The current evaluation system for the sustainable development of urban rail transit often employs a simple hierarchical weighted summation method. However, this method does not account for the interactions among indicators at the same level or the multiple effects of lowerlevel indicators on upperlevel indicators, thus failing to reflect the actual sustainable development status systematically, comprehensively, and accurately. To address this issue, this study introduces a new evaluation approachthe ESE (EconomicSocialEnvironmental) evaluation theory and method. This approach builds on the new understanding that data impacts the three dimensions of economy, society, and environment. An ESE spatial Cartesian coordinate system is constructed to represent all operational scenarios of urban rail transit. Within this threedimensional ESE space, the sustainable development status of urban rail transit is classified into "eight types and four categories," allowing for the quantification of sustainability levels and enabling a threedimensional visual representation.

Mediumand lowvolume rail transit, as a supplement to metro networks in super or mega megacities and as the backbone of large and mediumsized cities, is essential for solving urban traffic problems. Based on a survey of more than 2600 mediumand lowvolume rail transit operation lines in 496 cities in 65 countries, a database of mediumand lowvolume rail transit lines worldwide was constructed. Based on this database, 9 types of mediumand lowvolume rail transit systems (gear rail, tram, suspended monorail, automated people mover systems (APM), straddle monorails, linear motor systems, mediumand lowspeed maglev, electronic guidance rubbertired system, and beamguiding rubbertired system) have been obtained worldwide, with a total length of 18 744.84 km. And statistics were conducted on the distribution of mediumand lowvolume rail transit in various continents and countries. The results showed that it is mainly distributed in 32 countries in Europe, including Germany and Russia, with a total length of 13 256.0 km, accounting for 70.7%. Statistics show that the distribution of various rail transit systems in different countries/cities, with different urban characteristics and functional positioning of different lines shows that mediumand lowvolume rail transit systems mainly serve cities with a population of less than 3 million. 76.25% of tram lines, 47.82% of straddle monorail lines, and 42.11% of linear motor system lines are backbone lines, 84.62% of gear rail lines are tourist lines, and 70.73% of APM lines are airport dedicated lines. Additionally, the origin and development of each system are summarized, and the technical characteristics, parameters, and applicability of each system are analyzed. The results provide a reference for the selection of urban medium and lowvolume rail transit systems in China.

The optimization of slow traffic systems in urban rail transit stations improves the operational efficiency of rail transit, upgrades the spatial quality of stations, and promotes the integration of stations and cities. To provide a reference for planning theories and practical research in this field in China, based on the literature related to slow traffic systems in urban rail transit station areas in WoS and CNKI core databases, and with the aid of CiteSpace, a literature analysis tool, this paper outlines the temporal, national, disciplinary, and journal distributions, analyzes the historical development of research and identifies recent hotspots: synergy research of stations and cities, shared bicycle transfer research, and accessibility research. In addition, the current progress in four key research directions is reviewed: slow traffic accessibility, slow traffic environment, slow traffic transfer, and slow traffic facility planning. Moreover, this paper proposes future research directions that can be expanded in terms of research object, method, and scope.

The construction of dual prevention mechanisms is an important task in the safety management of urban rail transit projects. Currently, guidance in the construction of dual prevention mechanisms is deficient owing to the lack of laws and regulations, differences in the understanding and implementation of dual prevention mechanisms in various cities, and various problems in the execution process. An investigation of the current scenario of the construction of the dual prevention mechanisms revealed that the problems are primarily manifested in the mixing of phrases and terminologies, lack of safety risk management assessments, incomplete investigation and rectification of hidden dangers, inconsistent grading standards of hidden dangers, and insufficient combinations of risk and hidden danger controls. Relevant research can provide a reference for the standardization and improvement of dual prevention and control in the field of urban rail transit engineering.

