High-speed Railway Network Research Articles

Optimization of High-Speed Railway Line Planning Considering Extra-Long Distance Transportation

Network line planning optimal considering extra-long distance transportation can adapt to high-speed railway (HSR) network operation environment and meet the demand of extra-long distance travel. First, the distance of 1500 km or more is defined as extra-long transportation distance based on market competitiveness. The difficulties of direct or transfer transportation for extra-long distance transportation are analyzed. Direct method of extra-long distance is determined according to direct passenger volume and the number of important nodes while transfer method is represented considering transfer times, organization forms, varieties of schemes, and comfort. Then, ideas of optimizing line plan based on riding scheme is put forward. Network optimizing line plan model with riding scheme is developed considering extra-long distance transportation. The model which minimizes traveling cost and train running expense optimizes train frequency and train stop plan with riding scheme. Last, the method and optimizing model is verified by the network which took Baoji–Lanzhou HSR as the core. The optimal result is a benefit to improve operation efficiency and market competitiveness of HSR.

Method for Determining the Valid Travel Route of Railways Based on Generalised Cost under the Syncretic Railway Network

Travel route options for passengers can provide data support for railway line planning, passenger flow organisation, and train operation establishment. A critical review of the literature indicates that previous studies mainly focused on choices offered by a single railway network path without much consideration of China’s normal-speed and high-speed integrated railway network and the effect of train timetable on passengers’ travel choice. In this study, a method based on generalised cost is proposed to discover the valid routes of passenger travel in the integrated network of China’s normal-speed and high-speed railways. After quantifying the effects of train fare, travel time, transfer, travel convenience, comfort, and other factors on the generalised expenses of passengers, this study presents a generalised cost determination method when individuals select an option from different seats of different trains of specific railway transport products. Theoretically, the valid routes considering the train schedule is defined, and a valid route search algorithm is designed using the deep traversal idea in a new valid route searching network. Considering the Lanzhou-Beijing passenger travel routes as an example, this study verifies the practicability of the generalised cost calculation method, as well as that of the valid routes search method.

A multi-objective programming model for timetables on corridors integrating macroscopic and microscopic approaches

This paper proposes an integrated framework for timetable design that meets the needs of service planners, who usually adopt a purely macroscopic point of view toward the demand requirements and conflicts that these timetables may cause at stations due to their particular configurations and structures. Service planners may not take these aspects into account, which require a microscopic analysis of the structure of the stations, considering possible conflicts at platforms and/or internal junctions. To this end, the proposed integrated model guarantees feasible timetables while balancing performance indexes for the interests of passengers and operators. Specified bounds are maintained for the differences between service planners optimal timetables and those that are operational at stations. The resulting problem is modeled as a multi-objective Mixed Integer Linear Programming problem. The model can be solved with sufficient accuracy and in a reasonable amount of computing time, as shown by tests on the Madrid-Zaragoza-Barcelona high speed railway network. In this case, we perform a Pareto frontier analysis and find that the problem is well-posed. In addition, the previous model forms the basis of a heuristic procedure for obtaining timetables that avoid, as much as possible, conflicts and concentrations of arrivals/departures at/from stations, thus allowing for improved timetable recoverability and robustness in case of unexpected disruptions.

A line planning approach based on harmony search for high-speed rail: From the perspective of service accessibility

Service accessibility can be used to describe the travel time of passengers between different nodes, and opportunities to get transportation services in the high-speed railway (HSR) system. Based on the traditional train line planning theory, this paper introduces the transportation service accessibility index, and propose a new nonlinear passenger train line planning model, which aims to maximize the service accessibility, as well as minimize the operational cost of railway company. The model is transformed into a single-objective model, and then we design a harmony search algorithm to solve it. Finally, the model is validated by a numerical example. The results of this model as well as the scenarios of the single-objective models for minimizing operational costs and maximizing service accessibility are compared. From the perspective of service frequency and accessibility of each nodes, we know that the proposed method can balance conflicts between average speed between large nodes and service frequency of small and medium size nodes in high-speed railway network.

