Search Results (42)

Traditional multi-modal dynamic transit assignment (DTA) models predominantly focus on bus and rail systems, overlooking the role of bike-sharing in passenger flow distribution. To bridge this gap, a multi-modal dynamic transit assignment model incorporating bike-sharing (MMDTA-BS) is proposed. This model integrates bike-sharing, buses, rail services, and walking into a unified framework. Represented by the variational inequality (VI), the MMDTA-BS model is proven to satisfy the multi-modal dynamic transit user equilibrium conditions. To solve the VI formulation, a projection-based approach with dynamic path costing (PA-DPC) is developed. This approach dynamically updates path costs to accelerate convergence. Experiments conducted on real-world networks demonstrate that the PA-DPC approach achieves rapid convergence and outperforms all compared algorithms. The results also reveal that bike-sharing can serve as an effective means for transferring passengers to rail modes and attracting short-haul passengers. Moreover, the model can quantify bike-sharing demand imbalances and offer actionable insights for optimizing bike deployment and urban transit planning. Full article

While prior studies on LULC change in the Ewa region of O’ahu Hawai’i have explored the policy implications and the rapid infrastructure changes on land use, very few studies have attempted to fully integrate both of these changes in a comprehensive, long-term study of island geographies. Most of the past work has focused on general trends or short-term fluctuations, without considering the play of nuanced interactions between urbanization policies, transit-oriented development, and constraints of Hawai’i’s finite land resources. To fill these gaps, this study examines LULC changes in Ewa, Honolulu between 2002 and 2022, which emphasizes the impacts of strategic urban policies and infrastructure development, such as the Honolulu Skyline Rail Transit System. Using Landsat 7 satellite imagery and random forest machine learning classifier, in Google Earth Engine, LULC is classified into urban, forest, vegetation, barren, and water with classification accuracy of over 85%. The results highlight trends of significant urban growth especially after 2010, and highlight key issues of tension between housing demands and environmental sustainability in O’ahu. This study highlights the potential of integrated remote sensing and policy analysis for informing sustainable development in land-constrained island settings, and advocates for planning frameworks that more effectively balance growth, ecosystem stewardship, and community welfare. Full article

With the continuous expansion of urban rail transit networks, construction safety of connecting passages—as critical weak links in underground structural systems—has become pivotal for project success. Although artificial ground freezing technology effectively addresses adverse geological conditions (e.g., high permeability and weak self-stability), it is influenced by multi-field coupling effects (temperature, stress, and seepage fields), which may trigger chain risks such as freezing pipe fractures and frozen curtain leakage during construction. This study deconstructed the freezing method workflow (‘drilling pipe-laying → active freezing → channel excavation → structural support’) and established a hierarchical evaluation index system incorporating geological characteristics, technological parameters, and environmental impacts by considering sandy soil phase-change features and hydro-thermal coupling effects. For weight calculation, the Analytic Hierarchy Process (AHP) was innovatively applied to balance subjective-objective assignment deviations, revealing that the excavation support stage (weight: 52.94%) and thawing-grouting stage (31.48%) most significantly influenced overall risk. Subsequently, a Bayesian network-based risk assessment model was constructed, with prior probabilities updated in real-time using construction monitoring data. Results indicated an overall construction risk probability of 46.3%, with the excavation stage exhibiting the highest sensitivity index (3.97%), identifying it as the core risk control link. These findings provide a quantitative basis for dynamically identifying construction risks and optimizing mitigation measures, offering substantial practical value for enhancing safety in subway connecting passage construction within water-rich sandy strata. Full article

We introduce a novel optimization method, the Bud Lifecycle Algorithm (BLA), and present a mathematical model for optimizing urban transportation systems, demonstrated through a Baltimore case study. Our approach centers on the Proximity Topology Attribute Model, which integrates topological graph properties with K-means clustering to partition city nodes and identify key activity areas via betweenness centrality. A simulated bridge collapse reveals significant impacts on insurance companies and transport users. To balance traffic efficiency with construction costs in public transport projects, we propose a multi-objective optimization model prioritizing transit hubs while minimizing expenses in congested zones. We introduce the Bud Lifecycle Algorithm (BLA) to enhance traditional Genetic Algorithm performance, achieving improvements in system coverage, cost-efficiency, and user satisfaction. Our findings suggest that expanding public transport networks and optimizing rail projects could substantially boost employment and tourism in West Baltimore. We propose the Smart Traffic Management System (STMS) and Community Traffic Safety Program (CTSP) to enhance traffic safety, reduce congestion, and improve residents’ quality of life. Full article

