To promote “four-network integration” of rail transit and better support the development of urban agglomerations and metropolitan areas, this study deeply analyzes the connotation and characteristics of the “four-network integration” and summarizes its role and significance. On this basis, the study systematically reviews the four-network integration planning practice of Guangzhou's rail transit and proposes recommendations from the aspects of top-level design, operational organization, and institutional mechanisms. The research results indicate that to achieve high-quality four-network integration, it is essential to firstly establish a rail functional hierarchy system suitable for metropolitan area development based on its spatial scale, central system, and passenger flow demand. Secondly, for a certain direction of passenger flow corridor, it is necessary to fully consider the characteristics of passenger flow demand, and study the reasonable configuration of different lines within the same channel from the perspective of leveraging the advantages of various levels of track functions. Thirdly, the appropriate network integration method should be selected from a holistic perspective, balancing demand and cost while considering the applicability of interconnectivity and hub node transfers. Finally, efforts should be made to promote mutual trust in security checks and interoperability of ticket systems to facilitate passenger travel.

Ensuring financial sustainability through financial digital transformation constitutes an urgent requirement for urban rail transit enterprises, with business-finance integration serving as an effective enabler for such transformation. Addressing existing research gaps—where digital transformation studies in the rail transit industry predominantly focus on technological applications in specific operational scenarios but lack systematic financial digital transformation frameworks, while business-finance integration research lacks empirical validation in rail transit contexts and emphasizes unidirectional approaches—this study employs a case analysis methodology examining Guangzhou Metro's practical implementation to investigate pathways and outcomes of bidirectional business-finance integrated financial digital transformation. That findings demonstrate that synergistic advancement of conceptual/systemic reforms, methodological transformation, and ecological restructuring effectively promotes organizational integration, information integration, and value convergence between business and finance functions, yielding significant outcomes: enhanced accounting information quality, development of cross-functional finance talent, strengthened business support, and deepened strategic alignment; financial processing efficiency improvements are manifested in a 5-day reduction of month-end closing cycles, 44% increase in per capita transaction document processing volume, and 52% rise in per capita voucher creation volume; cost-effectiveness is demonstrated through an 8.6% labor productivity gain and 9.2% reduction in cost-to-revenue ratio; the pathway “top-down design leadership→bidirectional business-finance integration→ enhanced data governance→phased ecosystem synergy” proves effective in advancing financial digital transformation. This research establishes a theoretical framework and practical paradigm for urban rail transit enterprises to advance financial digital transformation.

To address technical challenges in capacity configuration, safety design, energy management, and energy-saving evaluation for urban rail transit regenerative braking energy utilization systems, this paper proposes the new-generation stored regenerative braking energy utilization system, eRAM. We develop: (1) capacity optimization model and algorithm based on parameter decomposition; (2) a multi-level safety architecture considering rail transit application scenarios; (3) an interval energy dynamic allocation algorithm based on key parameter identification; (4) distributed cooperative control strategy based on deep reinforcement learning; and (5) data-driven condition monitoring and life prediction of energy storage components based on data driven. We present the basic principles and key technologies of each major component and evaluate their demonstration performance on the Beijing Metro Batong Line, providing a useful reference for advancing regenerative braking energy recovery and utilization in urban rail transit.

In view of the numerous controversies surrounding urban rail transit Public-Private Partnership (PPP) projects, this paper analyzes the main problems faced by PPP projects during the operation period of such projects. To ensure the stability of urban rail transit operations during the operation period and safeguard the interests of all investors, three feasible solutions are proposed from the government's perspective, with an analysis of their implementation processes as well as their respective advantages and disadvantages. The research concludes that early termination of franchise rights through equity transfer is the relatively superior approach, as it offers strong operability, does not affect normal operations, helps maintain workforce stability, imposes relatively low fiscal pressure on the government, and aligns with policy requirements. Finally, taking China's first urban rail transit PPP project that was terminated during the operation phase—the Fuzhou Metro Line 2 electromechanical equipment PPP project—as a typical case, the study provides a detailed account of the entire process of successfully repurchasing the equity held by private investors and terminating the franchise agreement in advance, with the aim of offering reference and guidance for equity repurchase and exit practices in urban rail transit PPP projects.