High-Speed Railway EMUs’ Circulation Plan Optimization: A Two-Stage Optimization Algorithm Based on Column Generation

Considering the characteristics of China's high-speed railway network and the allocation structure of Electric Multiple Units (EMUs), the EMUs operation management mode provides an effective technical route for EMUs route planning optimization. To reduce the number of EMUs, key factors such as the EMUs mileage, time limit, maintenance model, maintenance capability, night accommodation capacity, maintenance management mode, and train tasks are considered as constraints. The number of maintenance tasks is also the objective so that the EMUs route planning solution method is more integrated with actual production needs, and an optimization model of EMUs route planning is established to overcome the shortcomings of previous studies that did not sufficiently consider EMUs maintenance. To verify the feasibility and effectiveness of the proposed model and method of the proposed two-stage optimization algorithm based on column generation, a case study on the preparation of EMUs circulation planning for the Beijing-Shanghai high-speed railway network is conducted, and the results are analyzed.

Emergency-induced effects on high-speed railway networks: A complex network theory’s perspective

In this paper, we analyze the characteristics of high-speed railway networks in the presence of emergencies from a complex network theory’s perspective. First, we represent the railway network by a graph where the nodes denote stations and the edges denote train flows. For a railway network system, the punctuality of trains and the number of trains running through stations are the two main factors for evaluating emergency-induced effects. We thus assign each edge of the graph a weight which is determined by these two key quantities. Then we propose a method to estimate the delay of trains and some metrics are introduced to analyze the properties of the railway network under disruptive events. These metrics may be also used to quantify the influences of the emergencies. Finally, examples are provided to illustrate the developed theory.

Generating Travel Plan Sets in a High-Speed Railway Network With Complex Timetables and Transfers

Developments in high-speed railways have seen them become the mainstay of passenger transport systems in China, satisfying the increasing demand for rapid access to numerous locations. In practice, the operation of the network is a vital feature of the Chinese High-speed Railway (CHR), enabling the provision of through services while allowing indirect services via major hubs. The generation of travel plan sets in a large-scale, complex high-speed railway network is an important issue, as it is the foundation and key to those travel service systems where people can inquiry about their travel plans. This paper describes a method of generating all alternative travel plans that are potentially attractive to passengers. The inherent problem is first modeled for any journey between a given origin and destination pair, and then a spatiotemporal network is constructed. For each journey, a direct set of travel plans without transfers is extracted from the train timetable data. The construction of indirect travel plans is more complicated, and a two-stage generation method is proposed: (i) compute the $K$ -shortest paths using the improved Yen* algorithm to identify transfer node(s), and (ii) connect train services according to the train timetables. Furthermore, the reliability of a specific travel plan with transfers is determined by mapping the buffer time as a reliability measure. Finally, the proposed method is tested on the CHR network using the 2019 train timetable.

Stability and Suppression Study for Low-Frequency Oscillations in Network-Train System

Electric multiple units (EMUs) have been the cause of low frequency oscillation (LFO) incidents in high-speed railway (HSR) network train systems (NTSs). In this paper a norm criterion with the advantages of simpler calculation while being less conservative than other norm criteria is introduced to analyze the stability of the NTS. A control strategy of EMU four-quadrant converters (4QCs) consisting of ac current passivity-based control (PBC) and dc voltage sliding mode variable structure (SMS) control, i.e. PBC-SMS, is proposed for LFO suppression. The NTS stability analysis with PBC-SMS results in superior critical LFO condition. A single EMU simulation validates the improved steady-state and dynamic performance of the PBC-SMS compared to other conventional methods; NTS simulations based on field tested network parameters verify the superior LFO suppression capability of the proposed method. Finally, guidelines for LFO suppression are recommended based on a comprehensive sensitivity analysis of the traction network, 4QC circuit and controller parameters of an NTS.

