Rail Transport Network Research Articles

Research on TOD Development and Location Selection among All Urbanized Areas – A case study in China

Currently, China is in the period of rapid urbanization and gradual improvement of the rail transportation network. With the increasing population in towns, the construction of many cities has become blind and disorderly to meet people’s housing needs, resulting in traffic congestion, uneven distribution of resources, and other “big city diseases” more serious. From the urban construction experience of developed countries, the mode that urban rail transportation and urban development complement each other and develop together, that is, the regional-wide TOD construction, is an effective way to promote sustainable urban development. This paper focuses on how to select the stations of the rail transit for priority development of TOD projects (TOD development advance sites) within the whole area of the town. When selecting stations, the investment potential and regional driving ability of each station are taken into consideration to make a comprehensive evaluation of each rail transit station, so that the TOD development advance sites can drive the gradual development of its surrounding areas and finally form an urban renewal pattern of interoperability and integrated development of the whole area. With this method, we can effectively solve the current situation of blind and disorderly construction of TOD and various problems in urban development in China, and help to build efficient, green, and livable cities in various places.

Determination of the influence degree of technologies for issuing train traffic safety warnings

This article focuses on assessing the quality of information based on the Bayes network to justify the effectiveness of internet technology in providing traffic safety in rail transport, while issuing speed reduction alerts. To achieve this goal, the following tasks were completed: technological schemes of data transmission and reception systems “P”, “Sh”, “E” “L”, “D” of rail transport network enterprise were presented; a Bayes network was formed, the probabilities of events were determined; conditional probabilities of control phenomena were determined. An existing and proposed system of issuing and cancelling warnings on Uzbekistan Railways has been studied. An evaluation based on the Bayes network has been carried out to justify efficiency in terms of data quality. One plot with a train serving intermediate stations was chosen conditionally. The transmission of alerts to these trains was carried out with two different systems. Technological operations are reduced to probabilistic relations. The model identifies a control event in four for comparison. The results showed the reliability of existing monitoring system data lower than suggested. This is due to the connection of the existing transmission system with each other, which allows the OBAUT system to control that all data is simultaneously transmitted and the transmitted data is received, regardless of the previous data. In addition, the level of subjective interventions for information transmission is also significantly reduced. OBAUT capabilities are considered much more efficient in terms of data quality, reliability and timely transmission. The widespread use of Information Technology in the network helps to improve the quality of data, and the addition allows you to make quick decisions in the organization of train traffic.

Recovery Strategies for Urban Rail Transit Network Based on Comprehensive Resilience

To enhance the resilience of urban rail transit networks in dealing with interference events and facilitating rapid network recovery, this paper focuses on studying damaged urban rail transit networks and proposes comprehensive resilience evaluation indexes for urban rail transit networks that take into account two dimensions: network topology and passenger travel path selection. A bi-level programming model is constructed to maximize the comprehensive toughness, where the upper-level model is an integer planning model for determining the optimal recovery sequence of the affected stations under interference events that result in station closure or inoperability. The lower-level model is a passenger flow allocation model aiming to minimize travelers’ impedance. A genetic algorithm and Dijkstra’s labeling algorithm are used to solve the upper model as well as the shortest path of the lower model, respectively. Using a real-world urban rail transit network as an example, this research applies different recovery strategies, random recovery, node importance-based recovery, and comprehensive toughness-based recovery, across five common interference scenarios to analyze the recovery sequence of stations in each scenario. The modeling results show that the comprehensive toughness-based restoration strategy yields the most favorable results for the rail transportation network, followed by the node importance-based restoration strategy. In addition, the network’s toughness varies more significantly when employing different restoration strategies during target interference, as compared to the random and range interference scenarios.