In the operation of ultra-large-scale urban rail transit networks, train operation delays occur frequently. Accurately and efficiently predicting the number and scope of affected passengers is crucial for network command and dispatch. Based on the normal passenger flow situation, this paper combines the advantages of data-driven and model-driven methods and proposes a short-term prediction method for the scope and number of affected passengers under urban rail train delays. First, based on the detailed OD path data of passenger travel chains under normal conditions, by analyzing the passenger flow direction in the delayed section, the scope of affected passengers is defined and a passenger flow quantity prediction model is constructed. Second, for the affected passenger group, according to the travel choice behavior of passengers under delay conditions, the passenger impedance sensitivity coefficient is calibrated to predict the structural changes of passenger components (waiting, detouring, and loss). Finally, multiple actual train delay scenarios in the Beijing urban rail network are selected for verification. The results show that this method can be effectively applied to multiple scenarios in the Beijing urban rail network. The average relative error of the prediction during the morning peak on weekdays is 4.8%. The time-consuming for predicting various passenger flow indicators within the next 30 minutes with a 5 minute granularity does not exceed 140 seconds, which shows good universality, accuracy, and timeliness. Currently, this solution has been successfully applied in the Beijing Rail Transit Command Center, providing passenger flow risk warnings, passenger guidance, and emergency coordination support for network dispatchers.

As urban rail transit networks continue to expand, junction areas in cross-line operations have increasingly become critical bottlenecks limiting capacity improvement. To alleviate passenger congestion during peak hours, this paper proposes a virtually coupled train coordination and scheduling method that incorporates passenger service level considerations. A train dynamics model is first established based on traction-braking characteristics and state transition rules. Then, a passenger- oriented Nash equilibrium game framework is constructed by introducing passenger priority levels to achieve coordinated optimization of train operation strategies. Furthermore, a bi-objective optimization function is formulated to balance two key indicators: passenger travel time and platform crowding. Finally, taking the junction area of Chongqing Rail Transit Lines 4, Loop Line, and Line 5 as the research object, eight typical operation scenarios are constructed to conduct simulation verification of the virtual coupling strategy, moving block strategy, and First Come First Serve (FCFS) strategy, and the impact of passenger flow changes on optimization effectiveness is analyzed. Simulation results demonstrate that, under peak operating conditions, the proposed method reduces passenger travel time cost by approximately 3% and platform congestion by around 30% compared to the traditional First Come First Serve (FCFS) strategy and the moving block-based game approach, significantly enhancing transportation efficiency and passenger satisfaction in cross-line operation zones.

In view of the growing demand for vehicle-ground integrated communication services and the limitation of frequency resources, this study investigates 5G network slicing technology for signal system business transmission under the vehicle-ground wireless communication architecture. First, the study analyzes the requirements of the current vehicle-ground integrated communication services and the status of the transmission system, and proposes the feasibility of using 5G network slicing technology to address these issues. Second, the system is designed from two aspects: network scheme and slicing scheme. Finally, taking the vehicle-ground business transmission of the signal system as an example, an experimental verification of the signal system business transmission at the 160 km/h speed was conducted on Guangzhou Metro Line 18. The results show that compared with the PRB reserved slice, the probability of the PRB reserved slice with a delay less than 150ms is 7.94% higher than that of the ordinary slice, reaching 99.87%, and the packet loss rate is 1.47% lower than that of the ordinary slice, reaching 0.08%; The percentage of PRB reservation+QoS slice delay less than 150ms has increased to 99.99%, while the packet loss rate has decreased to 0.5G network slice configuration PRB reservation and increasing QoS can meet the service transmission requirements of the signal system. The research results can provide reference for the transmission of signal system services in 5G networks at 160 km/h.

