城市轨道交通车站客流承载力研究

在城市轨道交通近期建设规划工作中，需要对重点枢纽或片区近期所需的轨道交通线路和车站数量开展研究并决策线路是否纳入近期建设，为此有必要对城市轨道交通车站客流的合理承载力进行研究。本文首先研究全国已运营的客流量排名靠前的换乘枢纽车站以及已经达到饱和状态而采取限流措施的非换乘车站的实际客流数据，给出各类车站实际运营的承载能力，分析乘客进站各个步骤的理论通行能力以及限制车站客流承载力的瓶颈点。据此提出非换乘站和换乘车站合理的客流承载力的建议值，并提出提升车站客流承载力的建议措施。     

网络化运营模式下城市轨道交通客流分布特性

本文从网络化运营角度,以实际运营网络客流数据为基础,对城市轨道交通客流时间和空间分布特性进行了综合分析。时间分布上主要分析了日客流、周客流、月客流和年客流四个层面的客流特性,空间分布上主要采用了全网客流、高峰断面方向、进出站方向等指标来分析客流分布不均衡性。     

国铁与城市轨道交通过轨运营客流适用性研究

国铁与城市轨道交通线路间的过轨运营可减少乘客换乘,降低换乘站运营组织压力,改善轨道交通运营服务质量和安全性;但将导致土建投资成本增加。本文针对以上特性,提出了国铁与城市轨道交通过轨运营下社会总效用的计算方法。案例结果表明:过轨运营下,乘客出行成本减少的幅度大于投资成本增加的幅度,社会总效用为+19.7亿元,说明适合采用过轨运营。根据过轨运营效果的影响大小排序,分别为乘客平均换乘时间、客流增长率和换乘客流比例。同时,换乘客流比例越大、客流年增长率越大,乘客平均换乘时间越长时,过轨运营越合适。     

基于客流需求的城市轨道交通换乘站“人—车—站”协调研究

随着全国各大城市轨道交通加速成网,快速增长的客流带来了换乘车站换乘通道内客流疏散不及时、行人换乘效率和安全性降低以及车站服务水平下降等问题。通过分析列车运输能力、车站运营设施通过能力,建立列车输送与车站运营设施(站台、通道)的能力匹配关系。基于客流需求,研究城市轨道交通换乘站"人—车—站"的动态平衡条件。以重庆市轨道交通两路口站为例,依据列车开行方案、上下行楼扶梯设置、站台设置、以及相关客流数据等调研资料,通过计算、比较分析提出基于远期客流需求下,两路口站站台层换乘设施及站台的合理优化建议,为车站运营服务水平的提高提供参考。     

基于注意力机制和时空卷积网络的客流预测方法

客流预测方法可以帮助城市轨道交通运营部门根据客流动态变化调配列车资源,是实现精准列车动态控制的基础。研究提出基于注意力机制和时空卷积网络模型的客流预测方法,融合不同功能的网络单元,使得网络可同时捕获客流数据的时间相关性、空间相关性和时空相关性,并采用注意力机制以提高模型预测的准确性,能够同时实现城市轨道交通多站客流的动态预测。基于北京地铁的实际客流数据对该方法和模型进行数值试验,结果表明该模型性能优于其他基线模型。     

基于熵权-Topsis的市域铁路与城市轨道交通贯通模式选择研究

市域铁路与城市轨道交通贯通运营能够充分发挥轨道交通整体效益，降低换乘站压力，提升旅客服务水平。针对市域铁路与城市轨道交通贯通运营形式，本文提出城轨单向贯通、市域单向贯通以及双向贯通三种贯通运营模式并分析。考虑线网性能、服务水平、投资成本、运营组织四种影响因素，基于熵权-Topsis法，建立多时段市域铁路与城市轨道交通贯通运营模式综合评价模型。最后以重庆市市域铁路江跳线与轨道交通五号线为案例，利用三种不同分布特征的客流进行研究，综合得出优选模式为市域单向贯通模式，与实际情况一致，验证了模型的准确性，为多种制式轨道交通贯通运营研究和发展提供理论参考。     