Optimization of fleet size and determining the optimal allocation of wagons in minerals transport network: A case study of Iran’s railway system

Rail wagon planning is an important type of planning in the rail transport network since its costs are high. Therefore, enhancing the accuracy of fleet planning could result in cost efficiency. In this research, we aim to model and optimize the fleet size and allocation problem in a rail transportation network. We proposed a novel two-step algorithm composed of two meta-heuristic steps to optimize the allocation of the fleet between origins and destinations and to determine the optimal number of wagons. Besides, we provided a case study of Iran’s minerals rail transport network. The results demonstrate that 4925 wagons are required to transport approximately 17.7 million tons of minerals per year, roughly 10% less than the current proportion. The validity of the results was also analyzed by using a comparison between our algorithm and CEPLEX for a test dataset. It is shown that our approach outperforms CEPLEX in terms of speed while retaining the same performance.

A comprehensive review of incremental launching method in the construction of prestressed reinforced concrete bridges in Vietnam

This paper discusses the implementation of the incremental launching method in the construction of prestressed reinforced concrete bridges in Vietnam. Since the 1990s, technology transfer has been initiated to develop and rapidly expand the country’s road and rail transport network system to support industrialization and modernization. Although the method was successfully applied in several bridge projects, the high construction cost has led to a controversial issue, and the government stopped its application in the country. The paper aims to analyze the limitations and unreasonableness in the project formulation, design survey, and procurement of technological equipment that led to the policy of stopping the application of the incremental launching method. The author provides an in-depth analysis to clarify the suitability of the policy and shed light on the issue’s root causes.

Evaluating Accessibility Based on the Combined High-Speed Rail and Air Transportation Network in China

Both high-speed rail (HSR) and air transportation networks have important impacts on accessibility to cities. However, few attempts have been made to analyze the combined modal accessibility of HSR and air, especially in the case of China. To fill this gap, this study aims to measure accessibility under a combined HSR and air transportation network in China. Average travel time (ATT), weighted average travel time (WATT), and potential accessibility (PA) are employed as indicators of accessibility. The results show that inter-urban accessibility under the combined network shows a decreasing trend from the central to the surrounding region, with the level of combined network urban accessibility significantly higher than that of either individual network. Under the ATT, WATT, and PA indicators, the combined network outperforms the HSR network by 46.53%, 47.69%, and 49.23%, respectively, and the airline network by 15.49%, 13.17%, and 75.45%, respectively. In addition, the combined network shows a more equitable distribution of accessibility than that of the HSR network.

Urban railway network expansion on transit oriented development: Improvement in accessibility in four Asian developing cities

Numerous cities in developing countries in Asia have focused on building rail transit networks using the transit-oriented development (TOD) policy to improve urban accessibility through public transportation. However, the hypothesis that expanding rail transport networks and implementing TOD policies will improve urban accessibility in developing cities has not been sufficiently analyzed. Therefore, this study selected four Asian cities of various sizes under different stages of development to explore how the expansion of rail transport networks and implementation in high-density development of the three TOD policies affect urban accessibility. The results suggest that rail transit network expansion would significantly increase overall accessibility, and TOD policy implementation would further increase accessibility in all cities. This study clarified that the desired urban structure of each city, which determines accessibility, significantly differs depending on the size of the city and existing and proposed networks.

Cross-border critical transportation infrastructure: a multi-level index for resilience assessment

Today, more than ever before, our society depends on interdependent infrastructure systems, such as transportation, energy, water, and telecommunications networks. These systems are often considered critical because they are necessary for the organization, functionality, and stability of a modern industrialized country. However, these infrastructures are vulnerable to accidents, malicious failures, and disruptions that could generate consequences impacting on the economy, health, safety, and welfare of the citizens of a country or of several neighboring countries. The disruption of critical cross-border transportation infrastructure, road or rail, as a result of a major event can affect the area where the event occurs and a wider area. Depending on the type and duration of an event, which can be natural or anthropogenic in origin, it is possible to estimate the impacts on the mobility of people and goods in terms of delays (alternative routes), increased traffic (congestion), and a potential increase in accidents. For instance, in 2019 there was an accident in Rastatt (Germany) that affected rail traffic on the Karlsruhe-Basel line of the Rhine-Alpine corridor in Europe. The rail line was disrupted for more than 50 days, causing disservices and about 2 billion Euro in economic losses in Germany, Switzerland, and Italy. The extended disruption of road and rail sections can have consequences (impacts) not only on the transport system but also on the socio-economic system in a macro-regional context. The research is part of the SICt project - Resilience of Critical Cross-Border Infrastructure developed in the Interreg VA Italy-Switzerland Programme 2014-2020. The work aims to define a RI - Resilience Index for the road and rail transport network falling within the study area. The RI index describes the capability of each network element (i-th link) to cope with a relevant event. The formulation of the index involves the calculation of three independent indicators: i) RIRM - Rescue Management related to the resources that can be activated and used to cope with an event; ii) RIPP - Plans & Management related to the speed with which the necessary resources can be activated and in fact, considers management aspects such as the presence of plans and procedures; iii) RIRN - Network & Traffic related to the robustness of the elements of the transport network. This work aims to present the proposed model and its application to the project area that includes the Lombardy Region (Italy) and the Canton Ticino (Switzerland) within the SICt Project.

