Urban Transit System Research Articles

Integrated Optimization of Transit Networks with Schedule- and Frequency-Based Services Subject to the Bounded Stochastic User Equilibrium

In many European metropolitan areas, the urban transit system is a mixture of schedule- and frequency-based services. This study proposes an integrated transit frequency and schedule design problem (ITFSDP), where frequencies and schedules are simultaneously determined, and develops a biobjective model for the ITFSDP to minimize operation costs and total passenger-perceived generalized travel cost. Meanwhile, the passengers’ route choice behavior is described by the bounded stochastic user equilibrium (BSUE). The in-vehicle congestion effect is represented using a set of constraints that differ in terms of the sitting and standing costs as sitting and standing passengers perceive crowding differently. This set of constraints captures the realistic behavioral feature that having occupied a seat, users remain seated at subsequent stops in the same vehicle. The problem is formulated as a mixed integer nonlinear programming problem, which is subsequently linearized to a mixed integer linear programming problem and solved using a branch and bound algorithm. A column generation and reduction phase is embedded in the solution algorithm to obtain the bounded choice set according to the BSUE constraints. Experiments are conducted to illustrate the model’s properties and the performance of the solution method. In particular, we demonstrate a Braess-like paradoxical phenomenon in the context of transit scheduling and highlight that well-synchronized transit services can deteriorate the network performance in terms of the total passengers’ generalized travel cost when considering passenger congestion costs because of crowding.

Public transit travel choice in the post COVID-19 pandemic era: An application of the extended Theory of Planned behavior

It is widely reported that the COVID-19 pandemic has reduced ridership and brought severe challenges to urban public transit systems in many countries. The impact of the COVID-19 pandemic on individual people’s choice of public transit may continue for a while after the peak of the crisis. However, there is insufficient detailed knowledge of how individuals respond in the post-pandemic context and make choices on public transit travel. This paper contributes fresh evidence for this by looking at Beijing as a case. The theoretical framework of the Theory of Planned Behavior is used to model individuals’ public transit travel choice-making processes along with three additional constructs representing the impact of the pandemic and the nature of urban mobility behaviors, namely perceived knowledge of COVID-19, the psychological risks of COVID-19, and travel habits. Structural equation modeling is used in model estimation. We point out that there may be potential differences between the effects and meanings of model constructs in the post-pandemic context and in normal daily context. Interestingly, despite the higher psychological risk’s negative effects, higher perceived knowledge of COVID-19 has significantly positive effects on people’s decision-making processes. A strong pre-pandemic personal habit of traveling by public transit has significant and positive effects on post-pandemic intention and perceived behavioral control. Group comparisons show that “captive” transit users have higher psychological risk of COVID-19 than “choice” transit users, yet their transit use decisions are less influenced by it. Based on the modeling results, more behavioral experiments are needed to further inform efficient policy-making.

Key Aspects for IT-Services Integration in Urban Transit Service of Medium-Sized Cities: A Qualitative Exploratory Study in Colombia

In the last ten years, approximately, urban transit systems of Latin American capital cities have evolved significantly. Colombia, specifically, has concentrated this development in its capital cities, consolidated through digital transformation programs in the transportation sector. However, the same phenomenon does not occur in medium-sized cities for different reasons that are important to analyze. This paper presents an exploratory qualitative study involving eight medium-sized cities in the implementation phase of their strategic urban transit systems. Three main aspects that drive this study were identified: technologies and their cost, functional requirements to implement information technology services in transit systems, and economy and administration associated with this type of implementation. Based on this, a semi-structured interview data collection instrument was designed, with the participation of 15 officials distributed in the eight target cities, and one expert from an intelligent transportation system in a capital city. With the information collected, an exploratory analysis was made contrasting the responses given by each interviewee. The most relevant results show that the interviewees prioritize technologies based on open standards to provide information to users; that the northern medium-sized cities of the country do not have strategies that regularize and motivate the use of public transportation; instead, the southern medium-sized cities of the country consider the use of transportation to be necessary. Finally, it was concluded that the information technology services to be included in the provision of transit services should promote these cities’ cultural and economic growth.

