Analysis of the influence of occupation rate of public transit vehicles on mixing traffic flow in a two-lane system

Based on the existing classical cellular automaton model of traffic flow, a cellular automaton traffic model with different-maximum-speed vehicles mixed on a single lane is proposed, in which public transit and harbour-shaped bus stops are taken into consideration. Parameters such as length of cellular automaton, operation speed and random slow mechanism are re-demarcated. A harbour-shaped bus stop is set up and the vehicle changing lane regulation is changed. Through computer simulation, the influence of occupation rate of public transit vehicles on mixed traffic flow and traffic capacity is analysed. The results show that a public transport system can ease urban traffic congestion but creates new jams at the same time, and that the influence of occupation rate of public transit vehicles on traffic capacity is considerable. To develop urban traffic, attention should be paid to the occupation rate of public transit vehicles and traffic development in a haphazard way should be strictly avoided.

Morphology of single inhalable particle inside public transit biodiesel fueled bus

In an urban-transit bus, fueled by biodiesel in Toledo, Ohio, single inhalable particle samples in October 2008 were collected and detected by scanning electron microscopy and energy dispersive X-ray spectrometry （SEM/EDS）. Particle size analysis found bimodal distribution at 0.2 and 0.5 μm. The particle morphology was characterized by 14 different shape clusters： square, pentagon, hexagon, heptagon, octagon, nonagon, decagon, agglomerate, sphere, triangle, oblong, strip, line or stick, and unknown, by quantitative order. The square particles were common in the samples. Round and triangle particles are more, and pentagon, hexagon, heptagon, octagon, nonagon, decagon, strip, line or sticks are less. Agglomerate particles were found in abundance. The surface of most particles was coarse with a fractal edge that can provide a suitable chemical reaction bed in the polluted atmospheric environment. The three sorts of surface patterns of squares were smooth, semi-smooth, and coarse. The three sorts of square surface patterns represented the morphological characteristics of single inhalable particles in the air inside the bus in Toledo. The size and shape distribution results were compared to those obtained for a bus using ultra low sulfur diesel.

Two Network Structure Indicators for Conventional Public Transit

The significance of network structure indicators for the planning and management of conventional public transit is widely acknowledged.In order to improve and enrich the conventional public transit assessment system,two network structure indicators are proposed.Firstly,according to the obvious defects lying in the traditional no-linear coefficient,the realistic no-linear coefficient γRNL,a modified no-linear coefficient indicator,is put forward,which takes into account the effects of barriers in a city.Secondly,to cover the gap of an indicator which can reflect the coverage homogeneity of a transit network,the length dimension LDis proposed on the basis of Fractal Theory.Finally,a case study is applied to verify the validity and practicability of the two indicators in problem diagnosis using regression analysis.The results validate that γRNLcan evaluate the detour of bus lines more reasonably than the previous no-linear coefficient because it reflects the layout of bus lines,and LDcan represent the rate of change of the network density,adding a new member to the scheme of network structure indicators for public transit.

PM10 and CO Exposure of Hong Kong Population in Public Transit Facilities

Taking public transit facilities (PTFs) is the major transport style in Hong Kong. Human exposure to indoor air pollutants may cause adverse health effects to the passengers. Exposure assessment on air pollutants is important for the control of human diseases caused by indoor air pollution. In this paper, the indoor PM10, CO and CO 2 levels in various PTFs, such as public bus, subway, railway and ferry in Hong Kong, were mea- sured. Combining with the time budget survey of Hong Kong population,the human exposures were calculated through Monte-Carlo simulation.

Public Transit Connectivity Measures and Analysis of Weak Segments

Bus and any other public transit connectivity issues facilitate an understanding of the importance of transit planning in enhancing existing or new transit services. Improving transit connectivity is one of the most vital tasks in transit-operations planning. A poor connection can cause some passengers to stop using the transit service. Service-design criteria always contain postulates to improve routing and scheduling coordination （intra- and inter-agency transfer centers/points and synchronized/timed transfers）. Ostensibly the lack of well-defined connectivity measures precludes the weighing and quantifying of the result of any coordination effort. This work provides an initial methodological framework and concepts for （1） quantifying transit connectivity measures and （2） directions and tools for detecting weak segments in inter-route and inter-modal chains （paths） for possible revisions/changes.