In response to the integrated fare system for areas that use crossstandard rail transit payment in urban areas, based on previous literature and domestic and international research, this article first clarifies the principle of crossstandard barrierfree ticket pricing under a single path. Subsequently, the multipath crossstandard barrierfree ticket pricing schemes are divided into two categories: origin–destination (OD) differential and OD equal pricing. The technical methods of accurately tracking passengers based on the classification of ticket types used by passengers in OD pricing research are discussed, and infeasible conclusions are obtained. The OD sameprice study recommends the weighted path algorithm, which considers the revenue of revenueguarantee enterprises and the public welfare guarantee of people's travel expenses. This paper proposes two algorithms, namely the passenger flow weighted path and average weighted path, describes the calculation steps of the algorithm in detail, and verifies the feasibility of the algorithm through two examples of Guangzhou Metro. This study is the first in China to fill a gap in the country to a certain extent.

To improve the comprehensive development efficiency of land along rail transit lines, guide the orderly development of urban rail transit stations, and ensure the supporting role of urban sustainable development, we conducted innovative research on the overall strategy of comprehensive transitoriented development (TOD) in Foshan based on a toplevel design. First, we outline the practical problems encountered by Foshan City, an important mega city in the Guangdong Hong Kong Macao Greater Bay Area, in the current stage of comprehensive development of rail transit, such as the lack of interest sharing mechanisms, failure to collect and store land along the line in advance, insufficient planning and coordination of station site selection, and mismatched timing between rail construction and comprehensive development. Subsequently, a comprehensive coordination framework for reasonable development is described. Development strategies are proposed, such as improving toplevel design, strengthening strategic coordination, advancing land preparation and storage, and exploring diversified land supply. Finally, using the land use planning practice along the second phase of construction planning for an urban rail transit line in Foshan City (Line 4 Phase I, Line 2 Phase II, and Line 11) as an example, toplevel policy challenges, toplevel planning challenges (coordination of national spatial planning and comprehensive transportation planning), land challenges (land preparation and storage, diversified land supply mode issues), and TOD construction mode challenges are discussed. We explore and establish a toplevel design practice path for comprehensive development that corresponds with the characteristics of Foshan City and propose an overall strategy for TOD comprehensive development that is suitable for the actual scenario in Foshan City. This can effectively guide the implementation of comprehensive development of land around stations along the line and provide valuable toplevel design practice experience and reference basis for similar metropolitan areas.

To advance the energy conservation of subway stations, this study focused on the optimization of control strategies for ventilation and airconditioning (VAC) systems. In this study, Beijing, Shanghai, and Guangzhou were selected as representative cities for the cold, hotsummer coldwinter, and hotsummer warmwinter regions, respectively. In addition, a model of a subway station with a platform screen door system was established using a transient system simulation program (TRNSYS). The performances of automation and optimized timetable control were compared in terms of station environment, energy performance, and renovation costs. The results show that both automation and optimized timetable control can effectively improve the station air temperature during the cooling season, thereby achieving a similar station environment. Automatic control can reduce the annual energy consumption of the VAC system by 41%49% compared with the current conventional timetable control, whereas optimized timetable control can decrease the annual energy use by 38%48%. For renovation costs, optimized timetable control merely requires improvement in management without supplementing devices, whereas automatic control requires higher equipment and maintenance costs. Therefore, we recommend the adoption of optimized timetable control for subway stations to achieve energy savings.

To improve the efficiency and accuracy of urban railtransit security inspection systems, this paper designs a novel patternrecognition mode to effectively combine artificial intelligence (AI) image recognition technology with manual centralized pattern recognition. First, based on the current liquid inspection, a liquid detection algorithm is introduced to avoid the open inspection of safe liquids. Second, security products are classified according to their risk levels. Finally, AI confidence judgment, manual sampling, or necessary inspection charts are combined to determine the pattern recognition mode, which can flexibly adjust the depth of the AI intervention according to the accuracy of the AI image recognition and the requirements for pattern recognition at different stages. With the continuous improvement in the accuracy of AI image recognition, it gradually changes from an AIassisted manualbased pattern recognition mode to an AIbased manualassisted pattern recognition mode and finally achieves a fully intelligent pattern recognition mode. A case analysis reveals that the judgment graph model can further achieve rapid security inspection, cost reduction, and efficiency increase without reducing the safety inspection level of urban rail transit stations.

