Rail Rapid Transit Systems Research Articles

Dynamic Responses of Semi-Flexible Pavements Used for the Autonomous Rail Rapid Transit

The application of a semi-flexible pavement (SFP) is an effective solution to solve the rutting problems of the autonomous rail rapid transit (ART) system. The service environment of an ART pavement is significantly different from that of the conventional pavement due to the large axle load and high tire pressure of ART vehicles. A test section was constructed in the Zhuzhou ART system and a tire–pavement coupling FE model was built to explore the distribution features of the dynamic responses as well as to optimize the material and structural design. The tire–pavement coupling model was firstly verified by the field test data and then, utilizing the validated model, the parameter study was performed to analyze the influence of the vehicle operating state and pavement conditions. The simulation results show that the transverse tensile strain at the bottom of the SFP layer is dominant for the fatigue cracking of the pavement. Properly reducing the tire pressure can effectively improve the tensile environment at the bottom of the SFP layer. The action of the braking force may cause significant longitudinal tensile strains at the surface of the SFP layer and lead to transverse cracking of the semi-flexible ART pavement. The interlayer bonding between the SFP layer and the asphalt layer has significant influence on the amplitude and distribution of tensile stress at the bottom of the SFP layer. Moreover, to optimize the tensile environment of the semi-flexible ART pavement, the thickness of the SFP layer and the asphalt concrete layer cannot differ too much under the premise of meeting the requirements of rutting resistance performance.

Brake Instability Dynamic Model and Active Control Strategy for a Multiunit Articulated Rubber-Wheel Autonomous Rail Rapid Transit System

Due to the particularity of the structure, the dynamic properties of multiunit articulated rubber-wheel autonomous rail rapid transit system are very complex, which increases the difficulty of studying its braking stability. In this paper, a dynamic analysis model for the emergency braking of a multiunit articulated rubber-wheel autonomous rail rapid transit system is established by introducing the axle load transfer, suspension deformation compatibility equation, articulation force relationship equations, etc. Based on an in-depth analysis of the risks of the lateral swing instability and their formation mechanisms, an active control strategy for the multiunit articulated rubber-wheel autonomous rail rapid transit system under emergency braking conditions is innovatively proposed to ensure the stability of the vehicle, with the shortest braking distance as the optimization goal. Through simulation and experimentation, the established dynamic model is confirmed to approach the real vehicle well, and the feasibility of the active control strategy is proved.

Analyzing the Budgeting Process of Selected Rapid Rail Transit Systems

The transportation infrastructure in the United States is entering a period of growth and expansion. During this period of change, attention has been directed toward improving the organizational accountability of the rapid rail transit systems. To date, there has been no definitive study of how rapid rail transit systems integrate the operating budgetary process into decisionmaking or whether doing so would provide greater control over costs. Based on field interviews, this study examines the budgetary processes of 9 of the 13 rapid rail transit systems operating in the United States. Among the areas examined are (1) administrative issues, (2) budgetary planning, (3) frame of reference, (4) investigating variations from plans, and (5) planning feedback. In addition to describing the similarities and differences among the rapid rail transit systems, recommendations and observations are presented.

Light Rail and Land Use Change: Rail Transit’s Role in Reshaping and Revitalizing Cities

Planners and policymakers often cite the tangible objective of land use change as a primary motivation and justification for an investment in light rail transit (LRT). But how has light rail performed with respect to achieving this goal? This paper reviews and synthesizes the previous literature on LRT and other rail rapid transit systems in North America, demonstrating that rail transit alone is not a primary driver of land use change and that six beneficial factors affect the ability of these systems to have a measurable impact on reshaping and revitalizing cities.

Planning for Pedestrian Flows in Rail Rapid Transit Stations: Lessons from the State of Current Knowledge and Practice

Decades of research have contributed to the development of standards and models to guide pedestrian-friendly transit station designs, although it is not at all clear from the literature how these tools are collectively used in practice. To address this, we interviewed 15 experts in transit station design. Based on the themes identified in these interviews, we conducted an online census of all 16 transit agencies in North America with rapid rail transit systems with below-grade stations. We found that although standards and codes are most likely to guide design decisions, the three types of tools (published standards, deterministic models, and microsimulation models) are as likely to complement as substitute for one another. We recommend that such analytical models of passenger flow should consider explicitly how practitioners employ them in practice to better link future refinements to the more “pedestrian” world of engineering and design practice.

