High-speed Rail System Research Articles

Monitoring and Evaluation of High-Speed Railway Turnout Grinding Effect Based on Field Test and Simulation

Turnouts are the weak spot in high-speed rail systems, and it is simple for the phenomenon of the wheel–rail force and the carbody lateral acceleration over-limit to arise when the train passes through, which affects the service life of the rail and the running stability of the train. In this paper, the turnout with wheel–rail force over-limit and carbody lateral acceleration over-limit is selected for analysis, and the profiles of the wheel and rail are monitored. Then, the vehicle–turnout coupled multi-body dynamics model is simulated. Additionally, the portable vibration analyzer, the comprehensive inspection train, and the wheel–rail contact dynamic stress tester monitors the data and evaluates the impact of rail grinding on high-speed railway. The results of this study demonstrated that the turnout profiles are in good agreement with the standard wheel profiles following grinding, and the wheel–rail contact point and equivalent conicity both improved. When the train passes the ground turnout at high speed with and without the wheel polygonal wear, the wheel–rail force and the carbody acceleration were clearly improved. Using the wheel–rail contact dynamic stress tester, the comprehensive inspection train, and the portable vibration analyzer monitoring the changes in the carbody acceleration, the wheel–rail force and the carbody acceleration are definitely better after grinding. Similar to the pattern in the simulation, the train’s running steadiness increased by grinding.

Color-Coated Steel Sheet Roof Building Extraction from External Environment of High-Speed Rail Based on High-Resolution Remote Sensing Images

The identification of color-coated steel sheet (CCSS) roof buildings in the external environment is of great significance for the operational security of high-speed rail systems. While high-resolution remote sensing images offer an efficient approach to identify CCSS roof buildings, achieving accurate extraction is challenging due to the complex background in remote sensing images and the extensive scale range of CCSS roof buildings. This research introduces the deformation-aware feature enhancement and alignment network (DFEANet) to address these challenges. DFEANet adaptively adjusts the receptive field to effectively separate the foreground and background facilitated by the deformation-aware feature enhancement module (DFEM). Additionally, feature alignment and gated fusion module (FAGM) is proposed to refine boundaries and preserve structural details, which can ameliorate the misalignment between adjacent features and suppress redundant information during the fusion process. Experimental results on remote sensing images along the Beijing–Zhangjiakou high-speed railway demonstrate the effectiveness of DFEANet. Ablation studies further underscore the enhancement in extraction accuracy due to the proposed modules. Overall, the DFEANet was verified as capable of assisting in the external environment security of high-speed rails.

Quadratically Constrained Linear Programming-based energy-efficient driving for High-speed Trains with neutral zone and time window

Among the numerous challenges that are faced during the daily operation of high-speed rail, the management of the neutral zones in the catenary during unexpected disturbances remains underinvestigated. This study proposes a computerised method for managing the operations of a high-speed train with regenerative braking for passing neutral zones under disturbance to minimise energy consumption. For the first time, different mechanism-based Automatic Passing Neutral Zone systems, including the Magnetic Induction System and Automatic Train Protection, are analysed and modelled as location-based and time-based constraints, respectively. Motion constraints caused by disturbances are described by time windows. Forced coasting and air brake-allowed passing neutral zone rules are considered in these models. The original nonlinear model with location-based constraints is transcribed as a quadratically constrained linear model and then solved. The optimality consistency and its establishment condition between the original and transcribed models are analysed based on the Karush–Kuhn–Tucker conditions. A high-quality solution is obtained when the establishment condition holds. The model with time-based constraints is novelly transformed into an optimal switching point problem. A series of sub-problems are iteratively and efficiently solved. Comprehensive experiments are conducted based on practical data from a high-speed rail system in China. The proposed method is significantly beneficial when compared to Mixed-integer Linear Programming and Artificial Driving Algorithms. Moreover, the impacts of different mechanism-based automatic passing neutral zone systems, operation rules, and a combination of time window settings are extensively analysed.