A switch machine is a core equipment of a signal system with the largest maintenance volume, strongest maintenance difficulty, and a wide range of equipment failures. With the increase in intelligent operation and maintenance research in the urban rail transit industry, research on intelligent operation and maintenance of switch machines has attracted the interest of industry scholars. It is the foundation for achieving intelligent maintenance of urban rail signals and intelligent operation and maintenance production organization modes. This article summarizes the limitations of traditional microcomputer monitoring systems and proposes an intelligent system based on the maintenance difficulties and pain points of switch machines in the industry. The system includes critical state perception, intelligent fault diagnosis, critical state warning, and health assessment, and proposes specific implementation methods. The system was successfully applied to Nanning Metro Lines 4 and 5, and significant benefits were obtained.

To ensure the safety of ancient buildings during subway shield tunneling, a general technical approach involving initial assessment, reinforcement, construction monitoring, subsequent evaluation, and additional reinforcement has been established. This study built a 1: 3.52 physical model of ancient buildings and conducted shaking table tests to obtain the damping ratio of structures Ansys was used to build a threedimensional model. Using structural and modal analysis for vulnerable structures for strengthening and prevention, this study provides a reference for the followup vibration monitoring and shield construction. The construction parameters were adjusted according to the construction monitoring data in the test area. The results showed that the maximum displacement of the structure was approximately 14.01 mm under static analysis, which verified the validity of the threedimensional model. The basic frequency of the structural model was 0.590 46 Hz and the most vulnerable position was sandalwood. During shield tunneling, the acceleration of ancient buildings was less than 0.003 m/s², the vibration frequency was primarily concentrated at 0.6–20.5 Hz, and the vibration frequency was in the normal range. The paper proposes that the overall solution of subway shield tunneling through the ancient buildings involves a uniform driving speed, avoiding the operation peak period, using the grouting reinforcement between the strata in the affected area, supporting the vulnerable structure of the ancient buildings, and adopting a vibration isolation and vibration reduction scheme during the construction. This provides a reference for similar subsequent projects.

In order to address the issue of longterm dependence caused by the extended time span of wheel wear data and improve the prediction accuracy, an improved BiLSTM metro wheel wear prediction model is proposed by optimizing Bidirectional long shortterm memory network (BiLSTM) with Sparrow search algorithm (SSA). Firstly, the hyperparameters of the BiLSTM algorithm, such as the number of neurons, iteration count, input batch size, and learning rate, are optimized using the SSA. This optimization process is conducted within a specified range to obtain the optimal values of these hyperparameters. This optimization process aims to obtain the optimal parameter values. Subsequently, the SSABiLSTM network model is constructed using these optimal parameter values to predict and analyze wheel wear. Tread wear and flange wear are taken as the research objects, and the measured historical wear data of wheel No.1 of the metro’s carriage # 1 are used as inputs to metro and validate the model, and compare the prediction results with those of MLP, LSTM, BiLSTM and SSA-LSTM models. The results show that the improved bidirectional long short-term memory network model has higher wear prediction accuracy, and the mean absolute percentage error (MAPE) of tread wear is reduced by 13.28%, 10.32%, and 1.47%, and flange wear by 9.5%, 0.46%, and 0.02%. The wear of the No. 1 wheel of the same metro No.2 and No.4 cars is predicted and compared with the measured wear data. The average absolute percentage error of tread wear is 1.34% and 1.42%, respectively, and the average absolute percentage error of rim wear is 0.18% and 0.19%, respectively. The results confirm that the model exhibits strong generalization capabilities. The wheel wear prediction model based on improved BiLSTM network (SSA-Bi-LSTM) has high prediction accuracy and good generalization, which provides theoretical support for the intelligent management of metro wheelsets and prolongs wheel service life.

