Download or read book Modeling Travel Time Uncertainty in Traffic Networks written by Daizhuo Chen and published by . This book was released on 2010 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainty in travel time is one of the key factors that could allow us to understand and manage congestion in transportation networks. Models that incorporate uncertainty in travel time need to specify two mechanisms: the mechanism through which travel time uncertainty is generated and the mechanism through which travel time uncertainty influences users' behavior. Existing traffic equilibrium models are not sufficient in capturing these two mechanisms in an integrated way. This thesis proposes a new stochastic traffic equilibrium model that incorporates travel time uncertainty in an integrated manner. We focus on how uncertainty in travel time induces uncertainty in the traffic flow and vice versa. Travelers independently make probabilistic path choice decisions, inducing stochastic traffic flows in the network, which in turn result in uncertain travel times. Our model, based on the distribution of the travel time, uses the mean-variance approach in order to evaluate travelers' travel times and subsequently induce a stochastic traffic equilibrium flow pattern. In this thesis, we also examine when the new model we present has a solution as well as when the solution is unique. We discuss algorithms for solving this new model, and compare the model with existing traffic equilibrium models in the literature. We find that existing models tend to overestimate traffic flows on links with high travel time variance-to-mean ratios. To benchmark the various traffic network equilibrium models in the literature relative to the model we introduce, we investigate the total system cost, namely the total travel time in the network, for all these models. We prove three bounds that allow us to compare the system cost for the new model relative to existing models. We discuss the tightness of these bounds but also test them through numerical experimentation on test networks.
Download or read book Applied Research in Uncertainty Modeling and Analysis written by Bilal M. Ayyub and published by Springer Science & Business Media. This book was released on 2007-12-29 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application areas of uncertainty are numerous and diverse, including all fields of engineering, computer science, systems control and finance. Determining appropriate ways and methods of dealing with uncertainty has been a constant challenge. The theme for this book is better understanding and the application of uncertainty theories. This book, with invited chapters, deals with the uncertainty phenomena in diverse fields. The book is an outgrowth of the Fourth International Symposium on Uncertainty Modeling and Analysis (ISUMA), which was held at the center of Adult Education, College Park, Maryland, in September 2003. All of the chapters have been carefully edited, following a review process in which the editorial committee scrutinized each chapter. The contents of the book are reported in twenty-three chapters, covering more than . . ... pages. This book is divided into six main sections. Part I (Chapters 1-4) presents the philosophical and theoretical foundation of uncertainty, new computational directions in neural networks, and some theoretical foundation of fuzzy systems. Part I1 (Chapters 5-8) reports on biomedical and chemical engineering applications. The sections looks at noise reduction techniques using hidden Markov models, evaluation of biomedical signals using neural networks, and changes in medical image detection using Markov Random Field and Mean Field theory. One of the chapters reports on optimization in chemical engineering processes.
Download or read book Traffic and Granular Flow 22 written by K. Ramachandra Rao (Associate professor in civil engineering) and published by Springer Nature. This book was released on 2024 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers contributions on a variety of flowing collective systems. While primarily focusing on pedestrian dynamics, it also reflects the latest developments in areas such as vehicular traffic and granular flows and addresses related emerging topics such as self-propelled particles, data transport, swarm behaviour, intercellular transport, and individual interactions to complex systems. Combining fundamental research and practical applications in the various fields discussed, the book offers a valuable asset for researchers and professionals in areas such as civil and transportation engineering, mechanical engineering, electrical engineering, physics, computer science, and mathematics.
Download or read book Network Reliability in Practice written by David Levinson and published by Springer Science & Business Media. This book was released on 2011-10-26 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains selected peer-reviewed papers that were presented at the Fourth International Symposium on Transportation Network Reliability (INSTR) Conference held at the University of Minnesota July 22-23, 2010. International scholars, from a variety of disciplines--engineering, economics, geography, planning and transportation—offer varying perspectives on modeling and analysis of the reliability of transportation networks in order to illustrate both vulnerability to day-to-day and unpredictability variability and risk in travel, and demonstrates strategies for addressing those issues. The scope of the chapters includes all aspects of analysis and design to improve network reliability, specifically user perception of unreliability of public transport, public policy and reliability of travel times, the valuation and economics of reliability, network reliability modeling and estimation, travel behavior and vehicle routing under uncertainty, and risk evaluation and management for transportation networks. The book combines new methodologies and state of the art practice to model and address questions of network unreliability, making it of interest to both academics in transportation and engineering as well as policy-makers and practitioners.
