基于排队论的公交站台优化设计

公交站台是城市公共交通的重要组成部分,多线路公交站台进行的优化设计有助于方便车辆有序停靠,满足乘客候车空间需求,提高公交运行效率。通过分析国内外常用的公交站台尺寸设计方法,基于排队论模型引入了公交到达率、服务台数、站台服务率等参数,建立了公交站台尺寸设计模型。研究选择北京市某公交站台作为优化对象对模型进行验证,重新设计了多线路公交站台所需的长宽尺寸,在合理利用空间资源的基础上优化站台的泊位数和尺寸可以有效地减少站台处进站公交车辆排队长度,减少车辆在停靠站的延误,提高公交体系的运营效率。     

兰州快速公交线乘客满意度分析

城市快速公交系统(BRT)是一种高运量、快速的交通服务模式,一直被视为缓解城市交通问题的一剂良药。本文以兰州市快速公交1号线为研究对象,通过设计问卷调查获得其目前的运营情况。针对快速公交系统的舒适性、时效性与经济性等评价因子建立BRT乘客满意度评价指标体系。并借用区间数特征根法(IEM)计算相关指标的各自权重,基于Vague集建立乘客满意度的综合评价模型,最后以对兰州市快速公交1号线为算例验证模型的有效性。结果表明:乘客对BRT在时效性较为满意,而在拥堵状况、服务质量提升、换乘方面需进一步做积极调整。     

公交停靠站通行能力研究

为提高现有公交停靠站的通行能力,文章分析了公交停靠站通行能力的影响因素,从公交停靠时间、清空时间、停靠波动性、交通信号控制四个方面研究公交停靠站的通行能力,并以重庆市公交车作为研究对象,计算了重庆南坪协信城停靠站车辆通过能力。提出为降低停靠时间,需要从减少乘客服务时间出发,对现有站厅的设施配置及功能分区进行完善,既能提高公交运行效率,又能改善站厅的舒适性,一定程度上降低了乘客候车心理时间。研究结果表明改善后的公交停靠站的通行能力有显著提升,车位利用率得到提高,候车环境的舒适性有所改善。     

定制公交多目标鲁棒优化模型与算法

为了确定定制公交在路网中的行驶路径,文章研究了乘客等车时间不确定环境中定制公交行驶路线的鲁棒优化问题:(1)以最小化运营公司的经营费用、最小化乘客的出行时间为优化目标,以车辆的容量限制、乘客的上、下车时间窗、不确定的乘客等车时间等为约束条件,建立了定制公交多目标鲁棒优化模型;(2)采用改进的NSGA-Ⅱ算法(Nondominated Sorting Genetic AlgorithmⅡ)进行求解,用基于未到达交通节点顺序的自然数编码方法进行编码,以锦标赛选择策略进行选择操作以及采用均匀变异方式进行变异操作;(3)选取兰州市局部路网进行案例研究。研究结果表明,运用本文建立的定制公交多目标鲁棒优化模型及求解算法,能快速得到满足优化目标的行驶路径。选用合理的行驶路线能够节约乘客的出行成本,增加运营公司的收益。     

公交电子向标应用猜想

公交车乘客信息服务不到位会怎样?坐错车次或者坐错方向,上下车缓慢、乘客与司乘人员纠纷增加,车辆停靠时间长,站点车辆排队,加重交通拥堵。这些都会造成社会不和谐和资源浪费。新型公交电子向标的发明应用能否改善这一状况呢?     

城市客运

广州快速公交正式运营 2月20日，广州快速公交正式运营，票价统一为2元。广州市交委的统计数据显示，自从2月10日开通试运营以来，中山大道BRT公交系统日均客流量超过40万人次。根据市民反馈的意见，广外IBRT管理公司在春节期间对站点进行了整改。在每个站台的小灯箱都可以看到新安装的标识牌和下一个站点的指引。道路上也有其他车辆全天候一律不得驶入专用车道的标识。     

公交持卡乘客下车站点推导方法研究及验证

本文通过分析公交持卡乘客的出行数据,挖掘乘客的出行规律,改进基于出行链理论的下车站点推导方法,并建立、检索站点邻域集以提升下车站点的推导效率。借助攀枝花市特殊的自动收费系统,利用分段计费线路的下车数据验证了方法的有效性,结果表明下车站点的推导结果具有较高的精度。同时探究了最大步行距离阈值对推导结果的影响,给出不同场景下的应用建议。此外研究分析了不同线路、不同群体的推导效果,对其内在原因做出解释,提供了模型方法的改进方向。研究结果有助于分析乘客的公交出行行为,支撑辅助型公交的需求分析和布设,提升公交服务水平。     