Niche-Based Microbial Community Assemblage in Urban Transit Systems and the Influence of City Characteristics

Niche-Based Microbial Community Assemblage in Urban Transit Systems and the Influence of City Characteristics

Tram Vehicle Selection for Urban Transit Systems by Using Modified Waspas and Bmw Techniques Based on the Weighted Power-Heronian Functions

Tram Vehicle Selection for Urban Transit Systems by Using Modified Waspas and Bmw Techniques Based on the Weighted Power-Heronian Functions

Topology analysis of Lanzhou public transport network based on double-layer complex network theory

The network topology is the basis of studying the overall performance and dynamic evolution mechanism of network. In regards to the study on the topology of multi-layer complex networks, the current studies fail to consider the heterogeneity of edges and nodes in multi-layer complex networks, and such methods are insufficient when they are used to analyze the static characteristics of topology. Therefore, this paper based on the theoretical basis of the multi-layer complex network, establishes a two-layer public transit complex network model where urban rail transit and bus transit cooperate with each other, and by optimizing this two-layer public transit complex network model, further proposes an integrated public transit network model. According to the method of analyzing the static statistical characteristics of complex networks, and considering the heterogeneity of nodes and edges in multi-layer network, this​ paper gives the evaluation indicators of static statistical characteristics of multi-layer public transit complex networks. Taking the two-layer public transit complex network structure in Lanzhou as an example, this paper finds out the main factors affecting its network stability and efficiency by analyzing the physical structure characteristics of this two-layer public transit complex network in Lanzhou where urban rail transit and bus transit cooperate with each other, and then puts forward the network optimization suggestions from the point of view of optimizing key nodes by using the method of identifying key nodes with centrality. In this study, the coupling among heterogeneous public transit network layers and the static structure characteristics of multi-layer public transit complex network are studied from the perspective of network structure, to assist the traffic management department in finding out the problems of the road network for the management and improvement of the performance and efficiency of the network. This has a profound influence on the development planning of urban public transit system.

Dynamic Grid-Based Spatial Density Visualization and Rail Transit Station Prediction

The urban rail transit stations are an important part of an urban transit system. Scientific and reasonable location of rail transit station can greatly alleviate traffic pressure. The number of people in the surrounding area of a rail transit station is an important factor for site selection. However, it is difficult to obtain the spatial distribution of population, which brings great difficulties in terms of site selection. Due to the large-scale popularization of AP (Access Point) in China, the spatial distribution of AP is used instead of population distribution to assist site selection. Therefore, a density visualization method based on a dynamic grid is proposed, which can help decision-makers intuitively see the AP density of the uncovered grid of rail transit stations, and then cluster the AP density of the uncovered area to predict the location of new rail transit stations. The validity of the proposed method is demonstrated by using the AP dataset and rail transit data of Beijing in 2013. The results show that our method has high accuracy in predicting the location of rail transit stations. It can provide data support for urban traffic development and management.

Full Battery and Hybrid Bus based Rapid Transit System as a Cost Effective Urban Transit Mode alternative to Metros in Tier II Tier II I Indian Cities

Intra-city travel is a significant part of urban life and a fully functional intra-city transit system will help in reducing the number of private vehicles on the road, thus reducing pollution and traffic congestions. A robust urban transit system helps in the physical expansion of city limits, making education, job, and medical facilities accessible to people living in city fringe areas. This will help in depopulating the Central Business District areas and optimization of real estate cost. Heavy Rail Based Metro Transit system has improved living conditions in Metropolitan cities. The High Capital Investment required for setting up a metro system necessitates the requirement of alternate Transit systems for Medium and smaller cities. This paper delves into this important area of suggesting an alternate urban transit model for Tier II and Tier III Indian cities. In this paper, modifications were suggested in the Metro Neo specification issued by the Ministry of Housing and Urban Affairs [10], to make it more cost-effective (to construct and maintain), agile, and with scope to harness new technologies as they become commercially viable in the future. Elevated or dedicated Busways with Full Diesel Hybrid Buses comprising an Energy Storage system (Li-ion battery pack) and a diesel power pack are suggested as the rolling stock for the transit system. This suggested rolling stock will be not only cost effective but also environmentally friendly. In the future, the Diesel Power Packs in the buses can be replaced with Hydrogen Fuel Cells or additional batteries to enable full electric and non-fossil fuel operation. The need for further research in developing cost-optimized structures in the Construction of viaducts and bus stations is felt and details in these areas have been highlighted. The suggested system will have the flexibility of a Bus Rapid Transit system and shall have some advantages of a metro system. Even in big cities with a full-fledged Metro system, the suggested modified Metro Neo system can act as a feeder system from faraway places. The paper proposes essential features of a transit system that is robust in present and is future-ready.

