Tourism has become a major pillar of the national economy, and the integrated transport-tourism development model is steadily taking shape. Despite its inherent advantages, tourism rail transit still faces multiple constraints. This study therefore evaluates its current stage of development. Drawing on non-exhaustive data, it catalogs the principal completed, under-construction, and planned tourism rail transit projects nationwide. By the end of 2024, 23 projects had been completed, 10 were under construction, and 38 were in the planning pipeline; the 33 completed and under-construction lines together extend approximately 621.86 km, comprise 265 stations, and represent an aggregate investment of about 72 billion yuan. The analysis identifies four core challenges: unclear functional positioning, protracted and fragmented approval procedures, elevated construction costs, and underdeveloped technical standards and specifications. In response, the study advances targeted strategic recommendations. The findings offer a decision support reference for evidence-based planning, financing innovation, and the efficient implementation of tourism rail transit projects.

Addressing the critical challenges in constructing a data security protection system for intelligent rail transit, this paper systematically reviews recent research advances in this field. First, it examines the characteristics of rail transit data, including its multi-source heterogeneity, high real-time demands, and strong sensitivity, along with the primary security risks during data transmission, storage, and processing. Second, it explores the current application status, suitability conditions, and performance metrics of cutting-edge protection technologies—such as federated learning, lightweight encryption, and dynamic access control—against threats like cyberattacks and data breaches in resource-constrained rail transit environments. Finally, it identifies key future research directions, including AI-empowered active defense and cross-system collaborative governance. The findings demonstrate that federated learning effectively resolves data silo issues while enhancing model training efficiency under privacy guarantees. Lightweight encryption algorithms demonstrate millisecond-level response advantages in wayside equipment, exhibiting significant application potential and representing a major future development trend. The research outcomes provide both theoretical underpinnings and practical guidance for building an efficient and reliable intelligent rail transit data security protection system.

Existing evaluation approaches for urban rail transit predominantly focus on station-level analysis, lacking comprehensive consideration of the integrity and coordination at the corridor scale. This paper took Guangzhou's Metro Lines 2, 3, and 5 as empirical research objects, and extended the conventional node-place model from the station level to the corridor scale, aiming to better capture spatial dynamics along metro lines. The methods of Kernel Density Estimation and Corridor Balance Quantification were put forward to systematically assess the equilibrium status and development potential of stations along these corridors, and proposes tailored optimization strategies for each. The results reveal that Line 2 exhibited a “dependent” state overall, with both node and place values relatively low; Line 3 showed an “unbalanced node” state, featuring significant transportation advantages but underdeveloped place value; Line 5 approached a balanced state, with relatively coordinated development between node and place values. The study emphasized the necessity of integrated “corridor-station” dual-scale analysis to holistically evaluate future development needs and potentials along rail transit corridors. The results provided valuable references for formulating differentiated development strategies tailored to various rail transit corridors.

Train scheduling optimization, as a core issue in urban rail transit transportation organization, is crucial for enhancing the operational efficiency and service quality of rail transit systems. To systematically review the research progress in this field and promote its further development, this study conducts a comprehensive survey of relevant literature from both domestic and international sources. From the perspective of mathematical modeling, the paper summarizes the core elements of train scheduling optimization, including objective functions and constraints, from both the line-level and network-level perspectives. Furthermore, a detailed review of solution methods is presented, categorizing the approaches into heuristic algorithms and exact algorithms. Finally, the paper identifies existing research gaps and proposes future directions, including the need for improved modeling of dynamic passenger flow and behavior patterns, optimization of operations under network interconnection scenarios, exploration of multi-strategy operational models, and the integration of intelligent optimization algorithms, to further advance research on train scheduling optimization in urban rail transit.

