高度动态、随机，掌握其可靠性分布规律对于交通流调控与出行服务改善至关重要。本项目分别从微观和宏观角度入手，首先对路段，通过构筑协调相位对下游交叉口到达曲线的物理“偏移”，建立路段行程时间分布模型；进而对干道，分别采用具有可变权重的FMRM混合分布拟合模型及考虑路段相关性的Copula模型，建模各路段行程时间分布权重与交通流量、信号控制参数的内在关系，从而通过“有机衔接”实现考虑多路段关联的干道行程时间分布估计及可靠性评价。本项目系统研究了城市干道行程时间可靠性的评价指标、分析方法和计算模型，在完善路网可靠性理论的同时，为精细化交通规划与管理、改善出行服务提供理论基础与技术支撑。