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常规公交网络运行可靠性多层次评价模型与算法
Multi-level Models and Algorithms for Evaluating Operational Reliability of Bus Network
【作者】 宋晓梅;
【导师】 于雷;
【作者基本信息】 北京交通大学 , 交通运输规划与管理, 2010, 博士
【摘要】 公共交通运行可靠性是关系到公交服务质量、决定乘客出行方式选择的重要因素,研究公交运行可靠性问题对于掌握公交运行规律,提高公交运行效率有着至关重要的作用。目前对公交运行可靠性研究存在评价角度侧重于乘客、评价指标依赖于行车时刻表、评价模型多限于微观局部站点以及少数线路理论探讨等问题。本文在分析国内外公交系统可靠性评价发展历程的基础上,对评价中反映公交运行可靠性的多个指标和基于多指标的综合评价模型进行综述,并根据常规公交运行特性,对公交运行可靠性进行更加全面、明确的定义,分别构建不依赖时刻表的站点、线路和网络的多层次公交运行可靠性评价模型与算法。本文的主要研究成果包括:1.对区间运行时间进行分布拟合,建立了基于对数正态分布的区间运行时间模型,在此基础上,利用数理统计法分析不同服务水平下的单位距离区间运行时间阈值,建立基于可接受公交服务水平下的期望运行时间可靠性模型。2.对构成站点停靠时间的开门时间、乘客上下车时间和关门时间进行深入分析,研究开、关门时间和乘客上下车时间的分布规律,通过曲线拟合和参数估计、假设检验,得到开关门时间服从泊松分布、人均上下车时间服从对数正态分布、上下车人数服从负二项分布的结论,并分别利用聚类分析法和数理统计法确定不同公交服务水平下的时间阈值范围,建立可接受公交运行服务水平下,基于期望停靠时间的站点停靠时间可靠性评价模型。3.选取区段公交运行时间可靠性和到达间隔可靠性指标作为中观层次公交运行可靠性评价指标,并以各指标的变异系数倒数值为权重,建立中观层次公交运行可靠性评价模型。区段公交运行时间是区段内所有站点停靠时间和区间运行时间的总和,期望运行时间也是可接受的站点停靠时间和区间运行时间之和;利用到区间隔可靠性具有无后效性的特点,运用马尔科夫链的.C-K方程确定状态转移矩阵,建立到区间隔可靠性评价模型。4.以区段公交运行可靠性为评价基础,根据各区段在网络运行可靠性中发挥的作用,利用各区段所有站点上下车乘客总量为权重,建立宏观层面的公交网络和区域运行可靠性评价模型。
【Abstract】 The operational reliability of bus transit system is an important indicator in evaluating the quality of bus services, which plays a critical role in influencing passengers’choice of mode for travel. The study on the bus operational reliability is of much significance for capturing the operational characteristics of buses and improving the operational efficiency of the bus transit system. At present, however, the study on the bus operational reliability has suffered a number of shortcomings such as almost from passenger’s view, only focusing on problems with known bus schedule, as well as evaluation models for limited stops and pure theoretical study on bus routes. This dissertation is intended to provide a more comprehensive and clearer definition of the bus operation reliability after synthesizing development course of bus system reliability and existing evaluation indicators which reflect bus operational reliability, models based on several indicators and bus operational characteristic. It set up multi-level bus operational reliability models and algorithms, which lie on stations, bus lines and bus networks but independent on bus schedules.The main contributions of the dissertation include:1. The distribution fitting of travel times between adjacent stations is developed, resulting that the bus travel time between stops follows the lognormal distribution. Then, the travel time thresholds for different bus service levels are determined using the mathematical statistics methods. Further, a model for the expected travel time reliability is developed on the basis of the accepted bus service levels.2. A thorough analysis of the stop time composition at bus stops is conducted, which contains intervals between the arriving and door open times, the door close and open timse, and the door close and departing times. The distributions of these three intervals are examined. It is shown that the intervals between the arriving time and door open time follows the Poisson distribution, the average time for the passenger to get on or off the bus follows the lognormal distribution, and the number of passengers getting on or off the bus follows the negative binomial distribution. The range of time thresholds under different bus service levels is determined using the cluster analysis and mathematical statistics methods. Finally, the stop time reliability models are developed based on the expected stop times.3. Two indicators are selected for evaluating the meso-level bus operational reliability, which are the sectional travel time reliability and the arriving headway reliability. Then, a meso-level bus operational reliability model is developed using the inverse of the coefficient of variations of these two indicators as the weights. The sectional travel time is the sume of the stop time at stations and the travel time between adjacent stations. So the sectional travel time reliability can be calculated by the probability when the travel time is equal to or less than the expected travel time threshold. The arriving headway reliability only depends on the current state, the stop time reliability and the travel time reliability of later state, which is the characteristic of Markov theory. Finally, the arrival headway reliability can be calculated using the C-K state transition equation.4. A macro-level network and regional bus operational reliability is established using the sectional bus operational reliability as the basis, based on the role that each secion plays in the network, and using the boarding and alighting passengers as the weights.