Association between obese phenotypes and risk of carotid artery plaque among chinese male railway drivers

BackgroundChina has the world’s highest rail transportation network density, and the prevalence of obesity among railway workers in China is more than twice that of adults in the world. Carotid artery plaque (CAP) is a simple and noninvasive predictor of early atherosclerosis, while the association between different obese phenotypes and CAP risk among Chinese male railway drivers is unclear.MethodsThis cross-sectional study was performed among 8,645 Chinese male railway drivers. Obese phenotypes were assessed based on the obesity status (the body mass index ≥ 28 kg/m2 as obesity vs. < 28 kg/m2 as non-obesity) and metabolic status (metabolically healthy vs. metabolically unhealthy). Metabolically unhealthy was defined as the presence of at least one dysfunction, including elevated blood pressure, elevated fasting blood glucose, elevated triglyceride, and reduced high-density-lipoprotein cholesterol. Four obese phenotypes were defined based on the body mass index and metabolic status, i.e., metabolically healthy non-obesity (MHNO), metabolically healthy obesity (MHO), metabolically unhealthy obesity (MUO), and metabolically unhealthy non-obesity (MUNO). Multivariable logistic regression was employed to estimate the association between different obese phenotypes and the risk of CAP. Subgroup analysis was performed to examine the variation of the association by age, circadian rhythm disorders, and history of smoking and drinking.ResultsThe prevalence of CAP among male railway drivers in MHO, MUO, MUNO, and MHNO was 8.75%, 18.67%, 17.82%, and 5.36%, respectively. Compared to those with MHNO, an increased risk for CAP was observed among those with MHO (OR = 2.18, 95% CI: 0.82, 5.10), MUO (OR = 1.78, 95% CI:1.44, 2.21), and MUNO (OR = 2.20, 95% CI: 1.67, 2.89). The subgroup analysis showed that both of the metabolically unhealthy groups (MUNO and MUO) aged < 45 years were prone to a higher risk of CAP (for the MUNO group, OR = 4.27, 95% CI:2.71, 7.10; for the MUO group, OR = 4.00, 95%CI: 2.26, 7.17).ConclusionThe obese phenotypes are associated with CAP risk in male railway drivers, especially those with metabolically unhealthy conditions aged < 45 years.

Study on the Evolution and Resilience of Rail Transit Time Networks—Evidence from China

In the network operation and management of rail transit systems, the occurrence of unexpected events causes damage to the network structure, further hindering regional accessibility performance and the function of the system. This study is based on the rail transit operation schedules in 2009, 2013, 2016, 2019 and 2022. We construct a directional weighted rail transit time network (RNNT) with train operation time as the weight, compare the betweenness centrality, sum of the shortest time path and entropy importance, etc., and quantitatively measure the network accessibility, connectivity and its resilience evolution. The results show that the current rail transportation network in China has a “small-world” effect, and there are a few stations with strong connections. The most densely distributed intervals of travel times between pairs of nodes changes from [440, 445] to [207, 210]. The fastest and best-performing disturbance to network connectivity and accessibility performance are both caused by the betweenness disturbance strategy. When the network connectivity remains 80% effective, the ratio of failed nodes under the static betweenness centrality strategy decreases from 3.96% in 2009 to 2.31% in 2022, with weaker connections between node pairs, and their network resilience diminishes. When the network accessibility remains 80% effective, the ratio of failed nodes under the static (dynamic) betweenness centrality strategy increases from 0.13% (0.13%) in 2009 to 0.20% (0.23%) in 2022. Therefore, the rail transit network can protect the corresponding rail stations based on the station ranking of the above strategies, and this research is beneficial to rail transit network protection and structure optimization.