Land Value Capture (LVC) is increasingly being emphasized as a key mechanism for financing mass transit systems, promoted as a sustainability-oriented policy tool amid tightening public budgets. China has adopted a development-led approach to value capture through the “Rail plus Property (R + P)” model, drawing inspiration from the Hong Kong experience. The Shenzhen Metro’s “R + P” strategy has been widely acclaimed as the key to its reputation as “the only profitable transit company in mainland China without subsidies.” This paper questions this assumption and argues that the Shenzhen model is neither sustainable nor replicable, as its past performance depended on two exceptional conditions: an ascending phase of a real-estate cycle and unique institutional concessions from the central state. To substantiate this argument, we contrast Shenzhen’s value capture strategy with that of Nanjing—a provincial capital operating under routine institutional conditions, with governance and spatial structures broadly reflecting the prevailing urban development model in China. Using a comparative framework structured around three key dimensions of LVC—urban governance, risk management, and the transit company’s shift toward real estate—this paper reveals how distinct urban political economies give rise to contrasting value capture approaches: one expansionary, prioritizing short-term profit and rapid scale-up while downplaying risk management (Shenzhen); the other conservative, shaped by institutional constraints and characterized by reactive, incremental adjustments (Nanjing). These findings suggest that while LVC instruments offer valuable potential as a funding source for public transit, their long-term viability depends on early institutional embedding that aligns spatial, fiscal, and political interests, alongside well-developed project planning and capacity support in real estate expertise. Full article

The prediction of ground deformation during ultra-shallow-buried pilot tunnel construction is critical for urban rail transit projects in complex geological settings, yet existing cross-section models often lack accuracy. This study proposes an enhanced non-uniform convergence model based on stochastic medium theory, which decomposes surface settlement into uniform soil shrinkage and non-uniform initial support deformation. A computational formula for horseshoe-shaped sections is derived and validated through field data from Kunming Rail Transit Phase I, demonstrating a 59% improvement in maximum settlement prediction accuracy (reducing error from 7.5 mm to 3.1 mm) compared to traditional methods. Its application to Beijing Metro Line 13 reveals two distinct deformation patterns: significant ground heave occurs at 2.5 times the tunnel width from the centerline, while maximum settlement concentrates above the excavation center and diminishes radially. To mitigate heave, early strengthening of the secondary lining is recommended to control initial horizontal deformation. These findings enhance prediction reliability and provide actionable insights for deformation control in similar urban tunneling projects, particularly under ultra-shallow burial conditions. Full article

With the acceleration of urbanization, the development of urban rail transit networks has become an essential component of modern urban transportation. The construction of new urban rail transit lines often involves crossing existing operational lines, posing significant safety risks and technical challenges. This paper presents a comprehensive study on the safety risk assessment and control measures for the construction of new double-line shield tunnels crossing beneath existing tunnels in complex strata, using the project of Line 5 of the Nanning Urban Rail Transit crossing beneath the existing Line 2 interval tunnel as a case study. This study employs methods such as status investigation, numerical simulation, and field measurement to analyze the construction risks. Key findings include the successful identification and control of major risk sources through refined risk assessment and comprehensive technical measurement. The maximum settlement of the existing tunnel was effectively controlled at −2.55 mm, well within the deformation monitoring control values. This study demonstrates that optimized shield machine selection, improved lining design, interlayer soil reinforcement, the dynamic adjustment of shield parameters, and the precise measurement of shield posture significantly enhance the efficiency of shield tunneling and construction safety. The results provide a valuable reference for the settlement and deformation control of similar projects. Full article