A System Optimization Approach for Trains’ Operation Plan with a Time Flexible Pricing Strategy for High-Speed Rail Corridors

Optimizing the train plan for high-speed rail systems should consider both the passengers’ demands and enterprise’s benefits. The choice of the departure time period is the most important factor affecting the passenger demand distribution. In this paper, the optimization problem of a train operation plan based on time period preference is studied for a high-speed rail corridor. First, according to the travel process of the passengers, the extended service network for a high-speed rail system is established. The main factors that influence the passengers’ travel choices are analyzed, and the departure time period preference, stop time and flexible pricing strategy based on the time period preference are put forward. The generalized travel cost function, including the convenience, ticket fare and stop time costs, is constructed, and a two-level programming model is established based on the function. The upper-level planning model is formulated as a mixed 0–1 programming problem that aims at maximizing the revenue of the railway enterprise. It is mainly constrained by passenger travel demand and solved by improved genetic algorithms. The lower-level model is a user equilibrium (UE) model. The Frank–Wolfe algorithm is used to allocate multiple groups of OD (origin and destination) passenger flows to each train so that the generalized travel expenses of all the passengers with the same OD are minimized and equal. Finally, the train operation plan is solved based on the Lan-xi (Lanzhou–Xi’an) high-speed rail data, and the validity of both the model and algorithm is verified.

Classification and determinants of high-speed rail stations using multi-source data: A case study in Jiangsu Province, China

High-speed rail (HSR) stations play a vital role in the HSR system. HSR stations not only facilitate the accessibility of interregional transportation but also stimulate population movements across various cities in China. HSR stations in different cities can vary greatly, and an efficient HSR system requires an in-depth understanding of the interrelations between the related influential factors and spatiotemporal passenger flow patterns of different HSR stations. This study adopts a new scheme for clustering HSR stations based on passengers' arrival and departure time series using mobile phone data in Jiangsu, China. To this end, 71 HSR stations are clustered into 3 classes and the spatiotemporal characteristics of passenger flow at different stations are compared. Finally, a geographically weighted multinomial logit model (GWMNL) is built to explore the influence of the built environment, socioeconomic indicators, and HSR station attributes on the classification results of HSR stations related to the time-varying characteristics of passenger flow. The model results show that the number of entertainment POIs, population, population density, area, GDP and building area are significantly associated with the classification results of HSR stations. Additionally, for HSR stations under the same classification result, these variables also have different effects on them in the geographical dimension. According to these findings, quantitative analysis of the linkages between the passenger flow patterns at different HSR stations and the impacting factors would offer implications for planners and policymakers in HSR station planning and associated urban development.

The combined effects of high-speed rail and aviation on tourist arrivals in China

Most provincial tourism destinations have both high-speed rail (HSR) and aviation transportation systems; the combined effects of those two modes of transportation on tourist arrivals are likely to vary depending on location. This study examines panel data from 31 provinces in mainland China over a ten-year period (2010–2019) using the Geographically Weighted Poisson Regression (GWPR) model to quantify the combined effects of HSR and aviation on tourist arrivals and their spatiotemporal heterogeneity. The empirical results reveal that: first, HSR and aviation do have a comprehensive impact on tourist arrivals, but the development trends of the two are distinct, with the impact of HSR increasing while the impact of aviation is declining; second, the combined effects of HSR and aviation are clearly spatiotemporally heterogeneous, and their effects on both domestic and inbound tourists exhibit distinct states in various places at various times; third, the GWPR model is an effective tool for determining the combined effects of HSR and aviation on tourist arrivals as well as their regional heterogeneity. This paper not only broadens the research on the combined effects of HSR and aviation from a new perspective and effectively describes the temporal and spatial changes of the combined effect, but it also provides targeted development suggestions for different provincial regions.

Does transportation infrastructure accelerate factor outflow from shrinking cities? An evidence from China