Vehicle Bridge Interaction in High-Speed Rail Corridors

Abstract: In this paper, our aim is to establish that Dynamic impact factor (DIF) is not only dependent on the span and type of the bridge but also dependent upon speed of the train and distance between axles of the train as well. Our current code i.e. Indian Railway Standards specify that DIF or Coefficient of Dynamic Augment (CDA) is dependent on span length and type of bridge but it is applicable for design speed up to 160 kmph. For any speed greater than that CDA shall need to be computed as per the dynamic analysis as per available international codes. As mentioned earlier that there is imminent need of high-speed rail network in India due to increase in economic activity, increase in travel choices, improvement in mobility, reduction in congestion and to boost productivity. Our objective of this project is to study dynamic response of a various types of bridges under high speed trains currently being used in India for high speed rail projects like RRTS (Delhi to Meerut and other corridors) and High speed rail project from Mumbai to Ahmedabad to accurately assess the DIF in bridges under the effect of different governing factors (vehicle speed, vehicle load, bridge superstructure type, etc). This study could be beneficial in upcoming projects of high-speed rail as it is our future need. This study is based on the current semi-high-speed rail network i.e. Delhi Meerut Rapid Rail Transit System (RRTS) being constructed and other corridors are to be implemented. Design speed of this project is 180 kmph hence existing IRS codal provision for DIF cannot be used, therefore, dynamic analysis is needed to establish the DIF. Dynamic analysis has been carried out with two types of boggie length i.e. 21.34m and 22.34m. In this project, we have started with the understanding of dynamic analysis by mentioning various codal provisions and parameters influencing the DIF. Subsequently, procedures for computation of dynamic analysis for given superstructure, loading, train type, span, etc have been explained including the modelling part. Last part of this study covers the dynamic analysis of various types of superstructure for given data

Evaluation of climate change resilience for Boston’s rail rapid transit network

• Assessment of rail rapid transit resilience to climate change. • Consideration of physical, topological, contextual aspects of system performance. • Presentation of sea level rise (SLR) impacts on a rail rapid transit system . • Sea level rise will create new flood pathways, inundating critical links and yards. • Resilience assessments can inform decision makers and adaptation planning efforts. Sea level rise (SLR) poses increasing flood risks to coastal cities and infrastructure. We propose a general framework of engineering resilience for infrastructure systems in the context of climate change and illustrate its application for the assessment of SLR impacts on the rail rapid transit network in Boston. Within this framework, projected coastal flood events are treated as exogenous exposure events, which interact with both physical and topological endogenous network characteristics. We consider contextual aspects of resilience by assigning relative importance to links based on passenger flows. Resilience is computed assuming a linear recovery model, neglecting recovery strategies. Using a reference 1–100 year coastal flood event we show decreasing resilience of the rail transit network as projected SLR increases. The proposed framework can be readily extended to consider more sophisticated performance models, recovery strategies, other perturbation events, and additional contextual factors, such as equity considerations.

Exploring the Interoperability of Public Transport Systems for Sustainable Mobility in Developing Cities: Lessons from Johannesburg Metropolitan City, South Africa