Estimating wider economic impacts of transport infrastructure Investment: Evidence from accessibility disparity in Hong Kong

Much recent work on transport and the economy has focused on ‘Wider Economic Impacts’ (WEIs) of infrastructure investment, the impacts other than time savings benefiting those actually using the transport network. Differential effects of transportation infrastructure by mode such as urban rail and road are relatively well known. However, impacts of other mode such as walking are scarce. This paper estimates wider economic impacts related to productivity from full rail, road and walking transport networks in Hong Kong in 2016. To the best of our knowledge, this is the first paper that makes use of complex network science indicators with spatial cognition-weighted accessibility combining full urban rail network, road network, and pedestrian network in capturing wider economic impacts. We use an instrumental variable approach to identify the causal effect of transport network centralities on productivity measured by gross value added. Our identification strategy largely relies on the exogenous variations from historical planned and existing transport networks. A first specification confirms the significance of urban rail and road. Specification with pedestrian network shows that pedestrian and rail networks can statistically significantly increase productivity in Hong Kong while roads play a less significant but still meaningful role. Our findings are robust to a variety of sensitivity tests such as using night-time light intensity and residential wage as alternative measures for productivity. The research suggests a key planning policy implication: place-based policies in a dense city require improvement in pedestrian and rail network structure that impacts local and global transport accessibility.

Simulation and Criticality Assessment of Urban Rail and Interdependent Infrastructure Networks

The role of urban infrastructure is becoming increasingly interdependent, resulting in new sources of vulnerability. Infrastructural asset failure can propagate between rail transportation and other infrastructure networks. There remains a lack of academic research focusing on the dynamic simulation of city-wide infrastructure using real-life data to quantify and cross-compare the criticality of assets. This paper aims to bridge this gap by developing a modeling methodology for interdependent urban infrastructure using complex network theory, which serves as a basis for investigating asset criticality and failure propagation. This modeling framework comprises the distribution of resource supply and demand, the topological representation and skeletonization of the infrastructure network, as well as modeling the propagation of asset failures. The framework is thereafter applied to a case study of the exposure of Greater London’s rail transportation network to failures from electricity infrastructure, selected as a representative example of interdependent infrastructures within a large-scale urban metropolitan area. Two time-based criticality metrics are also proposed to measure the topological extent of infrastructural failures and economic impacts resulting from the failure propagation of given initial failure scenarios. The results of the case study demonstrate that these proposed criticality metrics are effective in capturing the dynamics of failure propagation, and that topological metrics in criticality assessment do not always reflect the resulting economic damages of infrastructural failures.

Calculation of the Extra Capacity Required of Non-Fossil Fuel Power Generation Systems to Completely Phase Out Fossil Fuels

The task to phase out fossil fuels is now at hand. Most studies and publications to date focus on why fossil fuels should be phased out. This paper presents the physical requirements in terms of required non-fossil fuel industrial capacity, to completely phase out fossil fuels, and maintain the existing industrial ecosystem. The existing industrial ecosystem dependency on fossil fuels was mapped by fuel (oil, gas, and coal) and by industrial application. Data was collected globally for fossil fuel consumption, physical activity, and industrial actions for the year 2018. The number of vehicles in the global transport fleet was collected by class (passenger cars, buses, commercial vans, HCV Class 8 trucks, delivery trucks, etc.). The rail transport network, the international maritime shipping fleet, and the aviation transport fleet were mapped, in terms of activity and vehicle class. For each type of vehicle class, the distance travelled was estimated. Non-fossil fuel technology units that are commercially available on the market now were assembled to substitute fossil fuel supported technology. An example was selected to represent each vehicle class, for Electrical Vehicle and Hydrogen fuel cell systems. The requirements to substitute the ICE rail network and the maritime fleet with EV and hydrogen fuel cell systems were presented. The quantity of electrical power required to charge the batteries of a complete EV system was estimated. The quantity of electrical power to manufacture the required hydrogen for a complete H-cell system was estimated. An examination and comparison between EV and H-cell systems was conducted. Other fossil fuel industrial tasks like electrical power generation, building heating with gas and steel manufacture with coal were mapped and requirements for non-fossil fuel substitution were out estimated. The estimated sum total of extra annual capacity of non-fossil fuel power generation to phase out fossil fuels completely, and maintain the existing industrial ecosystem, at a global scale was 37670.6 TWh. If the same non-fossil fuel energy mix as that reported in 2018 is assumed, then this translates into an extra 221 594 new non-fossil fuel power plants will be needed to be constructed and commissioned. To mitigate intermittency of supply issues (from wind and solar) for just 4 weeks of production, global stationary power storage would require to be an estimated 574.3 TWh in capacity (or 74.6 million 100MW capacity stations).