Shrinking cities have received increasing attention in recent years given that the emergence of these cities has raised concerns about social equity, stability and sustainability. While extensive studies have attempted to measure the structural changes from a demographic perspective, it remains unclear to what extent the development of transportation infrastructure may have influenced the formation of shrinking cities, especially considering a multi-dimensional structural change. This study fills this research gap by conducting a comprehensive impact assessment of transportation infrastructure on the development of shrinking cities in China, considering demographic, economic, and social changes. Based on the New Economic Geography theory, a novel multi-dimensional shrinking index system was developed and the characteristics of spatial distributions of different types of shrinking cities were analyzed using the GIS analysis. In particular, the impacts of two primary surface transportation modes (roadway and high-speed rail) on shrinking cities' performance were examined using a two-stage least-square model and a Difference-in-Difference model. The results confirm that both the development of roadway and high-speed rail systems have exacerbated the loss of critical factors, such as permanent population, in most shrinking cities, although the degree of impact varies by the different modes and dimensions of shrinkage. Specifically, transportation infrastructure mainly intensifies the losses of economic and social factors in shrinking cities, while the impact on demographic loss is negligible. The research findings suggest that future infrastructure investment and the strategies for urban governance should be implemented more selectively based on the different types of shrinking cities to achieve more sustainable and resilient urban development.

The Impact of High-Speed Rail Systems on Tourist Attractiveness in Italy: Regression Models and Numerical Results

This paper evaluates the impact of high-speed rail systems on tourist attractiveness in Italy. The analysis is carried out with reference to provincial capitals, only some of which are served by high-speed railway lines. To achieve this objective, two multiple linear regression models were specified and calibrated, which relate arrivals and presences in accommodation facilities to several factors that could influence the tourist destination: cultural, historical, and monumental heritage, commercial activities, recreational activities, accessibility, etc. Both models showed that the availability of high-speed railway services is an important factor in the choice of tourist destination, being, moreover, the only accessibility variable found to be significant; furthermore, the elasticity of tourist demand to this factor was significant too.

Spatio-temporal distribution of Chinese cities’ air quality and the impact of high-speed rail

Chinese government has set a goal to reach carbon peak and achieve carbon neutrality, endeavoring to gradually realize net-zero carbon dioxide (CO2) emission. Moreover, the new transport technology has also been fast developed, represented by the quick expansion of the high-speed rail (HSR) system in China. However, there has been very little investigation on how the HSR can affect city-level emission and urban air quality. Especially, the potential spatial spillover effect and the mechanism of such potential impact have not been examined. Based on the urban air quality index (AQI) of 286 Chinese cities over the 2016–2019 period, this study first adopts the spatial auto-correlation analysis to quantify the spatio-temporal characteristics of Chinese cities' AQI. Then, a spatial difference-in-differences (SDID) model and the spatial Dubin model (SDM) are estimated to shed light on how Chinese cities' air quality can be affected by HSR. This study identifies apparent spatio-temporal distribution patterns in Chinese cities' air quality. We found that the opening of HSR in Chinese cities significantly improves the urban air quality by reducing AQI by an average of 4%. Moreover, the spatial auto-correlation coefficient is 0.0897 and statistically significant. HSR opening in the adjacent city can also improve one city's AQI by an average of 1.3% (i.e., the neighboring effect). We also highlighted and verified the mechanism of such a positive HSR impact on the urban air quality. First, as a cleaner transport mode, HSR helps divert traffic from other more polluting modes. HSR also helps promote the city's tertiary industry, leading to fewer emissions. The heterogeneous analyses further demonstrated that HSR is more effective to improve the urban air quality in eastern region (with the AQI reduction of 5.88%) and western regions (with AQI reduction of 7.25%).

Influence of high-speed rail on the decentralisation of events from big metropolitan areas to smaller intermediate cities

International literature on High-Speed Rail (HSR) systems has comprehensively analysed the different socioeconomic impacts derived from the deployment of these infrastructures. The increasing phenomena of business tourism and events organisation in recent years have been identified as potential sources of revenue for cities interested in holding these events. However, few academic studies have identified the factors influencing cities’ location for these business events, such as conferences, meetings and conventions. Our study attempts to fill this gap.The main objective of this manuscript is to evaluate the impact of transport accessibility, especially HSR services, in choosing a city in which to locate an international event in Spain from the perspective of the event planner, focusing on the decentralisation of these kind of events from big metropolitan areas to smaller cities. To achieve this objective, a discrete choice model based on random utility theory has been estimated. The period analysed is 2003–2018; the cities analysed were selected guaranteeing that the panel analysis was heterogeneous, and that it was representative of the main types of cities present in Spain. The results show that besides potential accessibility, HSR provides an additional contribution to the attractiveness of a city as a possible place to locate events, especially small and medium-sized cities. In particular, the model estimation results show that the probability a conference will be organized in a small/medium city with an HSR station is about 21% higher than that of a small/medium city without HSR (in the case of all other variables relating to tourist attraction and meeting facilities being equal), while HSR has contributed to a reduction in international events in big cities.

