Urban Railway Research Articles

A passenger service revolution? Transport design and passenger experience on Tokyo’s urban railway network, c. 1945–2010

This article discusses the history of efforts to shape passenger experience aboard urban railways through transport design. Taking Japan National Railways (JNR) trains as a case study, it examines the development of design interventions and organisational polices seeking to increase passenger comfort on Tokyo’s urban railway network in the second half of the 20th century. Industry and popular accounts have often tied the improvement of transport quality and passenger experience aboard JNR trains to its privatisation in 1987. In contrast, this article shows that passenger-oriented transport design has been an integral component in a continuous project to make urban railway travel more pleasant that long preceded this 1987 change in governance structures but has been held back by organisational and structural challenges. In doing so, it highlights that transport design involves the conscious shaping of both the “hardware” (i.e. physical transport infrastructure) and “software” (i.e. passenger-staff interactions) of service, as well as the backstage modification of organisational structures and processes that facilitate this framework. Built on a qualitative analysis of Japanese industry publications, newspapers, and secondary sources, the article thus contributes to literature on passenger experience, mobilities design, and transport history.

Disentangling the invasion process of subtropical native forests of Uruguay by the exotic tree Ligustrum lucidum: establishment and dominance determinants

BackgroundWhat factors, processes and mechanisms regulate invasive processes and their effects? This is one of the main questions addressed by the ecology of biological invasions. Ligustrum lucidum, a tree species native to East Asia, became an aggressive invader of subtropical and temperate forests around the world. We analyzed here the L. lucidum invasion in Uruguayan forests to determine the factors controlling two stages of the invasive process, the establishment, and the dominance. Establishment was assessed by the occurrence, measured in 1525, 1 × 1 km-cells, and dominance by remotely measuring the L. lucidum coverage at the forest canopy in 5554, 1 × 1 km-cells. The occurrence and dominance were modeled using Generalized Linear Models in function of independent environmental and geographic variables.ResultsLigustrum lucidum has become established in 13.4% of the Uruguayan forests and has dominated the forest canopy in 1.2%. Our models explained 45% and 35% of the occurrence and dominance spatial variance respectively and detected in both cases strong diffusion patterns from the S-SW region to rest of Uruguay. Occurrence increased mainly in function of urban areas, and with the proximity to towns, probably because L. lucidum trees planted in gardens are seed sources, and near railways and highways, that could function as biological corridors. Occurrence also increased in loamy soils and near rivers, suggesting moisture conditions are favorable for establishment. Dominance increased with reduced forest area, in high productive soils and at higher altitudes. Moreover, dominance increased near urban areas, roads, and railways, as well as in highly afforested landscapes, and in loamy and low-rockiness soils.ConclusionsThe invasion of Uruguayan forests by L. lucidum is in the spread and impact stages, currently in expansion from the invasion focus on the S-SW region, where the oldest urbanizations are settled, towards the rest of the country. The geographic proximity to the invasion focus is currently the main predictor of both L. lucidum establishment and dominance. Additionally, whereas establishment is manly facilitated by human infrastructures improving propagule pressure and dispersion, dominance is enhanced in small or fragmented forest patches, in rich-nutrient soils, and at higher altitudes, suggesting ecosystem resistance is also operating.

Characteristics and Mechanism of Sound Radiation of Urban Railway Bridge Installed with Sound Barrier

In noise-sensitive areas of urban rail transit (URT), sound barriers are often used to block the propagation of on-track noise such as the wheel–rail noise. However, the vibrations induced by passing trains can also transmit to the sound barriers. Therefore, it is necessary to study the acoustic radiation characteristics of the sound barrier under moving train loads and to evaluate whether installing sound barriers will affect the overall low-frequency noise radiation from the elevated railway. In this paper, the train–track–bridge dynamic interaction theory is adopted to establish a dynamics model for train–track–bridge-sound barrier coupled system, and the acoustic theory is employed to establish acoustic boundary element models for sound barrier, box girder bridge and sound barrier-box girder bridge coupled system, respectively. These models are then used to systematically analyze the characteristics and mechanism of vibrational noise of the sound barrier due to passing trains. The effects of sound barrier on the acoustic environment are also evaluated. Finally, the influencing mechanism of sound barrier on low-frequency acoustic radiation of elevated railway is investigated, and suggestions for future research on low-frequency acoustic radiation of elevated railway are presented. The research results show that the sound barrier can become a significant low-frequency sound source during the trains passing. Installing sound barriers on elevated railway affects the sound environment around the railway mainly through acoustic effects on the noise propagation. The installation of sound barriers has an effect on the vibration characteristics of the box girder bridge. In order to explore the characteristics of low-frequency sound radiation of elevated railways installed with sound barriers, it is necessary to reanalyze the acoustic generation mechanism of the entire structure of the bridge-sound barriers coupled system and combine it with the propagation mechanism of various sound sources.