Potential Benefits of Increased Public Transit Ridership in Medium Sized Cities: A Case Study

At the beginning of the twentieth century, the United States was leading in the public transit sector, but following World War II, private automobiles became more affordable and gained popularity. Transportation infrastructure investments that increased road capacity further facilitated the increase in automobile use at the expense of reduced public transit ridership. With the increase of dependency on automobiles and the continuing growth of private automobile ownership and use, various problems became major challenges in big cities of USA. These include traffic congestion, air pollution, road and parking infrastructure costs, energy consumption, traffic safety, fewer mobility options for the non-drivers, and a decline in the image and use of public transit. This study uses a medium sized city, Birmingham as a case study to investigate the potential of public transit to reduce automobile trips and in turn improve the overall performance of the road network by addressing the abovementioned challenges. An agent-based simulation model was developed for the Birmingham metropolitan region using the Multi-agent Transport Simulation (MATSim) platform. Three scenarios were considered with gradually increased transit ridership to identify the benefits of increased public transit. Traffic volume, network average speed, and travel times were used as performance measures for the evaluation of the designated scenarios. Results suggest that modal shifts toward public transit and reduction in travel demand for an automobile can result in improvements in speed and travel time for all users. Therefore, investments for improving transit quality and frequency of service, as well as campaigns to improve the image of public transit and make it a mode of choice for transportation users can increase transit ridership and, in turn, improve network operations, thus are deemed worthy for medium sized cities.

Public Transit Performance Evaluation Using Data Envelopment Analysis and Possibilities of Enhancement

This study evaluates the operational performance of all routes of Sajha Bus Yatayat operating inside Kathmandu valley using Data Envelopment Analysis (DEA) in terms of efficiency and effectiveness score. This approach allows us to access the relative performance of transit system in absence of historical data and research to compare with. To explore the possibility of enhancing the performance, scenarios were created for relatively underperforming routes and long route problem by changing the most important input variable and output variables accordingly with regression model where it was relevant. Partial Least Squares (PLS) regression was used to determine the most influential input variables to the output variables. DEA was conducted to access the performance of all routes under these scenarios. Underperforming routes except the longest route under the first set of scenarios, emerge to be better performing efficiently without considerable negative deviation in effectiveness. The result of second set of scenarios for long route problem suggests that the longest route’s performance can be enhanced significantly upon proper route alignment. Scenarios development and evaluation can help lead transit companies to explore the strategies to facilitate operational performance enhancement.

Improving access to urban parks through public transit optimization

This study establishes an evaluation and optimization framework for the public transit network based on social network analysis and a greedy algorithm,aiming to explore a quantitative approach to improving access to urban parks through public transit optimization.Social network analysis and the ArcGIS platform are used to build a public transit network model within Nanjing Old City and analyze its overall network structure characteristics.The study also focuses on a method to improve the convenience of reaching regional and citylevel parks by public transit by increasing access and connecting points accordingly.A greedy algorithm is introduced to generate an optimized solution for improving public transit accessibility to regional and city-level parks,consequently enhancing their utilization.The major findings include:(1)The greedy algorithm effectively enhances the performance of the public transit network,but its benefits gradually diminish as more stations are added.(2)Strategically adding stations enhances the performance of most public transit access points,creating efficient pathways for other stations to directly reach these access points and enter regional and city-level parks.(3)The optimized public transit network model offers guidance for the planning and layout of regional and city-level parks.The site selection for new parks should prioritize establishing connections with the“hubs”in the public transit network.The proposed optimization of the public transit network in this study is specific to a single type of urban park,but subsequent research could be conducted to extend the optimization of public transit accessibility around more urban public resources.

Measuring positive public transit accessibility using big transit data

Most of the current existing accessibility measures quantify the potential of reaching desirable opportunities across space and time.Nevertheless,these potential measurements only illus-trate the maximum possible accessibility a person can have,which may not accurately measure real-world transit accessibility in urban areas.This paper introduces a novel methodology to measure positive public transit accessibility based on multi-source big public transit data such as Smart Card Data(SCD)and Global Navigation Satellite System trajectory data,which embed rich travel information and real-world spatio-temporal constraints.First,we use multi-source transit data to reconstruct trip chains,which are used to extract popular destinations.A novel transit accessibility measure is defined to account for latent trip information such as mode/route preference,opportunity attraction,and travel impedance that are difficult to capture explicitly via traditional normative measures.Finally,we produce accessibility maps to visualize time-varying and heterogeneous accessibility patterns distributed over the study region.We performed an empirical evaluation on real-world transit data collected in Shenzhen City,China,demonstrating the applicability and effectiveness of the proposed method in mapping positive transit accessibility over large metropolitan areas.The results and findings of the empirical study demonstrate that the proposed positive accessibility measure can better capture travel behavior characteristics and constraints than traditional normative measures.The measure-ment method can be used as a practical high-resolution mapping tool for transit decision makers in evaluating public transit systems,supporting strategic transit planning,and improv-ing daily transit management.