Travel on the road: does China's high-speed rail promote local tourism?

Following a Chinese saying: To be rich, roads first, high-speed rail (HSR) opening and station construction are indispensable for economic developing. Probing the nexus between HSR, as a vital part of modern transportation system, and local tourism development provides a scan for reviving tourism and gaining low-carbon transition after COVID-19 pandemic. Drawing on prefecture-level panel data, this study takes difference-in-difference and instrument variable methods to detect the overall and heterogeneous effects of HSR connection on cities’ tourism development. The results showed that HSR connection had an overall positive effect on cities’ domestic tourist arrivals. The heterogeneity of the effect from HSR to tourism development appears to be that central and western cities, non-resource-based cities, and small cities benefited more from the opening of HSR. From a dynamic perspective, HSR connection promoted local tourism development in the 0 and 1 year of HSR opening but failed to show a positive effect in the long term. Hence, the study proposed some adjustments for evaluating the efficiency of HSR with consideration for the tourism effect, redesigning the system of HSR with consideration for local heterogeneity, and optimizing the HSR environment. These measures can optimize China’s HSR management and the design of HSR systems.

The impact of China's high-speed rail investment on regional economy and air pollution emissions

The high-speed rail (HSR) network in China has experienced rapid development since the 2000s. In 2016, the State Council of the People's Republic of China issued a revised version of the “Mid- and Long-term Railway Network Plan”, detailing the expansion of the railway network and construction of an HSR system. In the future, the HSR construction efforts in China will further increase, which is considered to impact regional development and air pollutant emissions. Therefore, in this paper, we apply a transportation network-multiregional computable general equilibrium (CGE) model to estimate the dynamic effects of HSR projects on economic growth, regional disparities, and air pollutant emissions in China. The results indicate that HSR system improvement could generate a positive economic impact but could also increase emissions. The gross domestic product (GDP) growth per unit investment cost stimulated by HSR investment is found to be the largest in eastern China but the smallest in the northwest regions. Conversely, HSR investment in Northwest China contributes to a substantial reduction in regional disparities in terms of the GDP per capita. In regard to air pollution emissions, HSR construction in South-Central China results in the largest increase in CO2 and NOX emissions, while for CO, SO2, and fine particulate matter (PM2.5) emissions, the largest increase occurs due to HSR construction in Northwest China. At the regional level, the provinces with large changes in accessibility also experience large changes in their air pollutant emissions.

A discussion on design fires for high-speed railway train cars

High-speed rail systems are expanding everywhere for carrying thousands of passen-gers every day. Train cars in underground spaces travel under dense urban areas, tun-nels in mountainous places and bridges across rivers. Design fire in burning a train car should be studied carefully for fire hazard assessment in those long underground or en-closed spaces. There are full-scale burning testing results on the main combustibles in-cluding seat, curtain and passenger luggage in some train cars. The heat release rate of a high-speed train car model CRH1 will be studied using such data together with a two-layer fire zone model, the Consolidated Model of Fire and Smoke Transport (CFAST). Simulation will be performed on the full-sized train car with the heat release rate of the seat measured by experiment. Two fire scenarios with ignition points located in the front and rear areas of the train compartment are considered. The results of the fire simulations show that the heat release rate can reach 43 MW. The value is similar to the full-scale burning experiments on train cars in Sweden and South Korea. Active fire protection systems have to be seriously considered in those underground or enclosed areas.