Research on Safety Assessment Indicators of Gas Extinguishing System for Urban Railway Transportation

Gas fire extinguishing system as a more widely used system in urban rail transit, its safety is related to the safety of passengers, lives and property. At present, there are few studies on the safety of gas fire extinguishing system, and there is no special standard to guide. In order to improve the safety of the subway gas fire extinguishing system, through a number of operating companies and manufacturers to conduct on-site research, and the use of theory and data analysis and other methods of gas fire extinguishing system safety indicators have been studied. Reliability analysis is carried out by using Fault Tree Analysis, and on this basis, the safety evaluation of the system is further quantified by identifying and analyzing the hazards of the gas extinguishing system and rating the risk of the system by using semi-quantitative method. The results show that the average working time index of the gas extinguishing system before hazardous failure is 173 years, and the average non-hazardous failure time is 173 years.

Incident Delay Prediction in Urban Railway Systems: Methodology Review and Exploratory Comparative Analysis

Incident Delay Prediction in Urban Railway Systems: Methodology Review and Exploratory Comparative Analysis

Model for Intercity Railway Schedule Optimization Incorporating Metrorail Transfers

The promotion of multimodal coordination is of great significance for the joint development of diverse urban transportation systems. Focusing on a comprehensive urban passenger transport hub that converges both intercity modes and multiple inner-city modes, our study aims to incorporate intercity railway and Metrorail coordination into train scheduling optimization to enhance transfer efficiency and provide a seamless service for passengers in urban railway networks. By considering the variety of passenger demands in different transport modes (e.g., rail transit and traditional mainline railway), train loading capacity, and potential disruption scenarios, we specifically developed a mixed-integer nonlinear programming (MINLP) model to simultaneously generate the coordination strategies, arrival/departure times of trains at each station, and the number of carriages in service in the network. To enhance computational efficiency, we proposed several improvement strategies involving the model linearization to reformulate the MINLP model into a mixed-integer linear programming (MILP) model and the determination of appropriate big- M values. Finally, numerical experiments based on historical passenger data from a realistic urban railway network in China were implemented to verify the effectiveness of our approach. The results demonstrate that our intercity railway and Metrorail coordination strategies could, in practice, significantly improve passenger transfer efficiency by over 35% compared with the train schedule without coordination.

Effects of train speed and passenger capacity on ground vibration of underground suburban railways

This study aims to explore the optimal driving speed for ground vibration in suburban railway underground sections. We focused on the ground surface of suburban railway underground sections and developed a 3D finite element dynamic coupling model for the tunnel–soil system. Subsequently, considering factors such as train speed and passenger load, we analyzed the propagation characteristics of ground vibration responses in urban railway underground sections. The research results indicate a significant amplification phenomenon in the peak power spectrum of measurement points near the tunnels in underground sections. The high-frequency components of the power spectrum between measurement points are noticeably higher between the two tunnels. Furthermore, as the train speed increases, this amplification phenomenon becomes more pronounced, and the power spectrum of each measurement point mainly concentrates on several frequency bands, with the amplitude of the power spectrum near the prominent frequencies also increasing. However, when the train speed is between 100 and 120 km/h, the impact on the amplitude of the power spectrum at measurement points above the running tunnel is minimal. Additionally, the amplitude of the middle-to-high frequency components in the power spectrum increases with the increase in passenger numbers. The impact on the peak acceleration amplitude at each measurement point is minimal when the train speed is 80 km/h or below. However, once the train speed exceeds 80 km/h, the peak acceleration amplitude above the running tunnel rapidly increases, reaching its maximum value at 113 km/h, and then gradually decreasing.

Towards a history of transit etiquette: the development of orderly boarding practices in Tokyo

This article is a call for the historical study of transit etiquette: the behavioural expectations that guide the mundane conduct of transport users. It identifies the formation of contemporary protocols of transit etiquette as a productive line of scholarly inquiry by taking the transformation of (de)boarding behaviours in Tokyo between the 1880s and the 1960s as a case study. Zooming in on urban railways in the Japanese capital, it describes the processes through which (de)boarding practices grew more elaborate in character and more narrowly defined in terms of the spatio-temporal location at which they could be legitimately exercised. It examines three groups of factors that contributed to this process: “software” and “hardware” interventions in transport operations as well as their broader historic context. Simultaneously, it cautions against linear narratives of consistent improvement by stressing the contradictions of this process. The article contributes to mobility studies by calling attention to the malleability and socio-technical construction of the norms that guide mundane mobility practices. It provides a provisional template for subsequent historical accounts of transit etiquette, and argues that such studies can empower research on mobilities and transport to contribute to wider debates about (in)civility and the organisation of urban life.