城市轨道交通客流强度及其基本特征分析

本文结合国内外部分城市轨道交通客流强度数据,分析了不同城市轨道交通线网以及不同类型轨道交通线路客流强度的基本特征,从线路空间与网络演变角度剖析了线路客流强度演变的内涵,提出了改善城市轨道交通客流预测工作的建议。     

基于AFC数据的城市轨道交通OD客流动态预测

路网客流实时状态是城市轨道交通系统进行日常运营及关键决策的重要基础，针对目前城市轨道交通客流预测中站点层次预测方法较成熟，而客流分布预测较少的情况，提出基于时序神经网络的量测方程OD客流动态预测方法。利用地铁AFC数据，确定时序神经网络预测的最优数据粒度为15mins和最优时间序列阶数为4，以此构建时序神经网络框架，对站点进站量进行预测；对于站点进站客流与OD客流间的时空关联性，主要体现在进站客流的不同去向以及相同去向下不同的到达时间，建立量测方程反应这一联系，将进站客流转化为OD客流，并以成都地铁为例，对路网条件下不同分布特征OD客流进行预测验证，加权相对误差为14.08%，验证了模型的有效性。     

后疫情时期城市轨道交通客流特征与韧性探讨

在新冠疫情防范常态化的后疫情阶段，城市轨道交通系统频繁受到疫情的影响，提高城市轨道交通系统韧性具有重要意义。本文结合上海市轨道交通疫情及后疫情期间客流量数据，通过使用LSTM模型量化疫情对城市轨道交通系统的影响，验证了城市相关管控策略对轨道系统韧性具有明显影响，提供合理的管控策略对提高城市交通系统韧性具有重要意义。本文结合城市交通韧性理论和交通系统在疫情期间各阶段状态，提出了城市轨道交通韧性治理的相关对策及建议，为疫情防范常态化阶段提高城市轨道交通韧性和精准管控提供参考。     

基于广义费用的城市轨道交通客流分配

为了更加客观全面地反映城市轨道交通出行者决策行为，提升城市轨道交通客流预测准确性，缓解线路运营面临的高峰时段客流拥挤现象，从出行广义费用角度出发，开展城市轨道交通客流分配研究。综合考虑票价、出行时间、舒适度、准时性等因素，构建了城市轨道交通乘客出行广义费用计算模型；以北京地铁5号线为例，将广义费用作为出行阻抗引入客流分配之中，构建了基于广义费用的随机用户平衡条件下的城市轨道交通客流分配模型，并提出了嵌套Logit模型的迭代加权法用以求解模型；基于分配模型及算法，对不同票价和列车容量条件下的城市轨道交通客流分配结果进行了对比分析。结果表明，基于广义费用的城市轨道交通客流分配模型能够实现对轨道交通流量的有效预测，可对各类缓解高峰时段拥挤措施的实施效果进行评估，辅助城市轨道交通领域相关决策。     

上海轨道交通网络化客流特征及规律初探

结合上海轨道交通在实现网络化运营后出现的一些新特征，介绍了客流变化的新动向和新情况，同时，对于在网络运营中，如何把握运营规律、挖掘客流潜力、提升客流强度、提高投资回报等进行了研究和分析，可供在建轨道交通的其他城市借鉴。     

What determines rail transit passenger volume? Implications for transit oriented development planning

Transit oriented development (TOD) has been an important topic for urban transportation planning research and practice. This paper is aimed at empirically examining the effect of rail transit station-based TOD on daily station passenger volume. Using integrated circuit (IC) card data on metro passenger volumes and cellular signaling data on the spatial distribution of human activities in Shanghai, the research identifies variations in ridership among rail transit stations. Then, regression analysis is performed using passenger volume in each station as the dependent variable. Explanatory variables include station area employment and population, residents’ commuting distances, metro network accessibility, status as interchange station, and coupling with commercial activity centers. The main findings are: (1) Passenger volume is positively associated with employment density and residents’ commuting distance around station; (2) stations with earlier opening dates and serving as transfer nodes tend to have positive association with passenger volumes; (3) metro stations better integrated with nearby commercial development tend to have larger passenger volumes. Several implications are drawn for TOD planning: (1) TOD planning should be integrated with rail transit network planning; (2) location of metro stations should be coupled with commercial development; (3) high employment densities should be especially encouraged as a key TOD feature; and (4) interchange stations should be more strategically positioned in the planning for rail transit network.     