Evaluating the substitutability of short-haul air transport by high-speed rail using a simulation-based approach

Air transportation is reported to have the highest CO2 emission per passenger kilometer compared to other modes of travel. Although prior studies have analyzed the impact of high-speed rail (HSR) on the aviation sector, this study is one of the first to develop a simulation model to evaluate the current HSR system, and determine the extent to which the existing rail network can handle additional passengers, if short-haul airline customers were to avail of HSR service. This study also proposes recommendations for future HSR schedules and rail capacities, as well. A Define, Measure, Analyze, Design, and Verify (DMADV) approach is developed for (a) conceptualizing the problem, (b) collecting data from different sources, (c) developing the simulation model, and (d) evaluating the results and deriving managerial recommendations. For the purpose of illustrating the proposed approach, we discuss a case study considering the passenger travel between two major European cities, Munich and Paris. It can be observed that the current railway operations between Munich and Paris could only handle 25% additional customers. If 50%, 75% and 100% of current air customers were to switch to HSR, then it is recommended to operate one (evening), two (one afternoon and one evening), and three (two afternoon and one evening) additional trains, respectively. Furthermore, this study shows that a complete customer transition from air to rail could save 56.8% in CO2 emission.

Study of material recrystallized regions on deformation and cracking behaviours in cast steel brake discs

Localized regions of recrystallized material have been observed on steel brake discs used in high-speed rail systems. Because the effects of recrystallized regions on steel brake disc cracking behaviour are not well known, further study is warranted. In the present study, the characteristics of localized regions of recrystallized material were characterized by transmission electron microscope, and the coupled effect of severe braking thermal cycles and frictional shear force was found to be the root cause of material recrystallization. In situ tensile testing was used to compare the deformation and cracking behaviours in samples taken from a in-service railway brake disc and a virgin brake disc. The results showed that the localized recrystallized material degrades the mechanical properties of the in-service brake disc due to strain localization. The localized recrystallization of the material also changed the sample fracture from a ductile mode in the virgin steel brake disc to a mixed mode. Electron back-scattered diffraction (EBSD) analysis showed that the nonuniform distribution of low angle grain boundaries (LAGBs) and high angle grain boundaries (HAGBs) in the localized recrystallized material reflected strain localization. HAGBs promoted local strengthening of the small-size grain region, resulting in grain-scale incompatibility deformation and enhanced strain localization. The difference in the degree of deformation between the large-size and small-size grain regions accordingly became irreconcilable, which led to stress concentrations and microcrack initiation. Based on these results, it was recommended that the microstructural condition of steel brake discs be monitored during maintenance inspections and that the sliding surfaces be turned to remove the recrystallized material if necessary.

A Critical Review of Hyperloop (Ultra-High Speed Rail) Technology: Urban and Transport Planning, Technical, Environmental, Economic, and Human Considerations

Companies globally have been trying to alter existing transportation systems to maximize public transport benefits, especially in the sector of high-speed (HS) ground transportation. The latest invention of such is Elon Musk's ultra-high-speed rail (UHSR), hyperloop. This technology enables a rail service to operate at a potential speed of 1,200 km/h. Hyperloop's ambitious speed goal has the potential to result in time-space shrinkage, which would then make distant cities more accessible with greatly reduced travel times. Since 2013, several companies have been vigorously promoting hyperloop development in various locations worldwide and competing to construct the world's first functional and commercially viable hyperloop. India, a country struggling with existing public transportation and urban mobility needs, agreed to construct a hyperloop through the company “Virgin Hyperloop One.” This paper first investigates the key technical, environmental, economic and human considerations in assessing the applicability of hyperloop to a particular location. It also considers in some detail the likely urban and regional planning and transport policy implications of the hyperloop technology based on the known effects of existing high-speed rail (HSR) systems. The paper concludes that many of the claims about hyperloop are subject to contrary information, meaning that great caution and prudence are currently needed regarding attempts at commercial deployment.

Hyperloop, HeliRail, Transrapid and high-speed rail systems. Technical characteristics and cost-benefit analyses

During recent years several innovative technology systems have been conceived with the purpose to produce ever faster and more efficient transportation systems (TS) such as the Transrapid, Hyperloop and HeliRail that could provide numerous potential benefits over the traditional railways including the High-Speed Railway (HSR) system. These TS are examined from a technical point of view and are compared to each other by cost-benefits analysis. Benefits (B) and Costs (C) taken into consideration both in Financial and Economic analysis are those of each unconventional transportation system (i.e. Transrapid, Hyperloop and HeliRail) with respect to the HSR system. A case study has been considered (line length: 500 km, traffic demand: 15 million passengers for direction). The results demonstrate that from a financial point of view all the innovative TS are worse in comparison with the HSR system. The economic indicators show that the most advantageous system is the HSR because the other ones give rise to values of the Economic Net Present Value (ENPV) < 0. Alternative types of TS in comparison with HSR system are unsustainable since, for each of these, it results ENPV <0 and benefit-cost ratio B/C < 1. Sensitivity analyses of Financial and Economic indicators in function of the traffic demand levels (range 1–21 million passengers/year) and line lengths (range 100–800 km) have been carried out to identify the most appropriate transportation system for given boundary conditions. The outcomes prove that the best mass public transport system is still today the HSR, except in special cases.

