1,048 research outputs found

    Doctor of Philosophy

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    dissertationData-driven analytics has been successfully utilized in many experience-oriented areas, such as education, business, and medicine. With the profusion of traffic-related data from Internet of Things and development of data mining techniques, data-driven analytics is becoming increasingly popular in the transportation industry. The objective of this research is to explore the application of data-driven analytics in transportation research to improve the traffic management and operations. Three problems in the respective areas of transportation planning, traffic operation, and maintenance management have been addressed in this research, including exploring the impact of dynamic ridesharing system in a multimodal network, quantifying non-recurrent congestion impact on freeway corridors, and developing infrastructure sampling method for efficient maintenance activities. First, the impact of dynamic ridesharing in a multimodal network is studied with agent-based modeling. The competing mechanism between dynamic ridesharing system and public transit is analyzed. The model simulates the interaction between travelers and the environment and emulates travelers' decision making process with the presence of competing modes. The model is applicable to networks with varying demographics. Second, a systematic approach is proposed to quantify Incident-Induced Delay on freeway corridors. There are two particular highlights in the study of non-recurrent congestion quantification: secondary incident identification and K-Nearest Neighbor pattern matching. The proposed methodology is easily transferable to any traffic operation system that has access to sensor data at a corridor level. Lastly, a high-dimensional clustering-based stratified sampling method is developed for infrastructure sampling. The stratification process consists of two components: current condition estimation and high-dimensional cluster analysis. High-dimensional cluster analysis employs Locality-Sensitive Hashing algorithm and spectral sampling. The proposed method is a potentially useful tool for agencies to effectively conduct infrastructure inspection and can be easily adopted for choosing samples containing multiple features. These three examples showcase the application of data-driven analytics in transportation research, which can potentially transform the traffic management mindset into a model of data-driven, sensing, and smart urban systems. The analytic

    2021 International Symposium on Transportation Data and Modelling

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    This project partially sponsored the organization of the 2021 International Symposium on Transportation Data and Modeling(ISTDM 2021), which aims to gather transportation researchers and practitioners across the globe for exploring the frontiers of bigdata, modeling and simulation to advance transportation research to support the connected, cooperative and automated mobility.Due to the COVID-19 pandemic, the conference was held virtually June 21-24, 2021. Its program consisted of 8 keynote talks, and104 regular or lightning talks. It attracted more than 1,100 registrations, and the accumulated number of attendees was more than2960.U.S. Department of Transportation Office of the Assistant Secretary for Research and Technology 1200 New Jersey Avenue, SE Washington, DC 20590http://deepblue.lib.umich.edu/bitstream/2027.42/168542/1/2021_08_06 - 2021 International Symposium on Transportation Data and Modelling Final Report.pdfDescription of 2021_08_06 - 2021 International Symposium on Transportation Data and Modelling Final Report.pdf : Final ReportSEL

    e-Sanctuary: open multi-physics framework for modelling wildfire urban evacuation

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    The number of evacuees worldwide during wildfire keep rising, year after year. Fire evacuations at the wildland-urban interfaces (WUI) pose a serious challenge to fire and emergency services and are a global issue affecting thousands of communities around the world. But to date, there is a lack of comprehensive tools able to inform, train or aid the evacuation response and the decision making in case of wildfire. The present work describes a novel framework for modelling wildfire urban evacuations. The framework is based on multi-physics simulations that can quantify the evacuation performance. The work argues that an integrated approached requires considering and integrating all three important components of WUI evacuation, namely: fire spread, pedestrian movement, and traffic movement. The report includes a systematic review of each model component, and the key features needed for the integration into a comprehensive toolkit

    Human mobility: Models and applications

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordRecent years have witnessed an explosion of extensive geolocated datasets related to human movement, enabling scientists to quantitatively study individual and collective mobility patterns, and to generate models that can capture and reproduce the spatiotemporal structures and regularities in human trajectories. The study of human mobility is especially important for applications such as estimating migratory flows, traffic forecasting, urban planning, and epidemic modeling. In this survey, we review the approaches developed to reproduce various mobility patterns, with the main focus on recent developments. This review can be used both as an introduction to the fundamental modeling principles of human mobility, and as a collection of technical methods applicable to specific mobility-related problems. The review organizes the subject by differentiating between individual and population mobility and also between short-range and long-range mobility. Throughout the text the description of the theory is intertwined with real-world applications.US Army Research Offic

    Flood Impacts on Road Transportation

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    Flood disasters can penetrate every single aspect of human life and road transportation is no exception. However, flood impacts on road transportation is an area that has not been explored in detail in the past. The focus of this PhD study is on the performance assessment of a road network subject to flooding. In this work, several challenges were overcome with original ideas. The first was integrating the flood and the transport systems - both exhibiting strong temporal and spatial variations. This has been successfully achieved by implementing a novel methodology into a tool that modelled flood intensities output into a transport network constraint in a traffic model. The logic of the framework is intuitive – roads with shallow flood depth impose speed limitations, and roads with deep flood depth are closed for traffic. The developed tool enabled a quick and consistent technique to integrate the flood and the transport models in three different ways – static, semi-dynamic and dynamic. The static integration considers only one flood map to determine traffic conditions, whereas the semi-dynamic and the dynamic integrations use multiple maps to mimic the flood propagation in the traffic model. This thesis is the first to achieve semi-dynamic or dynamic integration of the two models. The second challenge was the assessment of the impacts. Intangible impacts such as travel delays propagating as knock-on effects can easily be misrepresented or even misunderstood. Employing a microscopic transport model allows for the assessment of direct effects and the knock-on consequences on individual drivers as well as the whole traffic system. Results in one case study suggest that the average travel time rose with 45% on average for 75% of the vehicles in the most affected hour of the simulation. The monetary value of traffic delays may not be as significant as the flood direct tangible damage, but flood impacts on road transportation may be more straightforward to alleviate if traffic authorities follow contingency plans to reduce traffic demand or mitigate potential interruptions of traffic supply. To analyse how potential interventions affect the transport system performance, three interventions were implemented into the model. The third challenge was the evaluation of the performance of a road transport system and the assessment of its resilience to flooding. Perusing this, a novel rationale to assess the resilience of a transport network has been developed. This method distinguishes reliability from resilience to define the nonlinear bounds of standard dry weather conditions, and any fluctuation beyond these bounds is defined as exceptional conditions. By separating reliability from resilience, the extent of both magnitude and duration is refined and contributes to better understanding of the system performance. This PhD thesis aspires to bridge the gap between flooding and traffic by providing a workable open source tool, which can be applied to other case studies and thus open the potential for further development in that area. As well as practical ideas, the theoretical contribution in assessing system resilience can be applied in other fields.European Commissio

    Supporting Cross-sectoral Infrastructure Investment Planning

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    Human mobility:Models and applications

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    Recent years have witnessed an explosion of extensive geolocated datasets related to human movement, enabling scientists to quantitatively study individual and collective mobility patterns, and to generate models that can capture and reproduce the spatiotemporal structures and regularities in human trajectories. The study of human mobility is especially important for applications such as estimating migratory flows, traffic forecasting, urban planning, and epidemic modeling. In this survey, we review the approaches developed to reproduce various mobility patterns, with the main focus on recent developments. This review can be used both as an introduction to the fundamental modeling principles of human mobility, and as a collection of technical methods applicable to specific mobility-related problems. The review organizes the subject by differentiating between individual and population mobility and also between short-range and long-range mobility. Throughout the text the description of the theory is intertwined with real-world applications.Comment: 126 pages, 45+ figure
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