Rigid inclusions performance as ground improvement for lacustrine clays

The Bogotá urban railway system involves constructing a rail maintenance yard covering 33 ha near the Bogotá River. It requires the construction of a 4.1 m embankment to overcome flood risks. Approximately 57,000 rigid inclusions (RI) were installed because of poor soil conditions to control excessive settlement. The embankment and RI were placed on a lacustrine deposit comprising layers with high organic matter content and soft clays that extended up to 200 m below ground surface. The effects of RI installation were reviewed using an inclinometer and benchmark data. Proof static load tests (SLT) and CPT were performed after RI installation to verify RI performance. CPTs were completed in the soil adjacent to the RI, as tested by the SLT. Different time spans were considered after RI installation for the CPT to assess the evolution of soil properties. The SLT uses the estimated working loads factored in by at least 20%. The CPT results showed that after a relatively short period of RI installation, the soil properties were similar to the initial properties. SLT results showed that RI capacity and head displacements were within the admissible ranges, considering that they had no competent bearing stratum, demonstrating the effectiveness of the ground improvement method. The results of both tests demonstrate the effectiveness of RI as a ground improvement technique for lacustrine soft clay in Bogotá.

Adaptive Vibration Monitoring of Railway Track Structures Using the UWFBG by the Identification of Train-Load Patterns

Due to the capability of multiplexing thousands of sensors on a single optical cable, ultra-weak fiber Bragg grating (UWFBG) vibration sensing technology has been utilized in monitoring the vibration response of large-scale infrastructures, particularly urban railway tracks, and the volume of the collected monitoring data can be huge with the great number of sensors. Even though the train-induced vibration responses of urban railway tracks constitute the most informative and crucial component, they comprised less than 7% of the total operational period. This is mainly attributed to the temporal sparsity of commuting trains. Consequently, the majority of the stored data consisted of low-informative environmental noise and interference excitation data, leading to an inefficient structural health monitoring (SHM) system. To address this issue, this paper introduced an adaptive monitoring strategy for railway track structures, which is capable of identifying train-load patterns by leveraging deep learning techniques. Inspired by image semantic segmentation, a U-net model with one-dimensional convolution layers (U-net-1D) was developed for the pointwise classification of vibration monitoring data. The proposed model was trained and validated using a dataset obtained from an actual urban railway track in China. Results indicated that the proposed method outperforms the traditional dual-threshold method, achieving an Intersection over Union (IoU) of 94.27% on the segmentation task of the test dataset.

Temporal Variation and Spatial Heterogeneity in Boarding/Alighting Patterns at Urban Railway Stations: Implications for Estimating Optimal Construction Scale—A Case Study in Seoul, South Korea

Urban railways have become a prominent mode of public transportation within cities owing to their connectivity with other modes of transport and environmental friendliness. Various policies, such as the expansion of metropolitan areas and the development of megacities, have further emphasized the pivotal role of urban railways. Consequently, more railway stations are expected to be constructed in developed cities. However, the temporal variation in boarding and alighting patterns at each railway station is often overlooked. Failing to account for this variation, specifically the differences in peak-hour concentration rates, in railway station design may cause increased conflicts among users owing to concentrated demands during specific time periods, exacerbating congestion and diminishing the appeal of the urban railway systems. Therefore, this study investigated the correlation between the temporal variation in boarding and alighting patterns and the attributes (location) of railway stations in Seoul, South Korea, and analyzed the spatial heterogeneity of this correlation. Initially, the factors influencing the peak-hour concentration rates in railway stations were identified using a linear regression model. Peak hours were defined as morning and afternoon peaks and boarding and alighting were differentiated to account for the directional aspects of temporal variations in boarding and alighting patterns. The correlation between boarding and alighting patterns and the attributes of railway station influence zones was determined, and a geographically weighted regression model was estimated to analyze the spatial heterogeneity of this correlation based on railway station location. The analysis results revealed that railway stations in the southeastern and downtown areas of Seoul exhibited varying impacts of station attributes on boarding and alighting patterns even when the station attribute influence zones were identical. The contribution of this study is to evaluate the priorities of railway projects and its corresponding transportation policies. Regarding the policy goal recently announced by the Korean government, “Achieving Commute Times in 30-min range,” our finding will provide a good measure of accessibility whether it succeeds or not.