Computational Modelling of the Aerodynamic Noise of the Full-Scale Pantograph of High-Speed Trains

High speed rail systems have significantly developed due to the increased demand on the rail transportation in the recent years. The necessity for enhancing the environmental sustainability of the rail systems imposed many challenges for the researchers to decrease the level of noise generated by the high speed rail systems. This paper aims to investigate the aerodynamic noise of the pantograph of the high-speed trains in different operating conditions. Computational fluid dynamics technique was used to assess the acoustic noise of the pantograph components. Three-dimensional computational simulations were performed using FLUENT software. Comprehensive analyses of the acoustic pressure and the air velocity distributions were accomplished for the detailed full-scale pantograph components. A modified model for the pantograph was introduced to reduce the aerodynamic noise of the pantograph’s panhead. Good agreement was found between the obtained results and the reported results in the literature. Different design profile for the collector was then presented as a possible solution for the reduction of both the aerodynamic noise and the reduction of the fluctuating forces at the panhead-catenary interaction, which affects the quality of the power transmitted to the high-speed train. Vortex shedding was the main source of noise at the pantograph panhead and knee. Based on the obtained computational results, it was found that the use of an elliptic-edge cross-section bars can be a potential modification in the collector shape that can reduce the aerodynamic noise at the panhead.

Perception of safety and passage of time as factors influencing mode choice: The case of the Prague-Munich high-speed route

Abstract Behavioural factors of risk perception and time perception influencing the mode choice on the Prague-Munich route in relation to railway as a reference mode, are subject to evaluation in this article. Semi-structured interviews are qualitatively analysed using the Grounded Theory method and ATLAS.ti software, giving specific sets of meanings and understandings of selected factors, which in turn affect the travel behaviours and the mode choice. Defining these factors creates space for estimating and proposing perspectives for the development of expected travel behaviours in the context of the planned high-speed rail (HSR) system on the Prague-Munich route. The significance of this research lies in creating new meaning fields of selected factors in the specific transport infrastructure with four existing transport modes between Prague and Munich. The results based on the formulated concepts show two different meaning fields of risk – the concept of perceived risk of an accident and the concept of personal safety. Empirical results of time perception show four different meaning fields of time perception based on a preferred transport mode. Finally, the results are used for creating contextual perspectives for HSR planning across Czech – German borders.

Wheel condition assessment of high-speed trains under various operational conditions using semi-supervised adversarial domain adaptation

Train wheels, among other components, are critical for the safety and ride comfort of high-speed rail systems. Various machine learning methods have been used together with onboard monitoring data to assess the wheel health conditions. However, only in some well-controlled experiments or authorized circumstances (source domain) can the well-labelled monitoring data for supervised learning be obtained. Even so, due to the difference in operational conditions, directly applying the model learned from this case to the case of interest (target domain) is not reliable. Facing this challenge, we propose an adversarial domain adaptation (DA) approach to transfer knowledge from a well-controlled monitoring test in one rail section to the rail section of interest. Since in the target domain, the data corresponding to components that are new or after reprofiling can be labelled as “intact”, the DA is modified to be semi-supervised rather than unsupervised. Two-level marginal and conditional DA is conducted in an adversarial manner, which can sufficiently eliminate the distribution discrepancy induced by the operational differences between two rail sections on which the train runs. Onboard monitoring data collected from the Lanxin high-speed rail section before and after wheel reprofiling is used as a case study. Results demonstrate the effectiveness of the approach as well as its superiority over three baseline models, and the underneath mechanisms are visualized. The study is expected to provide new thinking for the condition assessment for other key components when the train runs under various operational conditions.