In order to effectively identify and prevent and control the safety hazards of ground settlement along the subway lines and surrounding areas, it is crucial to carry out systematic settlement monitoring. In this study, the spatial and temporal evolution characteristics of ground settlement in Urumqi metropolitan area, including cumulative settlement and settlement time series data, are obtained based on the small baseline set interferometry (SBAS-InSAR) technique. At the same time, the autoregressive integral sliding average (ARIMA) prediction model is combined to predict the deformation trend of the key subsidence areas, and an in-depth analysis is carried out for the typical subsidence sections along the subway line. The results of the study show that: Shayibak district, Shuimogou district, Urumqi county and the new urban area have obvious subsidence and subsidence funnel areas, and the annual subsidence in some areas reaches -31.4～-7.3 mm. the subway line 1 and 2 have obvious subsidence in some sections, and the area of subsidence area is large, which needs to be paid attention to the road section. The ARIMA model is used to predict the future 12-period data of the two settlement areas of D4 and D5 with high prediction accuracy, which can be used as a reference for later monitoring.

Based on the shield tunneling subway crossing through the existing anchor cable group between Wenfu Road Station and Fuming Street Station of Shenyang Subway Line 3 as the background. The paper analyzed various treatment schemes for shield tunneling through anchor cable areas. Through comprehensive comparison of technology, economy, and construction period, combined with the actual project conditions, a scheme was proposed involving the mining primary lining method to excavate tunnels, remove intruding anchor cables, backfill with mortar, and subsequently conduct shield tunneling. Numerical model analyses were performed for various construction stages, and comparative analyses were conducted by integrating on-site monitoring data. The results show that the mining primary lining method can effectively remove anchor cables, and mortar backfilling eliminates obstacles and hidden dangers for subsequent shield construction. The shield advancement proceeded normally without requiring chamber opening. The surface deformation data from construction monitoring is slightly larger than that from numerical analysis, but the deformation patterns are basically consistent, both showing a trend of larger values in the middle and smaller values towards the edges. Engineering practice has proven that the method is safe and reliable, and it can provide a reference for similar projects.

To reduce the operational cost of air-conditioning systems in subway stations, a cold storage air-conditioning system using phase change materials (PCMs) is proposed. The system can operate in four modes, namely, space cooling and cold charging by chillers, space cooling by chillers, space cooling by cold discharging, space cooling by chillers and cold discharging modes. The PCM used is a commercially available inorganic material, and its phase change temperature range is 7.5℃～8.5℃ and heat of fusion is 140 kJ/kg. The PCM is encapsulated in panel containers. A series of PCM slabs are parallelly arranged in the cold storage tank. The gap between the two adjacent PCM slabs serves as the flow channel for water, which exchanges heat with PCMs to store and release cold energy. The characteristics of chillers and cooling towers are modeled with the curve fitting method using the measured performance data. A dynamic computational model of the cold storage system which consists of a heat transfer numerical model of PCM slabs and the performance curves of chillers and cooling towers is built. The simulations are performed under the measured data in a subway station in Guangzhou. A control strategy is developed, then, the performance of the cold storage system is studied and compared to the conventional air-conditioning system. The variations of the melted fractions of PCMs, the inlet temperature, outlet temperature and water flow rate of cold storage tank, chillers and cooling towers, and the input power of system versus time on May 1st in 2023 are analyzed. In addition, a economic analysis of the proposed cold storage system is performed. The results show that, under the demand tariff, 8.27% annual operational cost is saved by the cold storage system over the conventional system, with a static payback period of 6.3 years. While 13.34% can be saved by the cold storage system against the conventional system under the discounted electricity tariff, with a static payback period of 3.7 years.

To address the difficulty of on-site verification for urban rail transit rail potential and stray current prevention measures, the rail potential hardware dynamic emulator system of rail potential has attracted widespread attention. Existing passive hardware emulator schemes usually achieve dynamic adjustment of the equivalent output resistance by modulating the average insertion time of a fixed power resistor. However, due to the heating and power limitations of fixed power resistors, it is difficult to increase the power rating. Therefore, this paper proposes an active rail potential hardware dynamic emulator (ARPHDE) system. Based on the analysis of the operating principle of the ARPHDE, a coordinated control strategy for the virtual resistance converter unit (VRCU), large resistance converter unit (LRCU), and section switching switches is developed, enabling precise regulation of the equivalent virtual resistance value. Simulation results demonstrate that the ARPHDE can accurately reproduce the spatiotemporal dynamic distribution patterns of rail potential. Compared to traditional passive hardware emulator schemes, the ARPHDE system replaces fixed power resistor regulation with virtual resistance regulation, avoiding issues of the fixed power resistor heating and showing promising application prospects.