Protective effects of measures for railway subgrade adjacent to excavation of a parallel pit

The Hongqiao Airport–Pudong Airport urban railway construction project in Shanghai, includes a 156.1-m-long deep strip foundation pit that runs closely parallel to the subgrade of the Shanghai–Hangzhou High-speed Railway, operating at 300 km/h. With a maximum excavation depth of 25.5 m and a minimum distance of only 10.6 m between the outer edge of the pit and the subgrade slope foot, controlling the deformation of the foundation pit in soft soil and ensuring the safe operation of the adjacent high-speed railway present significant challenges. Various protective measures were implemented to mitigate subgrade deformation caused by pit excavation, including partition excavations, 1.5-m-thick diaphragm walls, a servo steel strut system, isolation piles between the subgrade and diaphragm walls, and water-resistant barriers. The foundation pit, soil, and railway subgrade deformations during excavation were measured and analysed. The results demonstrate that the protective measures limited lateral diaphragm wall deformation to within 0.14% of the excavation depth. The maximum horizontal and vertical displacements of the subgrade caused by excavation were 3.2 mm and 1.5 mm, respectively. As a result, trains safely passed through this section at a limited speed of 120 km/h. The findings presented provide useful reference information for similar projects.

Energy efficiency in urban electric railways

Dunia sedang bergerak menuju produksi nol CO2 dan membatasi kenaikan suhu global hingga 1,5°C pada tahun 2050 dengan mengurangi penggunaan bahan bakar fosil sebagai sumber energi yang tidak berkelanjutan. Sebagai transisi dari pengurangan ini, energi listrik telah menjadi sumber energi utama di sektor industri, transportasi, konstruksi, dan sektor lainnya. Di sektor transportasi, kereta listrik perkotaan telah menjadi mode transportasi pilihan oleh masyarakat di seluruh dunia karena standar keselamatan yang tinggi dan pelayanan yang unggul dibandingkan dengan transportasi darat lainnya. Namun, kereta listrik memerlukan jumlah energi yang signifikan untuk beroperasi, sehingga diperlukan upaya untuk mengoptimalkan penggunaan listrik secara keseluruhan. Makalah ini menyajikan kajian literatur terkait efisiensi energi listrik dalam bidang kereta listrik perkotaan, dengan menggunakan metode pengendalian kereta dan pemanfaatan sistem pengereman regeneratif sebagai strategi pemulihan energi yang paling efisien.

Effects of Lubricating Conditions on Wear Performance of U77MnCrH Rail

With the rapid development of railway towards being high speed and having heavy load capacity, the wheel–rail wear and rolling contact fatigue in the curve section with a small radius of freight have become the key problems in urban railways, which need to be solved urgently. The aims of this study were to compare the wear resistance with three different lubricating conditions on wheel–rail wear based on the wheel–rail rolling contact simulation tests. The wear loss, microhardness, and microstructure of the contacted surface of the rail were detected systematically. The results showed that the wear rates of rail were reduced by 71% for grease lubrication and 55% for solid lubrication, compared to those without lubrication. At the same time, the thickness of plastic deformation layer of rail samples were about 167 μm for the dry state, 138 μm for the solid lubrication state, and 128 μm for the oil lubrication state, respectively. It indicates that the thickness of the plastic deformation layer was significantly reduced under both grease and/or solid lubricating conditions. In addition, the microstructure of the deformation layer with two kinds of lubricated states was coarser and denser than that without lubricants. The average grain size of the deformation layer was approximately 0.22 μm under dry conditions and 0.32 μm under lubricated conditions. It also indicated that the changes in lubricants did not have a significant effect on the average grain size of the deformation layer. The results of the present study could provide theoretical reference for the development and design of lubricants used as rail materials.

Performance-Based contracting of urban transport operation Services: Evidence from Porto’s Light-Rail

This paper develops a bonus/malus incentive model for contracting out the provision of urban railroad operation services, and testing parts of its performance using Monte Carlo methods. We also provide evidence on the performance measures of Metro do Porto’s (MdP) light-rail network operation, during the 2010–2016 term of a bonus/malus-based contract, incorporating some features of our model. Results document that the implementation of a performance-based contract with an embedded incentive bonus/malus mechanism may contribute to promoting ridership patronage, increasing the average ride, and ultimately promoting the overall economic operating efficiency of the system. The comparative operating performance analysis of MdP versus Metropolitano de Lisboa, a vertically integrated, governmentally-owned metro network, shows that MdP exhibits higher revenue, cost, and operating efficiency in the 2010–2016 period, and that the bonus/malus mechanism induces the private sub-concessionaire to respond more efficiently to changes in demand.