Invited perspectives: Challenges and future directions in improving bridge flood resilience

Abstract. Bridges are critical-infrastructure components of road and rail transport networks. A large number of these critical assets cross or are adjacent to waterways and floodplains and are therefore exposed to flood actions such as scour, hydrodynamic loading, and inundation, all of which are exacerbated by debris accumulations. These stressors are widely recognized as responsible for the vast majority of bridge failures around the world, and they are expected to be exacerbated due to climate change. While efforts have been made to increase the robustness of bridges to the flood hazard, many scientific and technical gaps remain. These gaps were explored during an expert workshop that took place in April 2021 with the participation of academics, consultants, and decision makers operating mainly in the United Kingdom and specializing in the fields of bridge risk assessment and management and flood resilience. The objective of the workshop was to identify and prioritize the most urgent and significant impediments to bridge flood resilience. In particular, the following issues, established at different levels and scales of bridge flood resilience, were identified and analysed in depth: (i) characterization of the effects of floods on different bridge typologies, (ii) uncertainties in formulae for scour depth assessment, (iii) evaluation of consequences of damage, (iv) recovery process after flood damage, (v) decision-making under uncertainty for flood-critical bridges, and (vi) use of event forecasting and monitoring data for increasing the reliability of bridge flood risk estimations. These issues are discussed in this paper to inform other researchers and stakeholders worldwide, guide the directions of future research in the field, and influence policies for risk mitigation and rapid response to flood warnings, ultimately increasing bridge resilience.

A MULTI-SCALE BIM/GIS FRAMEWORK FOR RAILWAYS ASSET MANAGEMENT

Abstract. Climate change and urban transformations raise new challenges for decision-makers. The United Nations Sustainable Development Goals and The European Green Deal aim for a sustainable economy by reducing emissions of greenhouse gases. An essential task for reaching this result is to minimize transport emissions and their negative impacts on the environment and the human health. Rail is the future of sustainable transport system, and it can be part of the solution in achieving the decarbonisation target. In addition, even more people are using the train and the improvement of the service offered is an essential aspect to fulfil a greater demand for rail transport. More than five million people daily take the train in Italy, and this number is growing over time. It is demonstrated that more investment in rail infrastructure means a greater number of users, and this is even more true when considering the regional rail transport network. This ongoing research aims to test the potential of a Building Information Modelling (BIM) and Geographic Information Systems (GIS) integrated system employed to manage this type of existing infrastructure. A methodology was developed and partly tested on a case study. The purpose is the construction of a system that can be used across different phases of the process: linking the data resulting from BIM and GIS makes possible the development of a federated virtual model used as a single source of truth for project development and asset management.