In response to the problems of complex interaction, poor path planning, and untimely information display in traditional roaming methods in the three-dimensional scenarios of rail transit engineering, an adaptive roaming method is proposed to solve the pain points of three-dimensional scene visualization and engineering information display and communication. By integrating long-line, large-scale, and multi-source heterogeneous data generated during rail transit informatization, building information modeling (BIM) and geographic information system (GIS) data fusion technology is used to build high-precision three-dimensional scenarios. Automatically plan to generate the optimal roaming path based on line geometric features and interest point distribution; combined with key technologies such as camera attitude dynamic control, roaming interest point capture, and information synchronization display, smooth transition of perspective and real-time presentation of key information are achieved. The technology is applied to the information construction process of one national railway and five intercity railways in Shenzhen, forming a rail transit BIM+GIS roaming system, providing an efficient and interactive three-dimensional visualization solution for rail transit project management, application display and communication.

The signaling system renovation project of Jinbin Light Rail Line 9 is facing strong constraints such as the type of of the terminal station for pre-station turnback, insufficient length of the train inspection garage line, and tight equipment room area. There are significant contradictions with the renovation goals of achieving a 2-minute turnback interval, upgrading the function of the automated train inspection garage, and installing equipment without disturbance. Targeted optimization design is needed. Firstly, the current research status of signaling system transformation was introduced, and the constraints of strong constraint conditions on design objectives were analyzed. Secondly, the focus of the design research is on three aspects: pre-station turnback capability, automated train inspection garage design, and signaling room equipment layout. The key bottlenecks that conventional design methods cannot meet the renovation goals under strong constraints are identified. Finally, this paper proposes a systematic optimization plan: adding axle counter equipment in the pre-station crossover section and changing the switch control logic from double-acting to single-acting, optimizing the safety braking model for train inspection garage stopping and adjusting the C-track interlocking logic, and adopting an uninterruptible power supply (UPS)/battery transition scheme for centralized stations while streamlining the equipment configuration at non-centralized stations. The application results show that the optimization measures effectively solve the contradiction between strong constraints and renovation goals. The turnback interval of the pre-station has been compressed from 136 seconds to within 120 seconds, meeting the requirement of 2-minute operation; The protection distance required for automatic stopping of trains has been shortened from 7.56 meters to within 3.8 meters, achieving automatic entry and exit of trains into the inspection garage; At the same time, the space requirements for equipment installation were reduced, and the equipment was installed without disturbance under the existing equipment room conditions.

This paper aims to effectively integrate knowledge from metro construction quality acceptance standards and address the current issues of singular knowledge organization methods, as well as isolated and fragmented knowledge. Based on the collection of metro construction quality acceptance standards issued by national and representative municipal authorities, generative AI was employed to extract key knowledge elements. A knowledge graph was then constructed using graph database software, and a multidimensional knowledge retrieval method along with node importance evaluation were proposed. Taking the construction of metro open-cut stations as an example, the proposed methods were applied to conduct an in-depth analysis of key knowledge at various stages of quality acceptance for this unit project, and acceptance recommendations were provided. [Conclusion] The knowledge graph of metro construction quality acceptance standards can offer comprehensive knowledge support for quality acceptance, providing significant reference value for improving the knowledge management level and utilization capability of metro construction quality acceptance standards.

Aiming at the common issues of insufficient scene adaptability and inadequate modeling of temporal feature dependencies in existing visual fatigue detection methods, this paper proposes an intelligent rail driver fatigue detection algorithm based on facial multi-features and Bi-LSTM. First, the algorithm uses Dlib to locate the driver's facial keypoints and calculates five fatigue feature parameters, including the Eye Aspect Ratio (EAR), Mouth Aspect Ratio (MAR), and head pose angles. It also proposes the frequency of longitudinal head scanning behavior for distraction detection. Second, the Bi-LSTM network is employed to establish temporal dependencies and complete the determination of the driving state. Third, temporal attention is introduced to enhance the representation capability of key features, improving the overall performance of the algorithm. Finally, the research results show that, compared to traditional models, the proposed method achieves an accuracy of 94.24% and improves the F1-Score from 0.8324 to 0.9027, validating the effectiveness and feasibility of the proposed approach. The findings can provide a reference for public transportation safety assurance.