There have been growing concerns with regards to the state public transportation systems, particularly in the cities of developing countries. Chief among these concerns has been the lack of well-coordinated, efficient, and reliable transportation systems. The city of Johannesburg, just like any other fast-growing municipality in developing and emerging economies, has not been spared with regards to incessant public transport challenges. Consequently, there have been collective efforts from both public and private stakeholders to invest immensely in both innovative rail and road transport systems in the past decade. This article sought to achieve twin objectives. First, the work identified the state of connectivity between the rapid rail transportation and rapid bus transit systems based on Geoweb 2.0 data. Second, the work visualized the level of connectivity between these two modes to develop and formulate policy frameworks in integrating public transit systems in cities of the developing world, learning from the metropolitan city of Johannesburg. A mixed-method approach consisting of spatial and quantitative aspects was used to examine the state of connectedness and the promotion of access and mobility between the two modes. The local Moran’s I index was used to compute node clusters within the public transport system. Results from the analysis demonstrated that both high-clusters and low-clusters exist in the public transportation network, which have a high degree of centrality. It was revealed that commuters navigate from these nodes/stops with relative ease due to the short walking radius. However, the work revealed that most rail networks and bus routes, as well as the stations and bus stops, are not connected and are not significant in the local Moran’s I index, thus, making it difficult for commuters to conveniently move from the Gautrain to the Rea Vaya bus. There are, therefore, gaps with regards to the sharing of infrastructure between the two public transport modes and systems.

Accessibility to transit, by transit, and property prices: Spatially varying relationships

Accessibility to transit facilities is perceived to affect property prices. However, accessibility by transit has rarely elicited adequate scholarly attention in property price analyses. Additionally, previous studies on how transit accessibility affects property prices mainly focused on rail and bus rapid transit systems, while conventional bus transit, which is very popular in many contexts, has seldom been investigated. Moreover, whether there is spatial heterogeneity in the price (or capitalization) effects of conventional bus accessibility remains to be explored. To fill these gaps, this study aims to investigate the role of accessibility to and by bus in determining housing prices in a bus-dependent city where urban transit service is offered mainly by a bus system rather than other transit systems. Using a database of 4966 condominium units in Xiamen, China, this study develops a battery of spatial econometric models to estimate global and local relationships between to-bus and by-bus accessibility and housing prices. The findings are as below: (1) to-bus accessibility (measured by the number of nearby bus stops) is positively associated with nearby housing prices; (2) by-bus accessibility (measured by travel time to city centers by bus and bus frequency) significantly affects nearby housing prices; (3) spatial heterogeneity exists in the price effects of bus accessibility; and (4) bus frequency exerts a larger price effect in the peripheral area than in the central. Finally, practical and policy implications are discussed.

THE USE OF LIGHT RAIL OR LIGHT RAPID TRANSIT SYSTEMS BY INDIVIDUALS WITH SEVERE VISUAL IMPAIRMENTS

This study investigated the relationship between use of light rapid or light rail transit (LRT) systems by persons with severe visual impairments and independence in orientation and mobility. It found that orientation and mobility training on LRT systems would resolve many of the difficulties that users of the systems encountered. Modification that would make the systems more easily accessible to visually impaired travelers are suggested.

December 2019 Land Transportation News [Transportation Systems

Presents news of new rail transportation and rapid transit systems around the world.

Designing a resilient skip-stop schedule in rapid rail transit using a simulation-based optimization methodology

In recent years, rapid rail transit systems have played a unique role in transportation systems due to the demand increase in accommodating passengers. This study proposes a simulation–optimization method to improve the resiliency of the train timetable in rapid transit rail lines under uncertainty associated with the passenger flow and train running times. The aim is to evaluate the resiliency of the train timetable through a discrete-event simulation (DES) model and to provide an optimized schedule with the maximum degree of resiliency against random disruptions caused by passenger flow fluctuations. The problem is first formulated as a mixed-integer nonlinear programming model. The validity of the DES model is justified using convergence test analysis of the response variable, i.e., average passenger wait time, during the simulation run. Due to the complexity of the problem, a variable neighborhood search (VNS) and a genetic algorithm (GA) are proposed to solve large instances of the problem. A self-adaptive tuning approach is proposed to adjust the GA parameters. The benefit of the simulation–optimization approach is verified through numerical experiments based on real cases adopted from Line No. 1 of the Tehran underground metro system. The results indicate that the simulation-based optimization method could improve the resiliency of train services by almost 16.7%, on average, as against the all-stop service operation. The average improvement of using VNS as against the GA is about 47%. Also, VNS method provides better-quality solutions by average optimality gap of about 14% in all test instances when compared to an exact solution method, i.e., branch-and-reduce algorithm.