公交站台尾气回收系统设计研究

当前城市雾霾问题日益严重,大气污染问题尚未得到有效解决,汽车尾气排放是造成城市大气污染主要原因之一,特别是重型车中的柴油公交车在怠速、低速、加速启动以及减速过程中产生的尾气排放量是正常速度行驶过程中的2倍以上,车辆在怠速、低速、加速启动、以及减速过程中车辆自身所带的尾气处理装置未能有效的运行,对尾气的处理效果并不理想。本文对公交车站台的外观设计进行考察研究,预期利用公交站台与道路平面的高度差,设计一套公交站台尾气回收装置,将其安置在公交站台中,将公交车在站台停靠时产生的尾气回收处理后,达到可排放标准再排放到大气中,从而达到保护城市大气环境的作用。     

快速公交十年纪:开启中国“大交通”时代

<正>"2005年12月,北京开通全国第"一条快速公交线,实现历史上零的突破。到2015年6月,我国有24个城市开通运营快速公交线路197条,日运送乘客400多万人次。十年漫漫发展路,如今随着我国"优先发展公共交通"相关国策的实施,BRT公交系统建设正阔步向前,为我国的大交通蓝图添柴助力。"智能站台、专有路权、舒适环境,当一辆辆满载乘客的快速公交车,平稳穿梭在城市专用车道上时,不仅是一道靓丽的流动风景线,还将一座城市的活力与生机体现得淋漓尽致。自北京于2005年12月31日开通全国第一条快速公交以来,全国各地有条件的城市正在逐一开通运营,如今已整整发展     

走近BRT系统及公交优先技术

发展公共交通是解决城市交通拥堵的根本出路,快速公交是公共交通的一种重要组成部分,能够在一定程度上缓解拥堵,它具有容量大、运力高、速度快、舒适方便、信息快捷、资金投入少、建设周期短、可靠性高、安全性高、污染少、耗能低等优点。公交优先技术是快速公交的关键技术,它可以减少交叉口BRT车辆的延误,为BRT车辆的快速运行提供技术保障。在我国,快速公交系统自2005年开始发展,并呈现出快速增长的趋势。2005     

A simulation‐based reliability assessment approach for congested transit network

This paper is an attempt to develop a generic simulation‐based approach to assess transit service reliability, taking into account interaction between network performance and passengers' route choice behaviour. Three types of reliability, say, system wide travel time reliability, schedule reliability and direct boarding waiting‐time reliability are defined from perspectives of the community or transit administration, the operator and passengers. A Monte Carlo simulation approach with a stochastic user equilibrium transit assignment model embedded is proposed to quantify these three reliability measures of transit service. A simple transit network with a bus rapid transit (BRT) corridor is analysed as a case study where the impacts of BRT components on transit service reliability are evaluated preliminarily.     

Optimization of headways with stop‐skipping control: a case study of bus rapid transit system

Bus rapid transit system is designed to provide high‐quality and cost‐efficient passenger transportation services. In order to achieve this design objective, effective scheduling strategies are required. This research aims at improving the operation efficiency and service quality of a BRT system through integrated optimization of its service headways and stop‐skipping strategy. Based on cost analysis for both passengers and operation agencies, an optimization model is established. A genetic algorithms based algorithm and an application‐oriented solution method are developed. Beijing BRT Line 2 has been chosen as a case study, and the effectiveness of the optimal headways with stop‐skipping services under different demand levels has been analyzed. The results has shown that, at a certain demand level, the proposed operating strategy can be most advantageous for passengers with an accepted increase of operating costs, under which the optimum headway is between 3.5 and 5.5 min for stop‐skipping services during the morning peak hour depending on the demand with the provision of stop‐skipping services. The effectiveness of the optimal headways with stop‐skipping services is compared with those of existing headways and optimal headways without stop‐skipping services. The results show that operating strategies under the optimal headways with stop‐skipping services outperforms the other two operating strategies with respect to total costs and in‐vehicle time for passengers. Copyright © 2014 John Wiley & Sons, Ltd.     