In response to seismic events that render certain metro sections impassable or subject to speed restrictions, this study proposes an optimization model for metro train emergency rescheduling based on Earthquake Early Warning (EEW) information. The model proactively adjusts existing train operation plans before the earthquake occurs, upon receiving EEW alerts. It incorporates constraints such as arrival and departure time constraints, headway constraints, rolling stock circulation constraints, and earthquake impact-related constraints. The objective function aims to minimize the deviation between actual and ideal train headways, the number of skipped station stops, and the time trains operate within hazardous zones after the earthquake. A linearization method is used to convert the model into a Mixed-Integer Linear Programming (MILP) formulation. To verify the effectiveness of the proposed model under various earthquake scenarios, a case study is conducted using actual operational data from Line 6 of the Kunming Metro on a typical working day. The results show that the model can generate emergency train rescheduling plans based on EEW information under different earthquake intensities and affected areas. Different rescheduling strategies are adopted depending on the location of the train at the time of receiving the EEW alert. When speed restrictions are imposed due to the earthquake, a greater increase in inter-station running time leads to a more significant impact on train operations.

To address the need for efficient transportation of high-value-added and time-sensitive goods and resolve the challenge of selecting optimal freight paths within the complex urban rail transit networks of megacities, this study presents a comprehensive approach. First, a network simplification method is proposed to streamline the topological structure of urban rail systems by accounting for network complexity and uneven passenger flow distribution, thereby enhancing the computational efficiency of multimodal path optimization algorithms. Second, a path optimization model is developed with dual objectives of maximizing load rate and minimizing operational costs to balance cargo capacity utilization and economic feasibility. Finally, a hybrid algorithm integrating an improved ant colony optimization and particle swarm optimization is designed to solve the model, where particle swarm optimization optimizes the hyperparameters of the ant colony algorithm to accelerate convergence speed. Validated through a case study in Guangzhou, the methodology achieves significant performance improvements: network simplification reduces nodes by 76% and links by 69%, cutting algorithm runtime from 11,849 seconds to 1,613 seconds and boosting computational efficiency by 87.4%. The hybrid algorithm further reduces iterations from 46 to 15 while maintaining solution quality. Comparative analysis confirms the superiority of this approach in balancing computational speed, resource utilization, and path optimization effectiveness for urban rail freight systems.

To the lack of technologies and practical experience in non-suspension renovation of underground station platforms under non-reserved conditions in China, a study is conducted on the civil engineering renovation situation and the platform renovation practices of Tokyo Metro underground stations. Firstly, through statistics, the spatiotemporal distribution characteristics of Tokyo Metro stations that have undergone civil engineering renovation are analyzed, and the influence of laying method and reserved conditions on the timing and construction duration of renovation is explored. Subsequently, the process for civil engineering renovation of Tokyo Metro underground stations is delineated. Finally, based on specific cases, the main objectives and key points of platform extension, platform widening, platform addition and comprehensive platform renovation are analyzed, and relevant insights for the construction of metro stations in China are summarized. The study results show that about 15.1% of the current 259 underground stations of Tokyo Metro have undergone civil engineering renovation, which is a considerable number. The civil engineering renovation construction steps of underground stations usually follow “from outside to inside, build new first and then demolish old”. For the underground stations of Tokyo Metro, only platform extension may have reserved platform extension space based on the length of future train formation, whereas platform renovations under non-reserved conditions prioritize minimizing renovation scale, demonstrating that underground lines need to pay attention to reservation design with high cost-effectiveness and the underground station platform renovation under no reserved conditions needs to emphasize targeting. The long-term station renovation project needs to strengthen risk warning and dynamic control. Station-city integration requires balancing station passenger flow carrying capacity with surrounding land development intensity. The study findings can provide reference for the design and renovation of underground station platforms in China.