Research on the Maintenance and Management Mode of High-speed Railway Infrastructure in China

China has preliminarily built a modern high-speed railway network, and the huge scale of the network has put forward higher requirements on infrastructure maintenance and management. In order to achieve high quality and efficient development of high-speed railway, this paper conducts research on the maintenance and management model of China's high-speed railway infrastructure. This article describes the characteristics of infrastructure maintenance management in developed countries of high-speed railways such as Japan, France and Germany; summarizes the technical characteristics of China's high-speed railways and analyzes the factors influencing infrastructure maintenance management in China. Based on the theory of organizational structure, the article systematically analyzes the differences in the work content, work methods, and means of high-speed railway infrastructure inspection and monitoring, routine maintenance, and specialized repair operations, so as to put forward the maintenance management mode of the separation of "inspection, maintenance, repair". This model mixes together the specialization of technical management and the comprehensive integration of production organization. On this basis, a comprehensive maintenance system for high-speed railway infrastructure was designed and a comprehensive maintenance organizational structure and working mechanism was proposed. Practice has shown that a comprehensive maintenance system for high-speed railway infrastructure is conducive to improving emergency response capabilities, reducing operating costs and achieving optimal resource allocation.

Site selection of high-speed railway station: A trapezoidal fuzzy neutrosophic-based consensual group decision-making approach

The need of quick and comfortable public transportation in our societies makes that many countries are planning to develop a high-speed railway network for improving their passenger transport capacity. Such a development implies among other problems how to select the location of high-speed railway station (HSRS) in each city along the line? Thus, this paper introduces an integrated approach for solving the site selection problem of HSRS, which consists of a consensus reaching process (CRP) with a group decision making (GDM) method whose inputs are trapezoidal fuzzy neutrosophic set to model experts’ assessments of potential locations of HSRS. To accomplish the decision process, the inputs should be weighted and aggregated with novel trapezoidal fuzzy neutrosophic prioritized aggregation operators to reflect the priority relationship between the aggregated information. The necessity of polishing conflicts in these decisions lead then to improve the experts’ agreement in the group, in our case, three consensus indexes at different levels are defined to implement the CRP. Eventually, the proposed CRP-GDM approach is put forward to solve the site selection issue of HSRS and a case of study is presented to illustrate its applications and advantages.

Impact of Beijing-Guangzhou High-speed Rail on Capital Accumulation in Cities Along the Line

The development of transportation has triggered regional element flows by changing the location conditions of cities along the route. In recent years, with the full implementation of the National Medium and Long-term Railway Network Plan, China’s high-speed railway network layout has continued to expand, and high-speed rail has become an important means of transportation for people. The development of high-speed railways will definitely have a wide-ranging and far-reaching impact on the concentration of elements along the route. This article takes the Beijing-Guangzhou high-speed rail as an example, adopts the matching idea as the high-speed rail experimental group to match the control group, and estimates the impact of high-speed rail on the accumulation of capital factors by constructing a double difference model. The results show that the completion of the Beijing-Guangzhou high-speed rail has made a significant contribution to capital agglomeration.

Chinese High-speed Railway: Efficiency Comparison and the Future

High-speed railway (HSR) network building was initiated in China in the early 2000s, and full-scale construction began several years later as a larger use phase started in 2008. Thereafter, the expansion speed has been impressive. Network investment could be considered as a success, if evaluating the amount of high-speed railway usage already during the expansion phase. The diffusion models built in this research show that expansion in the network and growth of the passengers will continue at least until the following decade. The performance is evaluated in terms of DEA efficiency model. It is shown that efficiency started from very low levels, but it has been increasing together with the expansion of HSR network. Currently, the efficiency is near the level of the leading European High-speed (HS) countries (Germany and France). However, it is projected with linear model and by Bass diffusion models that the efficiency will reach Japanese and South Korean standards in the next decade. A somewhat larger network length with smaller relative growth of passengers, but with a higher growth of passenger-km seems to be able to reach even the frontier efficiency.