In view of the lack of research on rescue scenarios in the operation of metro railway and the inability of the electric multiple unit (EMU) to fully meet the timeliness requirements of rescue, the runaway risk and braking strategy of metro train rescue conditions are studied. Firstly, a longitudinal dynamic model is established for the coupling of multi formation trains and then Beijing New Airport Line is token as an example to analyze the potential risk of train slip caused by the existing urban rail transit operation under rescue scenario. Finally, based on relevant standards, this study analyzes the comfort of passengers under different braking modes during the rescue process. The results show that when coupled at a speed of 5 km/h on a 33‰ slope, the acceleration and jerk rate of the train will reach 10.5 m/s² and 9.9 m/s³ while at holding brake mode, and slip will occur. However, the acceleration and jerk rate of the train at emergency braking mode decrease by 63.1% and 54.7%, respectively, and no slip occurrs. When the coupling speed is reduced to 3 km/h, the maximum acceleration and maximum impact rate are reduced to 2.1 m/s² and 2.4 m/s³, respectively, which means passenger comfort significantly improves. When the train is parked on a slope, due to the braketraction switching process, the holding brake force should reach to 60% or more of the maximum service braking force to ensure that the vehicle will not slide on the maximum slope.

Rapid urbanization and population growth have led to a continuous increase in passenger flow in urban rail transit, which presents significant challenges to the safety, comfort, and stability of rail transit operations. To solve the problem of excessive load rate of urban rail transit during peak hours, we propose a cooperative passenger flow control method for urban rail transit based on deep reinforcement learning. This method uses the full load rate between intervals as its state, a flow restriction strategy as its action, and the passenger flow experience as its reward. It generates an optimal flow restriction scheme through multiround reinforcement learning. We validated the effectiveness of this method by constructing simulation experiments using data from the Beijing subway network. The simulation results show that the cooperative passenger flow control method can effectively reduce passenger flow in a section, relieve congestion during peak hours, and improve passenger travel comfort.

To provide maintenance advice regarding a scenario in which floating slab tracks are soaked in water, we established a numerical model of a submerged steel spring floating slab track vibration based on the fluidsolid coupling theory. The vibration reduction of the floating slab track with different accumulation water depths under a running train considering the track, water, and tunnel base was analyzed. The results showed that the water under the floating slab influences the vibration reduction performance. When the depth of the accumulated water was lower than the 1/2 height of the slabside space, the effect on the vertical vibration of the tunnel increased by approximately 5 dB at a peak frequency of 63 Hz. When the water filled with the entire height of the slab side space, the vertical vibration level of the tunnel at its peak frequency of 63 Hz increased to approximately 13.4 dB, an increase of 30.7%. The insertion loss of the tunnel vibration level also increased by approximately 13.36 and 13.67 dB at 63 and 80 Hz, respectively. Therefore, when the height of the water under the floating slab was over the 1/2 height of the slab side space, which means that the vertical vibrations of the slab and tunnel at their peak value frequency were larger than 5 and 10 dB, respectively, than under normal conditions without water, maintenance work to drain away the water should be performed immediately.

The mechanical behaviors of Ushaped girders in urban rail transit differ in the spanning and transverse directions, and a dynamic coefficient of 1.40 in the current design code will result in material waste. Considering the bidirectional stressing characteristics, the Ushaped girder of the Nanjing Subway Line S6 Urban Rail Transit was selected as a case study, and a trainbridge coupling dynamic model was established. The effectiveness of the model was verified by comparing the test and calculated results. The dynamic coefficients of the different responses were analyzed by changing the train speed and formation. The results indicate that the girder bottom only bears longitudinal tensile stress but carries both transverse tensile and compressive stresses in the same section. The maximum dynamic coefficients of the deflection, longitudinal stress, and lateral stress were 1.231, 1.216, and 1.362, respectively, in the fulland fixedload cases of the 6car formation. When determining the dynamic coefficients of a singletrack Ushaped girder, the influence of the train formation should be considered, and the values should be distinguished according to the stressing directions. We recommend a value of 1.30 when calculating the deflection and longitudinal stress and 1.40 when calculating the lateral stress. This paper proposes reasonable values for the dynamic coefficients of Ushaped girders and provides a reference for structural optimization.