This study investigates a flexible marshalling mode to address the pronounced temporal-spatial imbalance of passenger flows in urban rail transit, achieve a more precise matching between supply (capacity) and demand (ridership), and thereby reduce operating costs. A comprehensive analysis is conducted on the current state of research on flexible marshalling, its passenger-flow adaptability, and engineering implementation requirements; using Qingdao Metro Line 5 as a case, the study further structures the online coupling/decoupling workflow and examines train operation routing design, fleet allocation strategy, track layout requirements, capacity evaluation, and life-cycle operational economic benefits. Results show that online coupling/decoupling is best located within the track arrangement zones of turnback terminals and junction stations, and that configuring terminals with paired turnback sidings increases turnback capacity. Additional capital expenditures attributable to the flexible mechanical marshalling mode are dominated by rolling stock and signalling systems, which together account for approximately 90%; it is therefore recommended that civil works reserve the necessary interfaces (e.g., for track layout adjustments and platform screen doors) during initial construction. Compared with an all-6-car fixed formation baseline, a mixed operation pattern comprising conventional 6-car fixed formations and 3+3 flexible coupled sets yields superior cost effectiveness through notable reductions in traction energy consumption and maintenance costs; nevertheless, current deployment remains constrained by limited system capacity, higher marginal equipment investment, and increased operational management complexity, all requiring further optimization. The findings provide a technical and organizational reference for designing train operation schemes on comparable urban rail lines.

Ningbo's urban rail transit system faces the challenge of making more efficient use of limited corridor resources, prompting a study on express-local operation technology for Line 6 to enhance operational efficiency. The technical and economic rationale for adopting an express-local operation pattern on Line 6 was evaluated by examining technical principles, travel demand and operating schemes, selection of overtaking stations and track layouts, and time efficiency and economic benefits. Results indicate that adopting the express-local operation pattern on Line 6 meets the planned goal of a “30-minute travel circle covering Ningbo's six districts,” confers clear competitive and economic advantages, reduces travel time by about 6 minutes per trip for commuter express trains and 12 minutes for super-express trains, and generates an estimated annual social value of approximately 48.2 million yuan from passenger time savings.

To address the challenge of accurate fine-granularity passenger flow prediction and decision support in urban rail transit, the study analyzes spatiotemporal passenger flow patterns and influencing factors using automatic fare collection (AFC) data, and employs a support vector regression (SVR) model whose parameters are optimized by a particle swarm optimization (PSO) algorithm. Using October 2021 data from Beijing Metro Line 4 at a 15 min aggregation interval, weather, time period, and date type were used as input variables; model accuracy was evaluated via mean squared error (MSE), mean absolute error (MAE), coefficient of determination (R²), and relative accuracy, together with comparative model experiments. The results demonstrate that the proposed model effectively captures the spatiotemporal characteristics of rail transit passenger flow and achieves high prediction accuracy, with a mean squared error of 0.0164 and a coefficient of determination of 0.93. Additionally, a positive correlation is observed between the volume of rail transit passenger flow and error values of different model predictions. The study enhances understanding of the distribution and evolution of urban rail transit passenger flows and supports optimization of operations organization, scheduling strategies, and network planning.

To address multi-factor subway line passenger volume forecasting needs, 12 influential features are selected (time, weather, network scale, urban development, holidays, and events) via feature mining and correlation analysis, and—targeting the difficulty of XGBoost hyperparameter tuning—a hyperparameter optimization approach based on the Zebra Optimization Algorithm (ZOA) is proposed. An XGBoost-ZOA integrated forecasting model is developed, a cross-validation scheme tailored for time-series prediction is designed, and a case study is conducted using Xi'an Metro data. The ZOA-optimized model achieves a MAPE of 3.85% on the Line 1 test set; compared with representative intelligent optimization algorithms, it yields the best performance, confirming the algorithm's superiority. Across nine lines, the XGBoost-ZOA model attains an average MAPE of 5.18%, with the maximum error below 7%, and the predicted and actual curves show a high degree of agreement. Compared with SARIMA and LSTM, the MAPE decreases by 17.8% and 21.9%, and the RMSE decreases by 10.8% and 13.6%, respectively. Finally, using feature importance, the nine lines were grouped into three categories: trend-driven, holiday/activity-driven, and multi-factor balanced passenger flows. Lines dominated by holidays/activities exhibit larger prediction errors, whereas those governed by periodic trends show smaller errors, confirming the model's interpretability and practical utility.