Mapping minibuses in Maputo and Nairobi: engaging paratransit in transportation planning in African cities

ABSTRACTOften called paratransit because of their flexible stops, schedules and routes, minibuses make up the bulk of public transport in African cities. Despite their ubiquity and importance, these systems are poorly understood by transportation planners who tend to focus on large-scale urban infrastructure projects such as highways, commuter rail or bus rapid transit systems. The assumption within much of this planning is that these minibus systems are barriers to change and will become at most secondary “feeder” buses within large-scale projects, but structured plans detailing this vision are lacking. This paper argues that frequent failure to collect data and value important paratransit systems as a critical part of transportation in their own right is deeply problematic from the point of view of equity, access and inclusive and effective planning. We ask whether the growing number of bottom up mapping projects of minibus systems can disrupt this status quo. By comparing two mapping projects, Digital Matatus in Nairobi and the Mapa Dos Chapas in Maputo, we find that inclusive, collaborative mapping can help render these minibuses more visible in planning and provoke more grounded and inclusive “planning conversations” on multi-modal integration, passenger information and minibus upgrading, all key but relatively marginalised aspects of creating accessible, low emission, high quality and safe public transport in African cities.

Effectiveness of rapid rail transit system in Beijing.

The effectiveness of rapid rail transit system is analyzed using tools of complex network for the first time. We evaluated the effectiveness of the system in Beijing quantitatively from different perspectives, including descriptive statistics analysis, bridging property, centrality property, ability of connecting different part of the system and ability of disease spreading. The results showed that the public transport of Beijing does benefit from the rapid rail transit lines, and the benefit of different regions from RRTS is gradually decreased from the north to the south. The paper concluded with some policy suggestions regarding how to promote the system. This study offered significant insight that can help understand the public transportation better. The methodology can be easily applied to analyze other urban public systems, such as electricity grid, water system, to develop more livable cities.

Land use and urban travel in Kumasi, Ghana

Globally, transport literature indicates a strong effect of land use on urban travel as people living in low density suburban areas tend to travel more by car than people living in high density urban areas. This is because in dense areas, public transport is organised more efficiently and travellers tend to travel shorter distances. However, this assertion is frequently based on locations with efficient integration of transport within the land use planning framework. In Ghana and many African countries, it remains unknown whether the effect of land use on urban travel is strong as reported in developed countries and elsewhere. This research examines the effect of land use on urban travel in Ghana using Kumasi, the second largest city in Ghana, as a case study. Simple questionnaire survey with urban residents, semi-structured interviews with agencies and secondary data analysis were used for this research. Results indicate negative effect of land use on urban travel as there has been increased congestion in all the major road arterials in the city resulting in difficulty in commuting using motorised transport. Findings further show a weak effect of land use on urban travel, as areas experiencing change of land use have poor locational accessibility. The paper recommends innovative ways of meeting the growing travel demand of residents in the city such as the development of a light rail and bus rapid transit systems to help ease congestion and improve public transportation.

Effects of new bus and rail rapid transit systems – an international review

ABSTRACTCities worldwide are implementing modern transit systems to improve mobility in the increasingly congested metropolitan areas. Despite much research on the effects of such systems, a comparison of effects across transit modes and countries has not been studied comprehensively. This paper fills this gap in the literature by reviewing and comparing the effects obtained by 86 transit systems around the world, including Bus Rapid Transit (BRT), Light Rail Transit (LRT), metro and heavy rail transit systems. The analysis is twofold by analysing (i) the direct operational effects related to travel time, ridership and modal shifts, and (ii) the indirect strategic effects in terms of effects on property values and urban development. The review confirms the existing literature suggesting that BRT can attract many passengers if travel time reductions are significantly high. This leads to attractive areas surrounding the transit line with increasing property values. Such effects are traditionally associated with attractive rail-based public transport systems. However, a statistical comparison of 41 systems did not show significant deviations between effects on property values resulting from BRT, LRT and metro systems, respectively. Hence, this paper indicates that large strategic effects can be obtained by implementing BRT systems at a much lower cost.