Zero-emission public transit could be a catalyst for decarbonization of the transportation and power sectors

Reaching carbon neutrality will require investment on an unprecedented scale.Here we suggest that there is an underappreciated opportunity to leverage public funds to mobilize private capital in support of these aims.We illustrate the point using examples from public transit.Although the fuelling energy requirements of public fleets represent a small fraction of the eventual total demand across the transportation sector,the predictable and long-term nature of the refuelling profiles can reduce the financing risk.With appropriate coordination across the energy supply chain,near-term investments can be used to support scale-up of wider efforts to decarbonize the transportation sector and electric grid.We present two examples from California-one related to overnight power for battery electric bus charging and the other related to medium-scale supply chains for zero-carbon hydrogen production-to illustrate how this might be achieved.

Simultaneous optimization of transit network and public bicycle station network

The traditional manner to design public transportation system is to sequentially design the transit network and public bicycle network. A new public transportation system design problem that simultaneously considers both bus network design and public bicycle network design is proposed. The chemical reaction optimization(CRO) is designed to solve the problem. A shortcoming of CRO is that, when the two-molecule collisions take place, the molecules are randomly picked from the container.Hence, we improve CRO by employing different mating strategies. The computational results confirm the benefits of the mating strategies. Numerical experiments are conducted on the Sioux-Falls network. A comparison with the traditional sequential modeling framework indicates that the proposed approach has a better performance and is more robust. The practical applicability of the approach is proved by employing a real size network.

Users’ Perception on Operation and Performance of Public Transport Systems in African Developing Countries: The Case of Bus Rapid Transit (BRT) in Dar es Salaam City, Tanzania

Public transport system has been a means of addressing transportation challenges in urban areas, such as traffic congestion, traffic jam and long travel time in cities worldwide. Transportation in Africa is unique in that it has the least developed public transport systems in the world, while also being one of the fastest urbanizing continents. Bus Rapid Transit being one of the public transport systems was introduced in Africa in 2008 as a means to provide solution on urban transportation challenges. Despite of public transport being the main means of transport in African developing countries, there have been a number of challenges that affects efficiency of performance of the system and makes its users uncomfortable. Therefore, the study aimed at exploring the setbacks or challenges associated with operation and performance of the BRT system in the African developing countries and address them. The study employed mixed methods research design that integrates both qualitative and quantitative data collection methods and analysis. The study findings reveal that, there is an improvement on the perspectives of the commuters on public transport after introduction of BRT system. However, some challenges such as long waiting time, passengers overcrowding during peak hours, as well as safety and security can slowly change the perspective of the commuters. Therefore, to address these challenges it is recommended to reduce the long waiting time and improve accessibility by introduction of passenger information displays (bus information system) and automated fare collection system;reduce travel time by introduction of bus priority signal;and improve safety and security by introduction of signage and CCTV Camera within the bus and bus stops.

公众环境参与推动家庭消费的低碳转型效应——基于中国家庭追踪调查的经验证据

基于中国家庭追踪调查(CFPS)数据,探讨公众环境参与对家庭消费低碳转型的作用机制及其影响。结果表明:公众环境参与可以在消费端驱动公众低碳消费选择和在生产端优化用能结构进而推动家庭消费低碳转型,稳健性检验发现推动家庭消费的低碳转型效应呈显著表现。此外,家庭抚养负担比重、地区资源禀赋差异以及政府环境执法力度会对公众环境参与的作用效果产生差异化影响,在抚养负担比重较高家庭、资源型地区以及政府环境执法力度较高地区中公众环境参与对家庭消费低碳转型的推动作用更为显著。最后从拓宽环境治理的公众参与渠道、坚持消费端与生产端双向发力以及确保政策实施精准化等方面提出政策建议,以期为实现“双碳”目标、健全多元共治的现代环境治理体系提供更多经验证据。

洛阳轨道交通站点步行接驳的影响因素研究

通过分析洛阳轨道交通站点的步行接驳影响因素,旨在为提高公共交通吸引力、优化轨道交通系统和促进可持续交通发展提供参考。研究基于GIS分析、实地调研和调查问卷,重点考察了不同类型站点特征、站点设计与布局、客流特征与出行需求及公共交通政策与管理等因素。结果显示,站点周边的功能混合度、人口密度、公共设施和服务质量等因素,以及站点的出入口位置、数量、通达性对步行接驳质量有显著影响。此外,乘客的出行目的、时间分布和交通换乘需求也对步行接驳服务质量产生影响。基于调研结果,建议采取提升步行网络密度、提升步行网络的整体性等措施,以改善洛阳市轨道交通站点的步行接驳状况。