With the growing demand for mobility fueled by global population expansion and rapid urbanization, the intricate interplay between public transport and land use, along with their economic, environmental, and social externalities, has emerged as a critical concern for policymakers and the public alike. This study assembles publicly available academic literature, including papers, reports, books, and news articles, to construct a comprehensive database. Using CiteSpace 5.8.R3 software, this study conducts a visualized analysis of 10,470 scholarly works on public transport and land use published since 1932, identifying and synthesizing the researcher, research stages, research theories, research models, and research hotspots. Findings reveal that since Mitchell and Rapkin first introduced the transport–land use relationship in 1954, research in this field has steadily gained traction, particularly after the 1973 oil embargo crisis. The Journal of Transport and Land Use and institutions such as the University of Minnesota’s Transportation Research Center have played pivotal roles, particularly with the establishment of the World Society for Transport and Land Use Research (WSTLUR). In recent years, China’s high-speed rail expansion has further revitalized interest in this field. Prominent scholars in this domain include Robert Cervero, Reid Ewing, Michael Duncan, and Peter Calthorpe. Major theoretical frameworks encompass utility theory, urban economic theory, and the human–land system theory. Key modeling approaches include the spatial interaction model, the stochastic utility model, and urban economic models. Current research hotspots center on safety and public health, equity and valuation, environmental sustainability and energy efficiency, as well as transit-oriented development (TOD) and accessibility. This systematic literature review offers valuable insights to inform land use planning, enhance spatial structure, guide transportation project decision making, and optimize transport infrastructure and service provision. Full article

This study investigates the role of subcontracting partnerships in enhancing collaboration and sustainability in urban rail transit system design, addressing the challenges posed by fragmented practices and environmental goals under China’s “Dual Carbon” policy. Using a mixed-methods approach, we integrate structural equation modeling (SEM) and factor analysis to identify critical success factors (CSFs) and their impacts on design performance. SEM, a statistical technique capable of analyzing complex relationships between unobservable “latent variables” (e.g., trust, innovation) and measurable outcomes, was employed to validate the hypothesized relationships among five key factors: Excellence in Quality, Interactive Collaboration, Collaborative Vision, Risk Strategy, and Strategic Innovation. Factor analysis consolidated 19 CSFs from the literature into these five constructs, explaining 69.09% of the variance. The SEM results revealed that Excellence in Quality, Interactive Collaboration, Risk Strategy, and Strategic Innovation directly improve design performance, while Collaborative Vision indirectly influences outcomes through mediating effects on risk management and innovation. These findings provide actionable strategies for leveraging BIM/blockchain tools and institutional frameworks to enhance sustainability in urban transportation projects. By contextualizing partnership dynamics within China’s state-led infrastructure ecosystem, this research enriches the theoretical understanding of partnership mechanisms. Full article

China’s urban rail transportation sector has been developing rapidly in recent years. However, frequent construction activities have led to more construction safety accidents, resulting in life and economic losses. To deal with safety accidents, emergency preparedness documents are fully developed. Based on the theory of ontology, this study proposed a case-based reasoning method that can retrieve the most similar cases to the target case and help to develop emergency preparedness documents quickly and efficiently. Specifically, an ontological framework for urban rail construction safety was constructed first in the Protégé platform based on risk factors of urban rail construction projects. Then, a case retrieval method was proposed, calculating the similarities between source cases and target cases. The analytic hierarchy process was used to determine the weights of each risk factor to match the most similar cases and provide a reference for the rapid generation of emergency preparedness of target cases. This study contributes to the current body of knowledge by providing valuable examples for the application of ontology-based case-based reasoning technology in the field of hazard management, which not only realizes knowledge sharing and full and effective utilization of past experiences but also significantly improves the hazard prevention and emergency preparedness capabilities in urban rail transit construction projects. At the same time, this study makes hazard management more systematic and efficient and provides important support for the long-term sustainable development of the urban rail transit construction industry in both social and economic dimensions. Full article

This study investigates the viability of incorporating bicycles into the Dhaka Metro system, a groundbreaking urban transit project for Bangladesh. As Dhaka’s inaugural metro rail network, the system signifies a substantial advancement in addressing urban congestion and enhancing transportation alternatives in one of the world’s most densely populated cities. The current design of the metro fails to accommodate bicycles, hindering efficient first- and last-mile connectivity. The investigation utilized data from 382 fully completed questionnaires, obtained through purposive sampling, about metro–cycle integration in Dhaka. The research employed RIDIT and TOPSIS analyses to rank the characteristics deemed most essential for bicycle–metro integration according to user opinions. Research indicates that secure bicycle parking, multi-modal ticketing, route comfort, and safety measures are the foremost objectives for commuters. The high emphasis on secure parking indicates the need for safe and accessible storage options that would make cycling a viable mode for reaching metro stations. A multi-modal ticketing system further enhances convenience, providing seamless transitions between transit modes. Journey comfort and the need to mitigate risks posed by motorized vehicles underscore the importance of safe and user-friendly commuting environments. While features like road and station design were ranked lower in priority, the study emphasizes that a well-integrated bicycle infrastructure is essential to ensure the metro system’s success. With these improvements, Dhaka’s metro system can meet the growing demands for sustainable and inclusive urban mobility, setting a precedent for future infrastructure projects in Bangladesh. Full article