Full Battery and Hybrid Bus based Rapid Transit System as a Cost Effective Urban Transit Mode alternative to Metros in Tier II Tier III Indian Cities

Intra-city travel is a significant part of urban life and a fully functional intra-city transit system will help in reducing the number of private vehicles on the road, thus reducing pollution and traffic congestions. A robust urban transit system helps in the physical expansion of city limits, making education, job, and medical facilities accessible to people living in city fringe areas. This will help in depopulating the Central Business District areas and optimization of real estate cost. Heavy Rail Based Metro Transit system has improved living conditions in Metropolitan cities. The High Capital Investment required for setting up a metro system necessitates the requirement of alternate Transit systems for Medium and smaller cities. This paper delves into this important area of suggesting an alternate urban transit model for Tier II and Tier III Indian cities. In this paper, modifications were suggested in the Metro Neo specification issued by the Ministry of Housing and Urban Affairs [10], to make it more cost-effective (to construct and maintain), agile, and with scope to harness new technologies as they become commercially viable in the future. Elevated or dedicated Busways with Full Diesel Hybrid Buses comprising an Energy Storage system (Li-ion battery pack) and a diesel power pack are suggested as the rolling stock for the transit system. This suggested rolling stock will be not only cost effective but also environmentally friendly. In the future, the Diesel Power Packs in the buses can be replaced with Hydrogen Fuel Cells or additional batteries to enable full electric and non-fossil fuel operation. The need for further research in developing cost-optimized structures in the Construction of viaducts and bus stations is felt and details in these areas have been highlighted. The suggested system will have the flexibility of a Bus Rapid Transit system and shall have some advantages of a metro system. Even in big cities with a full-fledged Metro system, the suggested modified Metro Neo system can act as a feeder system from faraway places. The paper proposes essential features of a transit system that is robust in present and is future-ready.

On the Emergence of Sociotechnical Regimes of Electric Urban Water Transit Systems

Urban activities, including urban mobility, play a crucial role in climate change mitigation. Urban mobility is currently at a crossroads. In a business as usual scenario, CO2 emissions from urban transportation will grow by one fourth by 2050. Nevertheless, during this period, it may drop by about one third. To make the drop happen, we need to introduce comprehensive policies and measures. Electrifying urban transit is one feasible solution. This study investigates whether and how urban water transit systems have been electrified—a means of transport which has not been well researched in this respect. A multilevel perspective and the comparative case study method were employed to answer the research questions. The comprehensive study focussed on 24 cities representing the current experience in planning and operating water transport, based mainly on secondary, primarily qualitative, data, such as industry reports, feasibility studies, urban policies, and scientific papers. The primary outcome is that urban electric passenger ferries left their market niches and triggered a radical innovation, diffusing into mainstream markets. However, urban diversity results in various paths to electrification, due to the system’s physical characteristics, local climate and transport policies, manufacturing capacity, green city branding, and the innovativeness of international ferry operators. Three dominant transition pathways were identified—a comprehensive carbon neutral policy, a transport sector policy, and a research and development policy. From a multilevel perspective, cities can be considered a bridge between niches and regimes that provide the actual conditions for implementing sociotechnical configurations.