Two-phase stochastic program for transit network design under demand uncertainty

This paper develops a reliability-based formulation for rapid transit network design under demand uncertainty. We use the notion of service reliability to confine the stochastic demand into a bounded uncertainty set that the rapid transit network is designed to cover. To evaluate the outcome of the service reliability chosen, flexible services are introduced to carry the demand overflow that exceeds the capacity of the rapid transit network such designed. A two-phase stochastic program is formulated, in which the transit line alignments and frequencies are determined in phase 1 for a specified level of service reliability; whereas in phase 2, flexible services are determined depending on the demand realization to capture the cost of demand overflow. Then the service reliability is optimized to minimize the combined rapid transit network cost obtained in phase 1, and the flexible services cost and passenger cost obtained in phase 2. The transit line alignments and passenger flows are studied under the principles of system optimal (SO) and user equilibrium (UE). We then develop a two-phase solution algorithm that combines the gradient method and neighborhood search and apply it to a series of networks. The results demonstrate the advantages of utilizing the two-phase formulation to determine the service reliability as compared with the traditional robust formulation that pre-specifies a robustness level.     

A bi‐level programming approach — Optimal transit fare under line capacity constraints

The fare of a transit line is one of the important decision variables for transit network design. It has been advocated as an efficient means of coordinating the transit passenger flows and of alleviating congestion in the transit network. This paper shows how transit fare can be optimized so as to balance the passenger flow on the transit network and to reduce the overload delays of passengers at transit stops. A bi‐level programming method is developed to optimize the transit fare under line capacity constraints. The upper‐level problem seeks to minimize the total network travel time, while the lower‐level problem is a stochastic user equilibrium transit assignment model with line capacity constraints. A heuristic solution algorithm based on sensitivity analysis is proposed. Numerical example is used to illustrate the application of the proposed model and solution algorithm.     

Secrets of success: assessing the large increases in transit ridership achieved by Houston and San Diego transit providers

This paper summarizes and updates the findings from an earlier study by the same authors of transit systems in Houston (all bus) and San Diego (bus and light rail). Both systems achieved unusually large increases in transit ridership during a period in which most transit systems in other metropolitan areas were experiencing large losses. Based on ridership models estimated using cross section and time series data, the paper quantifies the relative contributions of policy variables and factors beyond the control of transit operators on ridership growth. It is found that large ridership increases in both areas are caused principally by large service increases and fare reductions, as well as metropolitan employment and population growth. In addition, the paper provides careful estimates of total and operating costs per passenger boarding and per passenger mile for Houston's bus operator and San Diego's bus and light rail operators. These estimates suggest that the bus systems are more cost-effective than the light rail system on the basis of total costs. Finally, the paper carries out a series of policy simulations to analyze the effects of transit funding levels and metropolitan development patterns on transit ridership and farebox recovery ratio.     

Equity-oriented skip-stopping schedule optimization in an oversaturated urban rail transit network

In this study, we focus on improving system-wide equity performance in an oversaturated urban rail transit network based on multi-commodity flow formulation. From the system perspective, an urban rail transit network is a distributed system, where a set of resources (i.e., train capacity) is shared by a number of users (i.e., passengers), and equitable individuals and groups should receive equal shares of resources. However, when oversaturation occurs in an urban rail transit network during peak hours, passengers waiting at different stations may receive varying shares of train capacity leading to the inequity problem under train all-stopping pattern. Train skip-stopping pattern is an effective operational approach, which holds back some passengers at stations and re-routes their journeys in the time dimension based on the available capacity of each train. In this study, the inequity problem in an oversaturated urban rail transit network is analyzed using a multi-commodity flow modeling framework. In detail, first, discretized states, corresponding to the number of missed trains for passengers, are constructed in a space-time-state three-dimensional network, so that the system-wide equity performance can be viewed as a distribution of all passengers in different states. Different from existing flow-based optimization models, we formulate individual passenger and train stopping pattern as commodity and network structure in the multi-commodity flow-modeling framework, respectively. Then, we aim to find an optimal commodity flow and well-designed network structure through the proposed multi-commodity flow model and simultaneously achieve the equitable distribution of all passengers and the optimal train skip-stopping pattern. To quickly solve the proposed model and find an optimal train skip-stopping pattern with preferable system-wide equity performance, the proposed linear programming model can be effectively decomposed to a least-cost sub-problem with positive arc costs for each individual passenger and a least-cost sub-problem with negative arc costs for each individual train under a Lagrangian relaxation framework. For application and implementation, the proposed train skip-stopping optimization model is applied to a simple case and a real-world case based on Batong Line in the Beijing Subway Network. The simple case demonstrates that our proposed Lagrangian relaxation framework can obtain the approximate optimal solution with a small-gap lower bound and a lot of computing time saved compared with CPLEX solver. The real-world case based on Batong Line in the Beijing Subway Network compares the equity and efficiency indices under the operational approach of train skip-stopping pattern with those under the train all-stopping pattern to state the advantage of the train skip-stopping operational approach.     