Critical Analysis of Train Derailments in Canada through Process Safety Techniques and Insights into Enhanced Safety Management Systems

Canada’s rail transportation network is a critical part of Canada’s integrated supply chain which connects industries, consumers, and resource sectors to ports on the Atlantic and Pacific coasts. One transportation activity that is essential to most industries, especially oil and manufacturing, is the rail transport of dangerous goods (DG). Although rail transportation of DG is beneficial to Canada’s economy, not paying attention to the safe transportation of these types of goods can have irreparable effects on the economy, human lives, and the environment. Recent rail accidents, such as Lake Wabamun in 2005 and Lac-Mégantic in 2013, have shown that there is still room to increase the safety of transportation of DG by rail through improving railways’ safety management systems (SMS). As a result, investigations to increase the safety of rail transportation of DG have been started. This work is part of these initiatives focusing on enhancing railways’ SMS, particularly DG main-track train derailments. The current study applied detailed root cause analysis (RCA), the bow tie analysis (BTA), and incident databases to identify the main causes and consequences of these types of accidents (2007–2017). Then, the relationship between these factors and gaps in SMS elements were identified and the frequency of each factor was investigated. The results showed that the main gaps are related to process and equipment integrity, incident investigation, and company standards, codes, and regulations. Furthermore, some useful recommendations are presented to improve the management of each SMS element and reduce these gaps.

Robustness Assessment of Urban Rail Transit Network Based on the Interdependency Analysis: Chongqing Rail Transit in Jiangbei and Yuzhong as an Example

As transportation demand develops, urban rail transit networks become increasingly crowded, making them more linked and harder to manage. Furthermore, system failures and climate change are expected to increase the number of disruptions. Consequently, evaluating system robustness is critical to ensure it's operating safely. Complex network theory is used to investigate the overall topological structure of the urban rail transportation network (URTN). Attack strategies for URTN are designed when the topological and robustness analysis parameters have been calculated. According to the research, malicious attacks have a more significant effect on system robustness than random attacks. The proposed methodology is applied to the Chongqing rail transit in the Jiangbei and Yuzhong districts.

Rail transport network reliability with train arrival delay: A reference indicator for a travel agency in tour planning

As a tour agency plans a tour schedule with rail transport, it is necessary to evaluate the capacity of the rail transport network to determine the number of passengers in the tour group that can be served. This study develops a stochastic rail transport network (SRTN) according to the train timetable and tour schedule, such that each available train’s loading capacity (that is, the number of cars) may be fully and partially reserved for other requests. Under the consideration of a tour group including q passengers, the network reliability accordingly means the probability that the q-passenger group can successfully depart from a source station for a sink station via the SRTN. In addition, the passengers might not punctually change trains at a transfer station owing to train arrival delay. Because the travel agency cannot control the situation of train arrival delay while planning a tour schedule, the uncertainty of train arrival delay results in an acceptable delay probability that the passengers traveling by non-direct trains can successfully change trains and this must be considered for the network reliability evaluation. An algorithm integrating the minimal paths and the modified Recursive Sum of Disjoint Product are integrated to solve the addressed problem. A real case of a rail transport network in Taiwan is adopted to demonstrate the applicability of the proposed approach. The travel agency can view the network reliability as a reference indicator to evaluate the number of passengers in the group that can be served.

A simulation model of a traction network taking into account the variable resistance of the contact line and a given power profile of the electric vehicle in MatLAB Simulink

The article describes an approach to the development of a simulation model of an electric transport traction network, taking into account the change in the resistance of the contact wire when the vehicle is moving. The advantage of the model is that it is executed using the building blocks of Simulink, visually reflects the topology of the traction network, and can be used for modeling both trolleybus and rail transport networks. As the initial data for the model, both standardized drive cycles and experimentally obtained modes of vehicle motion can be used.

Research on Hub-and-Spoke Transportation Network of China Railway Express

China Railway Express is developing rapidly, but the point-to-point direct organization mode has brought many problems to it. Therefore, this paper proposes to construct a hub-and-spoke network and adopt the “collecting and transportation” organization mode. In this paper, based on the single distribution p-hub median problem, a dual-objective planning model was constructed by considering the characteristics of CR Express in terms of cost and time. In addition, considering the port as a key node of international rail transport network, it plays a vital role for CR Express. Therefore, a hub-port allocation model was constructed to determine the hub-port allocation relationship. Furthermore, a Lagrangian relaxation heuristic algorithm was designed to solve the model built for CR Express transportation network. Finally, based on the constructed model, the actual operation data of CR Express were used in the designed example to verify the effectiveness and applicability of the models and methods.