考虑交通韧性的基于MGWR模型的建成环境对公交客流影响分析

以北京市公交客流数据为分析样本,结合兴趣点及用地等多源数据,选取北京市6个城区作为研究对象,运用多尺度地理加权回归模型(MGWR)探究公交站点周边建成环境对公交客流的影响,并与其他模型进行对比分析。结果表明(1)相较于全局模型(OLS),考虑空间异质性的局部模型(MGWR和GWR)在探究公交客流与建成环境的关系上表现出更优的评价结果,MGWR的拟合效果最佳;(2)公交客流受多因素影响,并在空间上呈现出明显的聚集性;(3)各变量的影响程度体现出空间异质性规律,商业服务设施和交通服务设施与公交客流存在正相关,增强相关设施的建设,不仅有助于公共交通的发展,还能提升城市交通系统在面对突发事件或变化时的适应性和恢复能力,从而提高城市交通韧性。

公平视角下的TOD模式研究进展与展望

在传统TOD模式中,尽管城市发展得到了促进,但地价上涨等导致的社会不公平问题逐渐显现。ETOD(equitable transit-oriented development)则通过强调公平性,为弱势群体提供更多的保障性住房和便捷的交通服务,文章探讨了公平导向下的交通发展模式,分析了其在国内外的研究进展和应用前景。通过系统的文献综述,结合国内外相关文献,识别了ETOD领域的研究趋势和空白。重点分析了ETOD模式下的住房公平性和交通公平性问题,并强调了拓展ETOD研究范围以涵盖环境可持续性和无障碍设计原则的必要性,充分揭示了ETOD在解决社会不公平问题方面的潜力。

National Standards for Urban Rail Transit

In this paper, we suggest the creation of passenger service standards for urban rail transit. We put forward standards suited for China's actual conditions, aimed at meeting an international level of service based on customer-oriented principles.

Risk of COVID-19 Spread and Mitigation Strategies in Public Transportation Sector

The world is trying to recover from once in the COVID-19 pandemic, which has a higher mortality rate than the common flu. However, the threat of different variants is still affecting us in a different capacity. Several preventive measures have been adopted across the nation and the globe to avoid the spread of this virus, such as lockdown, restricted travel, social distancing guidelines, obligatory face mask use, etc. These activities directly influenced the management of social life, economy, and livelihoods. The effect of COVID-19 on the public transit industry and strategies the transit agencies adapted to continue providing the service during the pandemic has been synthesized in this paper. As a result of the pandemic, public transit ridership decreased by about 70 percent for most agencies compared to pre-pandemic levels. This article also highlights the prevention of COVID-19 spread in the public transit industry using engineering solutions and advanced material science and nanotechnology solutions.

集中回风模式下单跨拱形地下车站公共区气流组织模拟分析

[目的]单跨拱形地下车站因层高较高,并采用拱形顶板的特殊结构形式,对装修提出了较高要求。因此,在合理的气流组织前提下,有必要研究如何减少单跨拱形地下车站公共区的通风空调管线,为装修提供更大创新空间。[方法]以深圳某单跨拱形地下车站为例,提出了公共区采用集中回风模式,以及送风管兼排烟功能的设计思路;通过CFD(计算流体动力学)软件模拟分析在相同制冷量和相同送风温差的条件下,单送单回和集中回风两类送回风模式在单跨拱形地下车站公共区内的气流温度和速度分布规律,研究调整集中回风口位置对公共区气流组织的影响,并利用不均匀系数作为效果评价。[结果及结论]地下车站公共区采用集中回风模式,以及送风管兼排烟功能的设计可有效减少公共区的站厅风管数量约50%,截面积约40%,有效减少站台风管截面积约50%;采用公共区集中回风模式,集中回风口单独设置在站台,以及送风管兼排烟功能的布置方式,气流温度和速度分布均达到较优水平,能满足乘客的舒适度要求,可适用于单跨拱形地下车站公共区的气流组织。

共享单车与公共交通多元关系分类及阈值研究

为准确评估共享单车和公共交通之间的复杂时空关系,根据替代或补充关系的具体成因类型,结合共享单车出行起讫点的分布情况,定义共享单车与公共交通多元关系;其次,考虑公共汽电车与轨道交通的差异性,提出一种基于弱监督全连接神经网络的共享单车与公共交通多元关系的分类模型,并根据共享单车轨迹数据,计算不同关系分类和交通方式下的公共交通可达范围、共享单车骑行时长及步行接驳距离边界阈值。结果表明:共享单车与公共交通的多元关系可分为接驳补充、空白补充、替代关系1和替代关系2。其中,共享单车与公共汽电车多元关系的三参数划分阈值分别为329.75 m、5.07 min和182.93 m,与轨道交通多元关系的划分阈值分别为816.96 m、10.27 min和653.91 m。共享单车与公共汽电车以替代关系1为主,占总行程的54.98%;共享单车与轨道交通以空白补充关系为主,占总行程的48.90%。共享单车与公共汽电车关系主要为多元替代与接驳补充,与轨道交通主要为多元补充与替代关系2。共享单车与公共汽电车的关系相比于轨道交通会更为复杂。本文可为促进共享单车与公共交通在各自优势距离上的协同发展提供支撑。