Accurate, comprehensive assessment of the spatiotemporal alignment between supplied capacity and dynamic, multidimensional passenger demand is essential for deploying capacity more effectively and alleviating load imbalances across the network. This study evaluates capacity-demand matching in urban rail transit from two dimensions—transport capacity supply and passenger service quality—by incorporating not only capacity utilization but also key passenger-oriented indicators (e.g., waiting time, crowding). A three-tier (station-segment-line) evaluation framework is established, and a composite assessment model is developed that integrates combined weighting (AHP-entropy) with the TOPSIS ideal-solution approach to quantify overall line-level performance. An empirical case using operational data from a Beijing Metro line verifies the model's accuracy and practicality and yields targeted optimization recommendations.

To address the issues of reduced network transport capacity and increased operational safety risks caused by large-scale passenger stranding when unidirectional service interruptions occur on urban rail transit lines, a train rescheduling model based on virtual coupling technology is constructed, and the optimization model is utilized to characterize the train rescheduling process under virtual coupling technology. A hybrid two-layer simulated annealing-genetic algorithm is employed to solve the problem. Finally, taking a case of unidirectional disruption in a city's subway line as an example, the feasibility and effectiveness of the proposed strategy are verified. The results demonstrate that compared with the traditional reverse operation strategy, the reverse operation strategy under virtual coupling technology reduces passenger total waiting time by 16.4%, passenger waiting time at stations by 14.1%, and significantly decreases the number of stranded passengers. Moreover, the flexibility and efficiency of train operation adjustments are substantially enhanced. The findings provide a modeling and optimization approach for train rescheduling under similar operational disruption scenarios.

With the background of transit-oriented development (TOD), urban underground complex structure is often joint constructed with a subway tunnel. However, the running trains in tunnel can also induce vibration responses of the underground complex, which may have negative effect on the functional use of the structure. To address this issue, a three-dimensional nonlinear soil-structure finite element model of the “Galaxy One Mile” underground complex in Changchun was developed and coupled with a vehicle-track dynamic sub-model to perform time-history analyses under subway train loading. Time history analyses on the vibration of the large underground complex were conducted, under the subway train load. After the effectiveness of the modelling method was verified through the in-situ measurement results, the interlayer and transversal vibration responses of the underground complex were acquired. Results show that train-induced vibrations propagate upward along walls and columns and then spread and attenuate horizontally through each floor slab, the columns and adjacent zones with the smallest horizontal distance to the track centerline exhibit the largest vibration responses on each floor; whereas in regions far from the vibration source, slab responses become more critical. The findings provide a reference for the development and design of underground space.

To address the technical challenges of the synchronous close-proximity construction during the shield tunneling of Line 1 of the Dongguan Rail Transit in Guangdong Province, an analysis was conducted on the impact of the construction sequence of the shield tunnel and the intermediate ventilation shaft. A construction plan was proposed that would minimize impact and maximize economic benefits. Based on the actual site conditions, three construction plans were put forward: (1) involves constructing the ventilation shaft after the shield has passed through, (2) involves the shield passing through after the construction of the shaft's base slab is completed, (3) involves the shield passing through after the main construction of the shaft is completed. Through numerical simulation, the impact of different construction schemes on surface vertical displacement, wall-top horizontal displacement, wall-top vertical displacement, and support axial force was analyzed. From the perspective of impact and economic benefits, the optimal construction plan has been determined. Finally, the impact of the selected scheme and the reliability of numerical simulation were verified through field monitoring data. The research results indicate that the surface settlement and structural deformation are minimal after the main construction of the air shaft is completed and the shield machine passes through, although the construction period is longer. After the completion of the air shaft base slab construction, the construction period for the shield machine to pass through again and for the air shaft construction to be carried out after the shield machine passes through are similar, but the surface settlement and structural deformation are smaller after the shield machine passes through again following the completion of the air shaft base slab construction. This option also has higher economic benefits and is the preferred construction plan. The results of on-site monitoring indicate that all monitoring data are within the controlled range, the selected construction plan is safe and feasible, and the impact of construction is minimal. The measured data were in good agreement with the numerical results, validating the reliability of the theoretical conclusions. The findings provide valuable reference for similar engineering projects.