Traveler satisfaction in rapid rail systems: The case of Istanbul metro

ABSTRACTMultifaceted characteristics of urban travel have an impact on the passengers' overall satisfaction with the transport system. In this study, we investigate the interrelationships among traveler satisfaction, travel and traveler characteristics, and service performance in a multimodal network that comprises of a trunk line and its feeder lines. We analyze the factors influencing the choices of access to rail transit stations and the satisfaction of transit travelers with the rapid rail transit systems. We quantitatively study these relationships and demonstrate the complexity of evaluating transit service performance. Since the interrelationships among variables affecting this system are mainly stochastic, we analyze the satisfaction with transit system problem using a Bayesian Belief Network (BBN), which helps capture the causality among variables with inherent uncertainty. Using the case of Istanbul, we employ the BBN as a decision support tool for policy-makers to analyze the rapid rail transit services and determine policies for improving the quality and the level of service to increase the satisfaction with transit system. In the case study, satisfaction with accessibility and access mode variables are found to be more effective variables than total travel time for travel time satisfaction, confirming the significant role of access in multimodal travels.

Transit and Real Estate Rents

Although the literature is mixed on the association between transit proximity and real estate values, it is scant in relation to transit proximity and real estate rents. With CoStar asking-rent data for real estate within 1-mi corridors of several light rail transit (LRT), bus rapid transit (BRT), streetcar transit (SCT), and commuter rail transit (CRT) systems, the association between transit corridor proximity and rents at 0.5 mi and between 0.5 and 1 mi of transit corridor centerlines is estimated. For the most part, SCT has the most robust outcomes. This result is notable because economic outcomes to SCT systems may be the least understood given their recent emergence. LRT systems also have significant, positive associations between rents and corridor location. In contrast, results for BRT are mixed, with no statistically significant association with office rent, a negative association with the retail first 0.5-mi distance band, but positive effects for rental apartments. Across all development types, proximity to CRT corridors either has insignificant associations or significant, negative ones. On the basis of transit type, implications are offered for land use planning along transit corridors.

Setting services in public transit lines in short time periods under time-varying demand

Abstract: This paper focuses on a mathematical programming based model for setting the schedule of a given number of services on a public transportation network. The structure of the model is that of a time-expanded or diachronic network, where origin to destination flows vary dynamically over a short time horizon (several hours) and are assumed to be known deterministically. The model basically aims to minimize the total travel time of passengers during the time horizon by properly setting the lag times between services on the lines and thereby accommodating conveniently the schedules of the services on different lines in order to enhance transfers. Two different types of diachronic networks are considered, in which three basic algorithmic alternatives have been tested: a heuristic method based on the classical projected gradient, Benders decomposition, and a combination of both. Among other applications, the model can potentially be applied in operational aspects for disruption recovery in Rail-Rapid Transit and Suburban Railway systems by using bus shuttles or auxiliary bus lines. The computational viability of the model, in terms of adequate response time, is shown using test networks of auxiliary bus lines. Its computational performance in readjusting schedules for larger suburban rail systems is also evaluated.

Direct Ridership Model of Rail Rapid Transit Systems in Canada

A direct ridership model for Canadian rail rapid transit systems is presented. The goal of the study was to produce a ridership model to evaluate the specific context of Canadian rapid transit: no comprehensive model existed. Data were collected for Canada's five largest cities, including 342 stations with an average weekday ridership of more than 3 million passengers. Using bootstrapped ordinary least squares regression with station boardings as the dependent variable and 44 socio economic, built environment, and system attributes as potential explanatory variables, which were chosen after a review of the direct ridership model literature, the study yielded one model with an adjusted R2 value of .8033. The results are similar to those of models constructed in the United States with respect to densities, land uses, and station amenities, and socioeconomic variables do not appear to be significant. The absence of socioeconomic variables in the final model indicates that planners and policy makers have significant scope to exert influence over transit use through land use planning, design, and service features.