Long-term planning for ring-radial urban rail transit networks

Extensive work exists on regular rail network planning. However, few studies exist on the planning and design of ring-radial rail transit systems. With more ring transit lines being planned and built in Asia, Europe and the America's, a detailed study on ring transit lines is timely. An analytical model to find the optimal number of radial lines in a city for any demand distribution is first introduced. Secondly, passenger route choice for different rail networks is analyzed, for a many-to-many Origin-Destination (OD) demand distribution, based on a total travel time cost per passenger basis. The routes considered are: (1) radial lines only; (2) ring line only or radial lines and ring line combined; or (3) direct access to a destination without using the rail system. Mathematica and Matlab are used to code the route choice model. A cost-benefit optimization model to identify the feasibility and optimality of a ring line is proposed. Unlike simulations and agent-based models, this model is shown to be easily transferable to many ring-radial transit networks. The City of Calgary is used as an example to illustrate the applicability of each model. The existing urban rail network and trip distribution are major influencing factors in judging the feasibility and optimal location of the ring line. This study shows the potential net benefit of introducing a ring line by assessing changes in passengers’ costs. The changes in passenger cost parameters, such as ride cost and access cost, are shown to greatly influence the feasibility of a ring line.     

北京市轨道交通房山线功能定位分析研究

轨道交通线路功能定位对确定线路的技术标准、运营模式、系统制式等具有决定作用.房山线作为北京近期建设的轨道交通，其功能定位存在较多不确定因素，是北京线网规划阶段一个尚未完全解决的问题，也是项目可行性研究的难点之一。通过研究各层面关键因素对房山线功能的影响，对其定位进行分析，从而为该线的设计提供参考.     

Transit network design based on travel time reliability

This paper presents a transit network optimization method, in which travel time reliability on road is considered. A robust optimization model, taking into account the stochastic travel time, is formulated to satisfy the demand of passengers and provide reliable transit service. The optimization model aims to maximize the efficiency of passenger trips in the optimized transit network. Tabu search algorithm is defined and implemented to solve the problem. Then, transit network optimization method proposed in this paper is tested with two numerical examples: a simple route and a medium-size network. The results show the proposed method can effectively improve the reliability of a transit network and reduce the travel time of passengers in general.     

Bus Rapid Transit System in Istanbul: A Success Story or Flawed Planning Decision?

Abstract

There is a growing tendency in cities around the world to invest in Bus Rapid Transit (BRT) systems in an attempt to improve the capacity and quality of public transport services. The appeal of BRTs is based on their ability to combine the service level of rail transit systems with the flexibility of buses at relatively lower investment costs, and this was the motivation behind the opening of such a system in the Turkish city of Istanbul in 2007. This system has attracted mixed opinions as to its performance, as while passenger ridership figures are extremely high, proving the effectiveness of the system, there is an argument that the corridor should have been developed with rail technology, and that the BRT is failing to meet the demand. The paper presents a comprehensive analysis of this system, assessing its planning and performance through a comparative analysis of a number of BRTs in the world and Istanbul's metro and tram systems. The analysis confirms the success of the system in terms of passenger statistics, but also highlights a number of problems in certain planning decisions that should be addressed, thus taking the discussion beyond a simplified comparison of bus and rail technologies.