A model of stoppings on urban bus routes

The amount of time required to pick up and discharge passengers is an important issue in the planning and modeling of urban bus systems. Several past studies have employed models of this component of bus travel time which are based, in part, on a model of the number of stoppings the bus makes to pick up or discharge passengers. Most past versions of this model have assumed that expected demand does not vary from stop to stop or from trip to trip, but that the number of passengers demanding service at any given stop during any given trip follows a Poisson distribution. An alternative model is derived, based on the assumption that expected demand varies among stops and times of day but is fixed from day to day at any given stop and time of day. Boarding and alighting survey data are used to verify that the “average-demand” Poisson model consistently overestimates the number of stoppings and to calibrate an approximate version of the alternative model. A stop-spacing optimization model previously developed by Kikuchi and Vuchic is reevaluated using the alternative stopping model in place of the average demand model used in the original version. The results are found to be considerably different, thus indicating that transit route optimization models are sensitive to the way in which stopping processes are modeled.     

Bus rapid transit systems: a comparative assessment

There is renewed interest in many developing and developed countries in finding ways of providing efficient and effective public transport that does not come with a high price tag. An increasing number of nations are asking the question—what type of public transport system can deliver value for money? Although light rail has often been promoted as a popular ‘solution’, there has been progressively emerging an attractive alternative in the form of bus rapid transit (BRT). BRT is a system operating on its own right-of-way either as a full BRT with high quality interchanges, integrated smart card fare payment and efficient throughput of passengers alighting and boarding at bus stations; or as a system with some amount of dedicated right-of-way (light BRT) and lesser integration of service and fares. The notion that buses essentially operate in a constrained service environment under a mixed traffic regime and that trains have privileged dedicated right-of-way, is no longer the only sustainable and valid proposition. This paper evaluates the status of 44 BRT systems in operation throughout the world as a way of identifying the capability of moving substantial numbers of passengers, using infrastructure whose costs overall and per kilometre are extremely attractive. When ongoing lifecycle costs (operations and maintenance) are taken into account, the costs of providing high capacity integrated BRT systems are an attractive option in many contexts.     

User perspectives in public transport timetable optimisation

The present paper deals with timetable optimisation from the perspective of minimising the waiting time experienced by passengers when transferring either to or from a bus. Due to its inherent complexity, this bi-level minimisation problem is extremely difficult to solve mathematically, since timetable optimisation is a non-linear non-convex mixed integer problem, with passenger flows defined by the route choice model, whereas the route choice model is a non-linear non-continuous mapping of the timetable. Therefore, a heuristic solution approach is developed in this paper, based on the idea of varying and optimising the offset of the bus lines. Varying the offset for a bus line impacts the waiting time passengers experience at any transfer stop on the bus line.In the bi-level timetable optimisation problem, the lower level is a transit assignment calculation yielding passengers’ route choice. This is used as weight when minimising waiting time by applying a Tabu Search algorithm to adapt the offset values for bus lines. The updated timetable then serves as input in the following transit assignment calculation. The process continues until convergence.The heuristic solution approach was applied on the large-scale public transport network in Denmark. The timetable optimisation approach yielded a yearly reduction in weighted waiting time equivalent to approximately 45 million Danish kroner (9 million USD).     

Value of accessibility to Bogotá's bus rapid transit system

With several successful cases world‐wide, bus rapid transit (BRT) has reemerged as a cost‐effective transportation alternative for urban mobility. Despite the resurgence of BRT, there is a world‐wide paucity of research examining its ability to spur and development. By estimating spatial hedonic price functions, the paper determines the extent to which access to BRT stations in Bogotá, Colombia, currently are capitalized into land values. Results suggest that for every 5 min of additional walking time to a BRT station, the rental price of a property decreases by between 6.8 and 9.3%, after controlling for structural characteristics, neighbourhood attributes and proximity to the BRT corridor. Evaluated at the average walking time to a BRT station, this effect translates into an elasticity of between ??0.16 and ??0.22. Although these estimates cannot be attributable directly to the presence of the BRT system because a cross‐sectional design is used, they suggest that the land market in Bogotá values access to BRT station locations.     