In order to evaluate the safety impact of shield tunneling under close range on existing bridge pile foundations, this article focuses on a practical project and studies the influence of shield tunneling on the deformation of the lower structure of the bridge, the disturbance degree of a single pile, and the bearing capacity of the pile foundation in the vicinity of the bridge pile foundation area, especially when operating within a range of 3.0 meters from the pile foundation and crossing directly below it. The study adopts a combination of on-site monitoring and numerical simulation to systematically analyze the response characteristics of pile foundations during shield tunneling construction, and evaluates their impact in different zones based on the degree of disturbance. The results show that: ① When the shield tunneling machine excavates in the moderately weathered limestone layer with a horizontal clearance of 0 m, the induced single pile stress disturbance is significant, and the impact level is “strong impact”; ② When tunneling in strongly weathered limestone layers, due to insufficient residual bearing capacity of the pile foundation, the impact level within a horizontal distance of 3.0 m and a vertical range of 1.0~3.0 m is classified as “strong impact”; ③ When the rock embedding depth of the pile foundation is 1.0, 2.0, and 4.0 meters, significant single pile stress disturbances occur, and the impact level is also “strong influence”. The research conclusion can provide theoretical basis and engineering reference for the safety assessment and construction risk control of the interaction between shield tunnels and bridge pile foundations in similar projects.

To address the technical challenge of balancing pile foundation treatment efficiency and structural safety during shield tunneling beneath urban viaducts, this study focuses on key issues of shield cutting pile groups in mudstone strata, taking the Sichuan Normal University-Jiaozi Overpass section of Chengdu Rail Transit Line 13 as the engineering background. Through innovative cutter selection and construction control technology, a comprehensive shield pile-cutting solution that balances construction efficiency and structural safety has been developed. Combining theoretical analysis with numerical simulation, parameters such as the front angle, blade angle, and blade width of shell cutters were optimized. The research results indicate: ① A composite cutterhead with 6 panels +6 spokes, equipped with double-edged shell cutters featuring -45° front angle (zero back angle), 90° blade angle, and 10 mm blade width, significantly improves shield pile-cutting effectiveness; ② The optimized tool arrangement combining disc cutters, scrapers, shell cutters, and pre-cutters, along with shield machine system improvements and construction control measures, achieves optimal pile-cutting performance; ③ Field monitoring shows maximum pile-top settlement of 2.81 mm and post-stabilization settlement of 1.75 mm, with 76.3% of discharged reinforcement bars shorter than 750 mm and 70.1% showing clean-cut fractures, demonstrating reasonable cutter layout that effectively severs most reinforcement while minimally impacting pile-top settlement. These findings provide valuable references for shield pile-cutting methods in complex strata.

A new ballasted track rail fastening system has been developed to address the problems of environmental pollution, harm to the health of construction personnel, low efficiency, screw spike misalignment, and difficulty in ensuring anchoring quality in the construction of prestressed concrete sleeper fasteners for traditional ballasted track beds using sulfur cement mortar anchoring. The system incorporates an embedded composite sleeve within the sleeper, eliminating on-site sulfur-mortar anchoring or embedded nylon sleeve solutions. This yields a more environmentally friendly and efficient process; its simple structural design and easy operation enhance installation workmanship, reduce environmental burden, improve installation quality and productivity, and extend service life. Under the background of the increasing emphasis on green construction and high-quality development in domestic rail transit construction, this technology has a very broad market prospect.

To mitigate the risks of device impersonation and information eavesdropping faced by urban rail transit safety equipment in open network environments, this paper proposes a system scheme for lightweight Public Key Infrastructure (PKI) based on domestic cryptographic algorithm (SM algorithm), which takes into account the certificate issuance scheme for administrative management needs. First, based on the characteristics of urban rail transit, a hierarchical X.509 certificate system signed with the SM2 algorithm was designed. Then, leveraging the public key information embedded in the certificates, a three-way handshake protocol was proposed to achieve session key negotiation in a fully open network environment. Finally, communication procedures for intra-domain and inter-domain device handshakes were constructed, and their performance (efficiency) was analyzed. The results show that the proposed system still ensures point-to-point encrypted communication between devices even if all inter-device communication data are fully exposed. The device-to-device key negotiation takes approximately 214.5 ms under average conditions and about 2557.5 ms in the worst case; both values are far below the duration of the communication overlap zone when a train transitions between regional control centers, thereby ensuring acceptable efficiency.