Techno-economic analysis of green hydrogen ferries with a floating photovoltaic based marine fueling station

The current study assesses the development of zero-carbon marine fuel production, storage and fueling for short-distance ferries from both technical and economic aspects. The solar driven integrated system is therefore designed in a stand-alone and carbon-free manner. The integrated system mainly consists of three parts: electricity production, hydrogen production and fueling, and hydrogen-driven propulsion systems. The land shortage of the urban environment is achieved by using a floating photovoltaic system, which is integrated with a proton-exchange membrane electrolyzer and a hydrogen tank to produce and store the hydrogen. A proton-exchange membrane fuel cell is used with auxiliary buffer batteries to power the propulsion system of ferries. A case study is carried out for the Toronto Island ferries urban transit system in Ontario, Canada. The current fossil fuel-driven ferry propulsion system is replaced with the proposed propulsion system with hydrogen fueling and production station. The developed system is thermodynamically and economically investigated where both energy and exergy approaches are used to carry out the thermodynamic analysis, and the cost comparison methods are deployed with various criteria, including internal rate of return, pay-back period and net present value. Also, additional maritime fuel comparison analysis is carried out for 2021 and 2030 cases at various hydrogen production capacities. A transient analysis is carried out to investigate the integrated system more deeply for each hour in a year to observe the vulnerabilities, provide more insightful details and maintain the decision-making process for component capacities. According to the case study, the proposed system's overall energy and exergy efficiencies in the grid-connected mode are calculated as 15.35% and 16.19%, respectively. The net present value of the proposed system is found to be 5.06 million Canadian dollars. The investment is paid back in 7.25 years with an 11.75% internal rate of return. The cost of hydrogen production, storage and fueling for the proposed system is found to be 6.47 Canadian dollars per kilogram at a 26.7 ton/year production rate.

A landscape planning agenda for global health security: Learning from the history of HIV/AIDS and pandemic influenza

This paper considers the role of landscape planning and design in the context of a growing need for research and policy recommendations associated with Emerging Infectious Diseases (EIDs), of which COVID-19 is the most recent. Beginning with a definition of EIDs and their origins within the context of landscape planning, the paper then argues that planning and design scholars and practitioners should begin by seeing the importance of a “global urban ecosystem” (GUE) comprised of rapidly transforming metropolitan and regional “patches” connected through “corridors” of relatively unregulated global transportation and mobility networks. It then revisits the history of the two prior global pandemics of HIV/AIDS and pandemic influenza to establish the importance of a landscape planning perspective at the intersection of wildlife, livestock, and globally connected human communities. The essay concludes by arguing that this GUE concept can facilitate creative planning and design by adapting concepts established in other patch and corridor networks like urban transit systems to the ongoing risk of future pandemic EIDs.

Building Architecture of Intelligent Control System for Urban Rail Transit System

The increase in the volume of passenger transportation in megalopolises and large urban agglomerations is efficiently provided by the integration of urban public transit systems and city railways. Traffic management under those conditions requires creating intelligent centralised multi-level traffic control systems that implement the required indicators of quality, comfort, and traffic safety regarding passenger transportation. Besides, modern control systems contribute to traction power saving, are foundation and integral part of the systems of digitalisation of urban transit and the cities. Building systems solving the traffic planning and control tasks is implemented using algorithms based on the methods of artificial intelligence, principles of hierarchically structured centralised systems, opportunities provided by Big Data technology. Under those conditions it is necessary to consider growing requirements towards software as well as theoretical design and practical implementation of network organisation.This article discusses designing architecture and shaping requirements for developed applications and their integration with databases to create a centralised intelligent control system for the urban rail transit system (CICS URTS). The article proposes the original architecture of the network, routing of information flows and software of CICS URTS. The routing design is based on a fully connected network. This allows to significantly increase the network bandwidth and meet the requirements regarding information protection, since information flows are formed based on the same type of protocols, which prevents emergence of covert transmission channels. The implementation of the core using full connectivity allows, according to the tags of information flows, to pre-form the routes for exchange of information between servers and applications deployed in CICS URTS. The use of encrypted tags of information flows makes it much more difficult to carry out attacks and organise collection of information about the network structure.Platforms for development of intelligent control systems (ICS), which include CICS URTS, high computing power, data storage capacity and new frameworks are becoming more available for researchers and developers and allow rapid development of ICS. The article discusses the issues of interaction of applications with databases through a combination of several approaches used in the field of Big Data, substantiates combination of Internet of Things (IoT) methodology and microservice architecture. This combination will make it possible to single out business processes in the system and form streaming data processing requiring operational analysis by a human, which is shown by relevant examples.Thus, the objective of the article is to formalise the principles of organising data exchange between CICS URTS and automated control systems (ACS) of railway companies (in our case, using the example of JSC Russian Railways), URTS services providers, and city government bodies, implement the developed approaches into the architecture of CICS URTS and formalise principles of organisation of microservice architecture of CICS URTS software. The main research methods are graph theory, Big Data and IoT methods.