This study investigates the wheelrail noise characteristics of urban rail trains passing through longspan bridges, focusing on the Dongshuimen Bridge of the Chongqing Rail Transit Line 6 and the Chaotianmen Bridge of the Chongqing Rail Transit Loop Line. Noise measurement data were collected for trains passing over the bridges. This study analyzed and compared the spectral characteristics of noise, summarizing the relevant patterns. The results indicate that the wheelrail noise generated by rail trains on largespan bridges exhibits a widefrequency characteristic, with the sound pressure level spectrum curve showing a “high in the middle, low on both sides" pattern. The noise peak of steel truss arch bridges is concentrated at approximately 800 Hz, and the structural noise generates a relative peak in the range of 6380 Hz. In contrast, the noise peak of the steel truss girder cablestayed bridges is in a higher frequency range. The threespan continuous steel truss suspension arch bridge exhibits a wide and highamplitude noise spectrum, with its noise being significantly greater than that of the steel truss girder cablestayed bridge, particularly in the midto highfrequency range of wheelrail noise.

This study addresses problems of numerical methods for continuous media, such as the finite difference and finite element methods to simulate the discrete medium characteristics of a sandy cobble stratum. Based on the blockbased discrete element method, a discrete element model is built to simulate the process of shield tunneling through a sandy cobble stratum, and the displacement of joints and deformation of the surrounding rock and liner is studied. A finite difference model, in which a sandy cobble stratum is transformed into an equivalent continuous medium, is built to simulate the process of shield tunneling, and to compare the differences in simulation results between the discrete element model and the finite difference model. The results show that, in the discrete element model, the area at which the positive normal displacement of the joints exceeds 0.1 mm is primarily concentrated at the inverted arch, the area at which the negative normal displacement of the joints exceeds 0.1 mm is located at the hance, and the area at which the shear displacement of the joints exceeds 0.4 mm is primarily concentrated at the inverted arch. The simulation results of the discrete element method are greater than those of the finite difference method with respect to the deformation of the surrounding rock and liner; therefore, utilizing the discrete element method to verify the design of the tunnel and liner is relatively more secure and reasonable.

Focusing on the reuse of tunnel muck, this study aims to prepare tunnel muck from the Suzhou Metro Line 8 into a synchronous grouting material that satisfies the engineering requirements of different geological conditions by adjusting the solidification material compositions through laboratory experiments. In this project, a new doubleline shield tunnel of Metro Line 8 intersects the existing doubleline tunnel of Line 3 at Tangzhuang Station, forming a unique layout with two layers of four tracks. The muckproduced grout used in this project has a consistency value of 113 mm, and the 7and 28day strengths exceed 1 and 2.5 MPa, respectively, satisfying the engineering specifications. The deformation monitoring data show that the muckproduced grout effectively controls the impact of the upper tunnel construction on existing structures. Utilizing shield tunneling muck to prepare synchronous grouting slurry can achieve resource utilization of muck while promoting green construction and reducing construction costs by approximately 750 thousand Yuan per kilometer (double line).

In order to enhance the safety of Fully Automatic Operation (FAO) systems in urban rail transit, a hazard analysis method for FAO systems is proposed, which is based on scenario fusion from the perspective of FAO system operation and maintenance. The method initiates by identifying scenario elements and integrating them, to generate FAO application scenarios. It then comprehensively selects an allocation method of semiquantitative SIL (Safety Integrity Level) among proportional allocation, prior information allocation, and combined logical allocation, to complete the allocation of safety targets of functions of the core subsystems. Finally, the analysis method is applied in an actual engineering project case, providing a reference for subsequent hazard analysis and SIL allocation for metro lines with FAO system. This approach also addresses the limitations of traditional FMECA (Failure Mode, Effect and Criticality Analysis) in performing SIL allocation for multisystem functions.