Development of a probabilistic model to optimize disseminated real‐time bus arrival information for pre‐trip passengers

In the advent of Advanced Traveler Information Systems (ATIS), the total wait time of passengers for buses may be reduced by disseminating real‐time bus arrival times for the next or series of buses to pre‐trip passengers through various media (e.g., internet, mobile phones, and personal digital assistants). A probabilistic model is desirable and developed in this study, while realistic distributions of bus and passenger arrivals are considered. The disseminated bus arrival time is optimized by minimizing the total wait time incurred by pre‐trip passengers, and its impact to the total wait time under both late and early bus arrival conditions is studied. Relations between the optimal disseminated bus arrival time and major model parameters, such as the mean and standard deviation of arrival times for buses and pre‐trip passengers, are investigated. Analytical results are presented based on Normal and Lognormal distributions of bus arrivals and Gumbel distribution of pre‐trip passenger arrivals at a designated stop. The developed methodology can be practically applied to any arrival distributions of buses and passengers.     

A model of bus bunching under reliability-based passenger arrival patterns

If bus service departure times are not completely unknown to the passengers, non-uniform passenger arrival patterns can be expected. We propose that passengers decide their arrival time at stops based on a continuous logit model that considers the risk of missing services. Expected passenger waiting times are derived in a bus system that allows also for overtaking between bus services. We then propose an algorithm to derive the dwell time of subsequent buses serving a stop in order to illustrate when bus bunching might occur. We show that non-uniform arrival patterns can significantly influence the bus bunching process. With case studies we find that, even without exogenous delay, bunching can arise when the boarding rate is insufficient given the level of overall demand. Further, in case of exogenous delay, non-uniform arrivals can either worsen or improve the bunching conditions, depending on the level of delay. We conclude that therefore such effects should be considered when service control measures are discussed.     

A stochastic optimization model for transit network timetable design to mitigate the randomness of traveling time by adding slack time

Transit network timetabling aims at determining the departure time of each trip of all lines in order to facilitate passengers transferring either to or from a bus. In this paper, we consider a bus timetabling problem with stochastic travel times (BTP-STT). Slack time is added into timetable to mitigate the randomness in bus travel times. We then develop a stochastic integer programming model for the BTP-STT to minimize the total waiting time cost for three types of passengers (i.e., transferring passengers, boarding passengers and through passengers). The mathematical properties of the model are characterized. Due to its computational complexity, a genetic algorithm with local search (GALS) is designed to solve our proposed model (OPM). The numerical results based on a small bus network show that the timetable obtained from OPM reduces the total waiting time cost by an average of 9.5%, when it is tested in different scenarios. OPM is relatively effective if the ratio of the number of through passengers to the number of transferring passengers is not larger than a threshold (e.g., 10 in our case). In addition, we test different scale instances randomly generated in a practical setting to further verify the effectiveness of OPM and GALS. We also find that adding slack time into timetable greatly benefits transferring passengers by reducing the rate of transferring failure.     

Ridership estimation procedure for a transit corridor with new bus rapid transit service

Ridership estimation is a critical step in the planning of a new transit route or change in service. Very often, when a new transit route is introduced, the existing routes will be modified, vehicle capacities changed, or service headways adjusted. This has made ridership forecasts for the new, existing, and modified routes challenging. This paper proposes and demonstrates a procedure that forecasts the ridership of all transit routes along a corridor when a new bus rapid transit (BRT) service is introduced and existing regular bus services are adjusted. The procedure uses demographic data along the corridor, a recent origin–destination survey data, and new and existing transit service features as inputs. It consists of two stages of transit assignment. In the first stage, a transit assignment is performed with the existing transit demand on the proposed BRT and existing bus routes, so that adjustments to the existing bus services can be identified. This transit assignment is performed iteratively until there is no adjustment in transit services. In the second stage, the transit assignment is carried out with the new BRT and adjusted regular bus services, but incorporates a potential growth in ridership because of the new BRT service. The final outputs of the procedure are ridership for all routes and route segments, boarding and alighting volumes at all stops, and a stop‐by‐stop trip matrix. The proposed ridership estimation procedure is applicable to a new BRT route with and without competing regular bus routes and with BRT vehicles traveling in dedicated lanes or in mixed traffic. The application of the proposed procedure is demonstrated via a case study along the Alameda Corridor in El Paso, Texas. Copyright © 2015 John Wiley & Sons, Ltd.