Time-varying accessibility to senior centers by public transit in Philadelphia

Public transit offers older adults an important alternative travel mode for accessing social activity destinations. Given the growing size and socioeconomic diversity of the older population, transportation planners should consider how current urban transit systems can better meet their needs. In this study, we examine the time-varying accessibility to senior centers by public transit in each census tract of Philadelphia, Pennsylvania. Senior centers are community service and activity hubs for older adults which are typically overseen by the local area agency on aging. They offer a variety of services and social activities for older adults, including free meals, volunteering opportunities, information, and technology training. Using General Transit Feed Specification (GTFS) data and socioeconomic data from the U.S. Census Bureau, we analyze how accessibility varies across census tracts with respect to the tract's share of older adults, particularly those in vulnerable subgroups. We found that accessibility to senior centers declines from the downtown area to the suburbs but varies considerably among the vulnerable subgroups studied. We also found that when accounting for the open hours of senior centers, accessibility to senior centers is generally lower around midday (2 PM) than during peak hours (8:30 AM) on Mondays. We used the vertical equity index to examine social disparities in accessibility among older adults. We found that while SEPTA underserves neighborhoods with higher shares of older adults, tracts with higher shares of some vulnerable subgroups are better served than those with lower shares. Specifically, neighborhoods with higher shares of households that have no cars are better served than those with higher shares of African American and Hispanic older adults. These results suggest that the Southeastern Pennsylvania Transportation Authority (SEPTA) and the Philadelphia Corporation for Aging (PCA) should work together to better accommodate the diverse travel needs of older adults.

Operations Design of Modular Vehicles on an Oversaturated Corridor with First-in, First-out Passenger Queueing

Although urban transit systems (UTS) often have fixed vehicle capacity and relatively constant departure headways, they may need to accommodate dramatically fluctuating passenger demands over space and time, resulting in either excessive passenger waiting or vehicle capacity and energy waste. Therefore, on the one hand, optimal operations of UTS rely on accurate modeling of passenger queuing dynamics, which is particularly complex on a multistop transit corridor. On the other hand, capacities of transit vehicles can be made variable and adaptive to time-variant passenger demand so as to minimize energy waste, especially with the emergence of modular vehicle technologies. This paper investigates operations of a multistop transit corridor in which vehicles may have different capacities across dispatches. We specify skewed time coordinates to simplify the problem structure while incorporating traffic congestion. Then, we propose a mixed integer linear programming model that determines the optimal dynamic headways and vehicle capacities over the study time horizon to minimize the overall system cost for the transit corridor. In particular, the proposed model considers a realistic multistop first-in, first-out (MSFIFO) rule that gives the same boarding priority to passengers arriving at a station in the same time interval yet with different destinations. A customized dynamic programming (DP) algorithm is proposed to solve this model efficiently. To circumvent the rapid increase of the state space of a typical DP algorithm, we analyze the theoretical properties of the investigated problem and identify upper and lower bounds to a feasible solution. The bounds largely reduce the state space during the DP iterations and greatly improve the efficiency of the proposed DP algorithm. The state dimensions are also reduced with the MSFIFO rule such that all queues with different destinations at the same origin can be tracked with a single boarding position state variable at each stage. A hypothetical example and a real-world case study show that the proposed DP algorithm greatly outperforms a state-of-the-art commercial solver (Gurobi) in both solution quality and time.

Towards Smart City Governance. Case Study: Improving the Interpretation of Quantitative Traffic Measurement Data through Citizen Participation.