Metro traction current changes dynamically during train operation, resulting in magneticinduced voltage in the peripheral grid circuit, which is one of the key challenges that cause transformers to undergo DC demagnetization. The generation of magnetic induction voltage is affected by various factors. To quantitatively analyze the size of the contribution of different influencing factors, this paper uses the magnetic induction voltage formula to derive the main influencing factors of the magnetic induction voltage of the subway. Subsequently, the “subway linetransmission line” magnetic coupling boundary element model is established to simulate and analyze the influence of the key factors on the induction voltage. The influence of the key factors on the induction voltage is analyzed. During the smooth running of the train, the induced voltage is not significantly affected, and at 1000 m, the induced voltage is attenuated by 90%. We constructed the backpropagation (BP) neural network to generate the magnetically induced voltage and analyzed the contribution of each influencing factor to the magnetically induced voltage using the mean impact value (MIV). The results show that the main influencing factors in the equivalent loop of the subway are the same as those in the grid, and the magnetically induced voltage in the equivalent loop is the same as that in the grid. The results show that the magnetic induction voltage in the equivalent loop is more likely to be influenced by the equivalent loop length, the contribution of which is 44.38%, and the relative distance has the smallest contribution of 21.31%. Therefore, the area of the power system constituting the equivalent loop is the most important factor affecting the magnetic induction voltage.

In response to the application problems of eCNY hardware wallets in rail transit gate boarding, business process design and ticketing system transformation methods were adopted to implement eCNY hardware wallets for the Suzhou rail transit gate boarding business. In this paper, first, the basic concept of eCNY hardware wallets is introduced, and the application forms of eCNY hardware wallets in rail transit are clarified. The current business scenario, usage needs, and technical characteristics of eCNY hardware wallets in rail transit and the overall plan for passing through gates and boarding trains with eCNY hardware wallets is determined, and a detailed design is for the registration, entry and exit, ticket processing, and other business processes of eCNY hardware wallets is described. Finally, combined with the current scenario of the Suzhou Rail Transit ticketing system, a specific transformation scheme of the Internet ticketing system and an automatic fare collection system is proposed to achieve the eCNY hardware wallet lockin service. The application of eCNY hardware wallets in Suzhou Rail Transit has a promotional significance for the promotion of eCNY hardware wallets and has a reference value for the application of eCNY in the field of rail transit.

Rapid urban rail transit growth presents new challenges for operation and management. Traditional methods limit data and resource utilization. China's "strong transportation country" strategy and smart city development necessitate a shift from traditional to digital thinking for subways, a crucial component of resident travel. Digitalization offers the potential to enhance operational efficiency and quality. This study analyzes the challenges of digital rail operations and presents Kunming Metro Line 4 as a case study. It explores Line 4's digital transformation journey, highlighting its economic benefits. By establishing a cloudbased comprehensive automation and business integration management system, Line 4 achieved synchronized digitalization across the enterprise, enabling practical implementation of digital metro operations. This approach reduced costs, improved efficiency, and offers valuable solutions for urban rail transit digitalization within the industry.

Amidst the ongoing development of rail transit and urbanization in China, station square planning with singlefunction can no longer meet the varied demands of urban construction. This study examined the construction history and related planning standards of station squares in Japan, conducted onsite research on station squares in multiple cities at different levels, analyzed the spatial planning and development methods for representative cases, and summarized the conclusions regarding Japanese station squares. The planning experience revealed the following recommendations: Pay attention to the spatial regulatory role of the station square in the integrated development of the station and city, and adjust the urban function of the square according to planning requirements. The construction of the square should be combined with the development characteristics of the surrounding areas of the station, focusing on the flexible layout and diversified use of the square. A cooperative organization should be established at each stage to focus on mutual communication and division of responsibilities among the various construction departments of the square, as well as the development of a continuous user participation mechanism and a complete square operation system, thereby hoping to provide reference and guidance for the sustainable development of China's rail transit and reasonable urban space planning.