High-speed railway, market access and economic growth

This paper establishes a general equilibrium trade model, adopts the “market access” approach to measure the impact of the high-speed railway (HSR) network on the economic growth of 110 main Chinese prefecture-level cities, of which we manually collected the pairwise travel distances and railway speeds to calculate MA (Market Access). The empirical results show that the launch of HSR exhibits significant positive effects on growth, specifically, 1 percentage increase in MA leads to an increase of real income by 0.123 (controlling region fixed effect) or 0.121 (controlling province fixed effect) percentage. Counterfactual econometrics analysis shows that if all HSR were removed in 2015, the market access would fall by an average of 76.2%, and aggregate real income would decline by up to 9.4%. The growth effect of HSR varies across cities, and HSR has a more prominent impact on services than on manufactures. The conclusion stands valid after a series of robustness tests.

Temporal Variation of Ground-Borne Vibrations in Ballasted High-Speed Railway Embankments

The ascending requirement of railway passengers for fast transit to distant stations has led to the development of high-speed railway networks. Faster and longer trains with heavy axle loads are in operation, inducing stronger ground vibrations in the supporting railway infrastructure. The conventional design of railway track structures are based on the maximum displacements safely allowed in the track under the expected railway loads. However, the vibrations generated in the tracks due to railway operations should also be of concern. This study characterizes the peak particle velocities (PPVs) generated in the component strata of a ballasted railway embankment during high-speed train transit within 160 to 200 km/h. The transient response of each strata is characterized for transit of wheel load in the vibration influence zone, and temporal variation of PPVs have been logged for the transit of wheel load through a distance of 30 m on the railway track. The results from the present study indicate that railway track embankments are subject to strong ground motions during high-speed train transit, which will lead to accelerated degradation of the track structure. Ground vibrations are remnant in the railway embankment, even after passage of train wheels to farther distances. Deployment of vibration mitigation measures are recommended in sensitive locations proximate to railway lines. The particle velocities quantified in this study can be utilized by railway design authorities for estimating ground-borne railway vibrations under multiple train wheel configurations, based on the axle spacing, bogie spacing and the depth of the track under consideration.

Mission-critical user priority-based cooperative resource allocation schemes for multi-layer next-generation public safety networks

The Republic of Korea became the first country in the world to have next-generation long term evolution (LTE) public safety networks, and South Korea’s evolution in critical communications has taken the lead as well. However, the same 700 MHz frequency band is allocated to the LTE-based public safety (PS-LTE) network, the LTE-based high-speed railway (LTE-R) network, and the LTE-maritime (LTE-M) network, and hence, extensive interest and practical research into co-channel interference management schemes are immediately required. This paper focuses on multi-layer next-generation public safety networks and employs efficient mission-critical user priority-based resource allocation schemes to resolve major challenges, such as co-channel interference, mission-critical user requirements, quality of service (QoS) prioritization, etc. We utilize coordinated scheduling (CS), coordinated multipoint (CoMP), and intercell interference cancellation (ICIC) under the radio access network (RAN)-sharing environment to analyze the overlapping next-generation PS-LTE, LTE-R, and LTE-M networks. CS CoMP is implemented between the three LTE public safety networks to boost cell-edge-user performance by muting the neighboring interfering base stations. This accomplishes a tremendous enhancement in system throughput for coexisting next-generation public safety networks. By employing ICIC with CS CoMP under the RAN-sharing environment, the best interference and outage performance can be attained for coexisting PS-LTE, LTE-R, and LTE-M networks.

Stability of a train running over the Volga river high-speed railway bridge during crosswinds

A study regarding the safety against crosswinds of a high-speed train running over a railway bridge belonging to the future high-speed railway network in Russia is presented. The dynamic analyses are performed using a software named VSI - Vehicle-Structure Interaction Analysis developed by the first authors. The wind load is applied to the bridge and train using a practical methodology based on a discrete gust model, thus avoiding the generation of complex stochastic wind models. The dynamic response of both the bridge and train is assessed and the running safety criteria evaluated. Two different bridge structural solutions have been proposed by the designer. Therefore, the results obtained on these two structural solutions are compared and the limit values for the train speed for each analyzed wind speed are defined based on the running safety criteria allowances defined in the codes.