Urban rail transit is one of the vital lifeline projects of megacities worldwide. While it brings convenience and economic growth to the city, the construction of urban rail transit projects is often associated with safety accidents. Emergency preparedness plays a significant role in the prevention of safety accidents and emergency rescue in urban rail transit construction projects. However, the extant literature rarely looks into this topic. The aims of this study are to review the emergency preparedness of current urban rail transit construction projects in China, to summarize their key elements, to identify their advantages and limitations, and to make recommendations accordingly. To achieve these goals, this study systematically investigates the emergency preparedness documents implemented by 52 cities in mainland China; from these, five key elements of emergency preparedness are systematically reviewed: organization; monitoring and early warning; emergency response; post-disaster recovery and reconstruction; emergency support. The advantages and limitations of existing emergency preparedness are examined, and recommendations for updates to emergency preparedness are made based on the experience and knowledge of advanced economies. The findings of the study can enhance understanding among authorities and industry practitioners of emergency preparedness as it is implemented in current urban rail construction projects. It can also provide a practical reference for the improvement of emergency preparedness of urban rail transit construction projects in the future, thereby contributing to the resilience and long-term sustainability of urban rail transit systems. Full article

Soft marine soil exhibits unique mechanical properties that can lead to significant deformation and instability in the surrounding rock of urban subway tunnels. This presents a critical challenge for tunnel engineering researchers and designers. This thesis investigates the stability characteristics of surrounding rock in marine soft soil tunnels under cyclic loading conditions. Focusing on the shield tunnel segment between Left Fortress Station and Taiziwan Station of Shenzhen Urban Rail Transit Line 12, a discrete–continuous coupled numerical analysis method is employed to examine the deformation characteristics of the surrounding rock. This analysis takes into account the effects of dynamic loads resulting from train operations on the arch bottom’s surrounding rock. The findings indicate that damage to the surrounding rock occurs gradually, with the marine soft soil layer, particularly at higher water content, being prone to substantial plastic deformation. Additionally, under the influence of train vibration loads, the degree of vertical fluctuation in the internal marine soft soil diminishes with increasing depth from the bottom of the tunnel arch. This coupled numerical analysis approach offers valuable insights and methodologies for assessing the structural safety of tunnel projects throughout their operational periods. Full article

With the rapid development of urban rail transit networks, constructing shield tunnels often requires passing underneath existing buildings, which can potentially impact their safety. This study examined the impact of constructing a double-line shield tunnel underneath a railway bridge on the adjacent pile foundation via numerical simulation. Protective measures, including construction parameter control, grouting methods, monitoring, and early warning systems, were implemented to mitigate impacts. The results indicated that the bridge deformation fell within acceptable limits, with maximum horizontal and longitudinal displacements of 0.06 mm and a maximum vertical displacement of −0.31 mm. The railway bridge pile foundation experienced maximum horizontal and longitudinal displacements of 0.47 mm and vertical displacements of −0.23 mm during construction. Enhanced construction quality control and monitoring effectively controlled deformation to ensure the railway safety. This study provides valuable guidance for similar projects and future urban rail transit developments. Full article

With the advancement of China’s construction industry and the rapid pace of urbanization, there has been heightened concern about and demand for improved construction environments. Rail transit projects commonly experience noise levels that exceed standard limits, resulting in a significant challenge posed by construction noise pollution. This issue not only disrupts the normal operations of construction sites but also profoundly impacts the mental well-being, auditory health, and nervous system of both construction workers and nearby residents. Consequently, effectively addressing construction noise pollution has emerged as a pressing issue. This study systematically reviewed domestic and international construction noise standards, integrating field research and noise monitoring data from construction sites. It provided a detailed analysis of the sources and hazards of construction noise and explored the source and propagation characteristics of construction noise from rail transit projects. The feasibility of controlling construction noise from various perspectives was investigated. Finally, the study analyzed the causes of construction noise exceeding standard limits, proposed layout strategies and control methods tailored to the stages of construction, and offered comprehensive noise control recommendations, culminating in a complete control process. This study fills a gap in research related to construction noise for rail transit projects, provides a valuable foundation for developing construction noise control objectives, and offers practical guidance on the implementation of measurement and control methods. These insights will help advance the field of construction noise control and management, and provide valuable insights for similar domestic rail transit projects. Full article