A Study on LSTM-Based Lithium Battery SoH Estimation in Urban Railway Vehicle Operating Environments

A Study on LSTM-Based Lithium Battery SoH Estimation in Urban Railway Vehicle Operating Environments

Investigating noise radiation pattern of railway bridges for urban rail transit

Noise from elevated railway bridges in urban areas has been causing severe environmental issues. To find the peak frequency of sound energy and thus develop targeted countermeasures for noise mitigation, policymakers need a better understanding of the noise characteristics of urban railway bridges during train passage. This study approaches this issue by combining transient dynamic analyses and acoustic finite element simulation. Our frequency characteristic analysis focused on two primary noise sources: wheel-rail noise and bridge-borne noise. We built a spatial noise model that predicts the radiated noise of urban railway bridges in both the active and planning stages. The results show that the wheel-rail noise peaked at 800 Hz, 1600 Hz, and 3150 Hz, while the bridge-borne noise peaked at 40 Hz, 50 Hz, 80 Hz, and 125 Hz. The validation results demonstrated that the developed noise spatial prediction model extended well to similar urban railway bridges.

도시철도 인파사고 위험 관리 분석

This study aims to apply the Swiss Cheese Model to reduce the likelihood of crowd accidents on urban railways and to design measures that minimize damage when accidents occur. It examines various aspects from the initial concept of urban railways through to their design and operation, including laws and regulations, operational methods of responsible organizations, public awareness, and structural capabilities. The investigation includes analyzing variable relationships via confirmatory factor analysis and evaluating how five key areas influence crowd accident risks using multiple regression analysis. Findings suggest that the architectural design of stations and trains, the operational policies of railway entities, governmental traffic management strategies, the promotion of safety consciousness among citizens, and the preparedness for emergency situations collectively play a crucial role in managing these risks. Factors like the planning of train and platform capacities, effective risk communication by organizations, enhancing public risk awareness, and encouraging acts of kindness significantly contribute to mitigating crowd accident risks.

Developing a new method for improving the human resource reliability using the hybrid approach of SPAR‐H and DSM in the urban railway

AbstractAs one of the most important reasons of irreparable losses at work, human error is still a significant problem in spite of the rapid technological advancement and reduced role of humans in the systems set up and control. Therefore, with the aim of reducing human error, this study presents a new method to improve human reliability using the hybrid approach of SPAR‐H and DSM. For this purpose, the number of 53 tasks was specified for the terminal conductor using Hierarchical Task Analysis (HTA). Then, the error related to each task was calculated utilizing the Standardized Plant Analysis‐Risk Human (SPAR‐H) method, and based on the expert team's opinion. Next, the terminal conductor's tasks were entered into the DSM along with the error numbers and dependencies between tasks, and the most optimal arrangement of tasks was obtained by coding in MATLAB software. Finally, by using the SPAR‐H method, the error of the terminal conductor was calculated based on the new tasks arrangement and compared with the primary state. Based on the obtained results, the 30% increase in reliability shows the significant contribution of the optimal arrangement of tasks in reducing human error. The proposed method of this study helps managers to reviewing the task structure in high‐risk processes as an effective strategy to reduce human error.

Significant risks that trigger cost overruns and delays in urban rail projects: a typical case study of Vietnam

PurposeUrban rail projects are typically large-scale transport infrastructure projects (megaprojects) which have many potential risks that can influence the strategic goals of owners. However, there is a paucity of studies which explore the impact of risks on both “urban rail” project time and cost together considering quantitative assessments. Therefore, this paper focuses on investigating critical risks and quantifying such risk impacts on urban railway project schedule and cost in practice.Design/methodology/approachA combination of qualitative and quantitative research methods comprising semi-interviews with five experts and a questionnaire survey of 132 professional respondents is used. The data were modeled using Monte Carlo Simulation to predict the probability of project schedule and cost.FindingsThe results show that 30 risk variables are categorized into seven main groups which have significant impacts on both project time and cost. Outstanding five risk variables were highlighted as follows: (1) project site clearance and land compensation; (2) design changes; (3) physical project resources; (4) contractors’ competencies and (5) project finance. Such findings were supported by Monte Carlo simulation which predicted in the worst case that the project may suffer 11.03 months’ delays and have cost overrun with a contingency of US$287.68 million.Originality/valueThis study expands our knowledge about time and cost contingency of urban metro railway implementation across developing economies and particularly within the context of Vietnam. Policymakers will not only gain an understanding about risk structure but will also recognize the significant impacts of critical risk through risk impact modeling and simulation. Such an approach provides insights into risk treatment priorities for planners so that they can proactively establish suitable strategies for risk mitigation in practice.