A branch-and-price approach for trip sequence planning of high-speed train units

In high-speed railway operations, a trip sequence plan is made once the timetable is determined, and serves as a reference in the subsequent operations of train units scheduling. In light of the maintenance requirements of train units and periodicity characteristics of trip sequences, we introduce a trip sequence graph to describe the train units’ movement and coupling/splitting in a railway network. Based on the trip sequence graph, two integer linear programming models are then formulated, namely a path-based model and an arc-based model. Integrated with the characteristics of the trip sequence graph, a customized branch-and-price algorithm is developed to solve the path-based model. The two models are applied to the high-speed railway network in eastern China, and through numerical experiments, the effectiveness and applicability of the models are discussed.

Research on the Influence of Shanghai-Kunming High-speed Railway on the Economics of Cities along the Line Based on Optimized Gravity Model

With the continuous growth of the demand for inter-regional personnel exchanges between modern social and economic development, high-speed railways, as a modern means of transportation that combines various high-tech, play an important role in meeting the high demand for mobility among regions and promoting social development. Among them, Shanghai-Kunming high-speed railway, as an important part of China’s high-speed railway network, deserves in-depth study. In this paper, the city quality is obtained by comprehensive evaluation of cities along the line by entropy method. The time distance is used to replace the spatial distance. The gravitational model of the city is optimized, and the gravitational change between cities along the line before and after the opening of the Shanghai-Kunming high-speed railway is more scientifically described. Finally, the paper proposes that the opening of the Shanghai-Kunming high-speed railway can effectively promote the economic development of cities along the line, especially the rapid rise of western cities.

When High-Speed Railway Networks Meet Multipath TCP: Supporting Dependable Communications

Multipath TCP (MPTCP) is an extraordinarily promising technology to guarantee service dependability in high-speed railway (HSR) networks. However, the phenomenon that wireless losses caused by frequent handoffs or other non-congestion losses in HSR networks has a detrimental influence on the performance of MPTCP. In order to improve performance of MPTCP when Long-Term Evolution for Railway (LTE-R) and WiFi communication routes are aggregated in HSR networks, we present a novel congestion control scheme, i.e., RVeno in this letter. Simulation results clearly reveal RVeno outperform the existing MPTCP congestion control algorithms in terms of throughput.

Evaluation on the Use of Italian High-Speed Rail to Support Transportation Network for Transplantation Activities

BackgroundOne of the main activities connected with transplantation is the rapid and timely transportation of patients, medical teams, and human organs from donation to transplantation centers under the compliance of national guidelines and principles of quality, performance, and safety. High-speed transportation on a railway network is becoming relevant both in terms of performance and extensiveness of the service. Methods and ObjectivesOur study explores the feasibility of adopting a high-speed rail network for the transportation of those organs with large cold ischemia time and those less influenced by transportation-related perturbations (ie, temperature, speed, vibrations), assessing savings and relative performance improvement. In this study, only kidneys have been considered; the transplantation database has been integrated with the national high-speed railway network and timetables. A function is implemented that allocates to air transportations those records with 1 of the 2 ends situated on islands, remote regions, and abroad, while rail transportation is preferred where constraints on capacity and compliance with cold ischemia time are met. Road transportation is still feasible for those records involving 2 adjacent regions and for intraregional transportation. ResultsThe opportunity of integrated road-rail transportation in place of air or all-road transportation allows users to lower generalized costs and reduce driven distance for personnel and vehicles allocated to a regional transplantation center’s fleet and staff. Savings in fleet and staff usage can serve to improve the performances at the local level. ConclusionsThe knowledge and analysis of transportation alternatives for human organs with less stringent safety and preservation criteria allow a more efficient allocation of resources both at the local and national level—without compromising quality and reliability of the system.