In order to study the necessity of setting up piston ventilation ducts in metros in China's severe cold regions, this article selects typical station public areas and section tunnels of the operating Shenyang Metro Lines 1 and 9, and tests their temperature, carbon dioxide concentration, and inhalable particulate matter concentration under open ventilation operation in the hottest month and closed ventilation operation in the coldest month; utilizing temperature as an indicator of the thermal environment, carbon dioxide concentration and inhalable particulate matter concentration as a measure of air quality, this research quantitatively analyzes the actual environmental control effect of the open ventilation system of the full-height non-enclosed platform doors in operating Shenyang Metro lines on the typical stations public areas and section tunnels. The findings suggest that the piston ventilation volume formed by the open ventilation system of the full-height non-enclosed platform doors in the Shenyang Metro within the section tunnels has exceeded the amount required for temperature control, indicating that the actual regulating capacity of the piston ventilation ducts on the thermal environment of the section tunnels is relatively weak; after closing the piston ventilation duct, the thermal environment and air quality can still meet the design specifications; for future metro lines in Shenyang, it may be advisable to eliminate the piston ventilation ducts (shafts) as an optimization design scheme of the piston ventilation system; the elimination of piston ventilation ducts (shafts) has no impact on the safety of ventilation mode in station public areas and tunnel sections under both normal and emergency operating conditions. The research results in this paper can serve as a reference for the optimal design of piston ventilation systems in metros in other cities located in severe cold regions in China.

To address the difficulty of directly monitoring fatigue damage in bogie-end suspension components caused by vibration during long-term service, this study takes a track inspection device as an example to analyze its fatigue failure mechanism and proposes an indirect fatigue stress monitoring scheme based on deep learning. Hazardous measurement points were identified via finite element analysis, and data on vibration acceleration at the frame end and component stress were collected through field line tests. Three temporal regression models (RNN, LSTM, and TCN) were constructed to establish the mapping relationship between acceleration loads at the frame end and component stress. The attention mechanism was introduced to optimize model performance. Experimental results demonstrate that all three models effectively predict stress, with the LSTM model incorporating the attention mechanism (LSTM-Att) achieving the highest prediction accuracy. Validation on six stress measurement points of the track inspection device confirmed that LSTM-Att exhibits excellent predictive performance in both the time and frequency domains. This proves the effectiveness of the proposed method and offers a novel approach for monitoring fatigue damage in frame end-suspended components.

In response to issues such as complex wiring in traditional platform screen door control systems, difficulties in daily maintenance of relays, challenges in troubleshooting, and cumbersome intermediate transmission links in interactions with signaling systems, this paper proposes a platform screen door controller (PSDC) solution. This solution employs SIL4-level safety technology based on domestically developed hardware and software, along with a “fail-safe” all-electronic single-board technology, achieving a fully electronic design for the platform screen door controller. By integrating computer and network technologies, the solution realizes the integration and digitalization of interfaces between the signaling system and the platform screen door system. Comparative analysis between the traditional platform screen door control system and the proposed solution in terms of system architecture, control links, and engineering implementation reveals that the fully electronic design of the platform screen door controller features a simpler overall architecture, real-time fault detection and alarm capabilities, and eliminates inherent safety hazards associated with relay-based control circuits, significantly enhancing system safety, reliability, and availability. The proposed solution not only simplifies the debugging process for the coordinated operation of train doors and platform screen doors but also significantly reduces the information exchange time for onboard train door opening/closing upon station arrival by approximately 4 seconds, thereby improving the operational efficiency and headway of the entire line. The research findings can serve as a reference for the development of multi-dimensional integration in urban rail transit.