Citizens play a core role in sustainable cities as users of the services delivered by cities and as active participants in initiatives aimed at making cities more sustainable. This paper considers the role of citizens as information providers and discusses the conditions under which citizens can participate in the development of sustainable cities. The objective of this study is to document the sustainability of an urban transit system and evaluate its compliance, with citizen participation as a major contributor. The methodology used is intensive field visits, interviews, and a mixed analysis of Sant Andreu de Palomar District in Barcelona city. The circulating vehicles are quantitatively monitored, qualitative problems are detected, and the typology of vehicles and other aspects identified and detailed in the study are indicated. All this information is contrasted with that of the technological sensors in the sectors. The results indicate that vehicles in the current pattern of urban density planned under incorrect sensor operation influence sustainable behavior through agglomerative clustering. This paper provides recommendations for future urban sustainability assessment research, including the employment of mixed-methods research, among other strategies. This article is intended to assist policymakers and traffic engineers in evaluating the sustainability of urban transportation infrastructure projects considering citizens as sensors.

Bus OD matrix reconstruction based on clustering Wi-Fi probe data

The estimation of citywide passenger demand plays a vital role in system planning, operation, and management of the urban transit system. The Wi-Fi probe data, one of the emerging crowdsourcing data, is utilized to collect traces of smartphone users in this study. We establish a framework for OD matrix reconstruction, including extracting features for transit patronage and distinguishing them from non-transit users based on K-means clustering. Such a framework makes partial OD matrix more reliable. A probabilistic estimation method of bus OD matrix reconstruction is then proposed based on the partial OD matrix and the number of boarding and alighting passengers. A field study was carried out on bus line 5 in Suzhou, China. Compared to the measured ground truth, the difference in OD-level is 0.5–1.5 passengers per stop, showing that the proposed method for OD matrix reconstruction is reliable.

A bimodal transit system for large cities: cost efficiency and environment friendliness

This paper proposes a bimodal urban transit system with point-to-point transit (PPT) services considering the emission. PPT is designated to serve passengers with long travel distances, connecting two transport hubs with few intermediate stops. We focus on the bimodal system of FRT and PPT, formulating the joint design problem as a mixed-integer program through a parsimonious continuum model. The relative location between FRT and PPT stations varies over space, which complicates route choice analysis. We overcome the challenge by approximating the costs to access transit stations at an aggregate origin-destination level. This is validated by Monte Carlo simulation. Our findings show that the proposed system is both more cost-efficient and eco-friendly than the regular system in cities with high travel demand. However, its performance deteriorates as demand drops. Such a demand threshold is systematically examined in cities with different features such as geographical sizes, PPT speed, and income levels.

Investigation On High Temperature Superconducting Linear Flux-Switching Motors With Different Mover and Stator Pole Pitch Ratios For Urban Railway Transit System

Linear Induction Motors (LIMs) are popular as driving motors in urban railway transit systems due to their simple and robust stator structures. However, the efficiency and power factor of LIM are lowered because of its eddy effect. As a promising alternative, Linear Flux Switching Permanent Magnet (LFSPM) motor offers high electromagnetic performance while keeping its stator simple. Despite these merits, the adoption of Permanent Magnets (PMs) of LFSPM motors influences their flux-weakening ability, thus leading to narrow speed range. To solve this problem, it is feasible to use High Temperature Superconducting (HTS) coils to replace PMs, forming HTS Linear Flix Switching Motor (HTS-LFSM). Among various parameters that influence the performance of HTS-LFSM, ratio of primary and secondary pole pitches is a leading parameter. Aim at investigating the relationship between pole pitch ratios and electromagnetic performance, different typical pole pitch ratios are compared against each other based on several common principles. The merits and drawbacks are analyzed with the help of Finite Element Method (FEM), and some conclusions are drawn.

Scaling of contact networks for epidemic spreading in urban transit systems

Improved mobility not only contributes to more intensive human activities but also facilitates the spread of communicable disease, thus constituting a major threat to billions of urban commuters. In this study, we present a multi-city investigation of communicable diseases percolating among metro travelers. We use smart card data from three megacities in China to construct individual-level contact networks, based on which the spread of disease is modeled and studied. We observe that, though differing in urban forms, network layouts, and mobility patterns, the metro systems of the three cities share similar contact network structures. This motivates us to develop a universal generation model that captures the distributions of the number of contacts as well as the contact duration among individual travelers. This model explains how the structural properties of the metro contact network are associated with the risk level of communicable diseases. Our results highlight the vulnerability of urban mass transit systems during disease outbreaks and suggest important planning and operation strategies for mitigating the risk of communicable diseases.