Download or read book The Evolution of Travel Time Information Systems written by Margarita Martínez-Díaz and published by Springer Nature. This book was released on 2022-01-21 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the estimation of travel time in a very comprehensive and exhaustive way. Travel time information is and will continue to be one key indicator of the quality of service of a road network and a highly valued knowledge for drivers. Moreover, travel times are key inputs for comprehensive traffic management systems. All the above-mentioned aspects are covered in this book. The first chapters expound on the different types of travel time information that traffic management centers work with, their estimation, their utility and their dissemination. They also remark those aspects in which this information should be improved, especially considering future cooperative driving environments.Next, the book introduces and validates two new methodologies designed to improve current travel time information systems, which additionally have a high degree of applicability: since they use data from widely disseminated sources, they could be immediately implemented by many administrations without the need for large investments. Finally, travel times are addressed in the context of dynamic traffic management systems. The evolution of these systems in parallel with technological and communication advancements is thoroughly discussed. Special attention is paid to data analytics and models, including data-driven approaches, aimed at understanding and predicting travel patterns in urban scenarios. Additionally, the role of dynamic origin-to-destination matrices in these schemes is analyzed in detail.
Download or read book Travel Time Prediction in the Prescence of Traffic Incidents written by Yang Tao and published by . This book was released on 2005 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Uncertainty in Large scale Urban Traffic Networks written by Xueyu Gao and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent work has proposed using aggregate relationships between urban traffic variables--i.e., Macroscopic Fundamental Diagrams (MFDs)--to describe aggregate traffic dynamics in urban networks. This approach is particularly useful to unveil and explore the effects of various network-wide control strategies. The majority of modeling work using MFDs hinges upon the existence of well-defined MFDs without consideration of uncertain behaviors. However, both empirical data and theoretical analysis have demonstrated that MFDs are expected to be uncertain due to inherent instabilities that exist in traffic networks. Fortunately, sufficient amounts of adaptive drivers who re-route to avoid congestion have been proven to help eliminate the instability of MFDs. Unfortunately, drivers cannot re-route themselves adaptively all the time as routing choices are controlled by multiple factors, and the presence of adaptive drivers is not something that traffic engineers can control. Since MFDs have shown promise in the design and control of urban networks, it is important to seek another strategy to mitigate or eliminate the instability of MFDs. Furthermore, it is necessary to develop a framework to account for the uncertain phenomena that emerges on the macroscopic, network-wide level to address these unavoidable stochastic behaviors.This first half of this work investigates another strategy to eliminate inherent network instabilities and produce more reliable MFDs that is reliable and controllable from an engineering perspective--the use of adaptive traffic signals. A family of adaptive signal control strategies is examined on two abstractions of an idealized grid network using an interactive simulation and analytical model. The results suggest that adaptive traffic signals should provide a stabilizing influence that provides more well-defined MFDs. Adaptive signal control also both increases average flows and decreases the likelihood of gridlock when the network is moderately congested. The benefits achieved at these moderately congested states increase with the level of signal adaptivity. However, when the network is extremely congested, vehicle movements become more constrained by downstream congestion and queue spillbacks than by traffic signals, and adaptive traffic signals appear to have little to no effect on the network or MFD. When a network is extremely congested, other strategies should be used to mitigate the instability, like adaptively routing drivers. Therefore, without sufficient amounts of adaptive drivers, the instability of MFDs could be somewhat controlled, but it cannot be eliminated completely. This is results in more reliable MFDs until the network enters heavily congested states. The second half of this work uses stochastic differential equations (SDEs) to depict the evolutionary dynamics of urban network while accounting for unavoidable uncertain phenomena. General analytical solutions of SDEs only exist for linear functions. Unfortunately, most MFDs observed from simulation and empirical data follow non-linear functions. Even the most simplified theoretical model is piecewise linear with breakpoints that cannot be readily accommodated by the linear SDE approach. To overcome this limitation, the SDE well-known solutions are used to develop an approximate solution method that relies on the discretization of the continuous state space. This process is memoryless and results in the development of a computationally efficient Markov Chain (MC) framework. The MC model is also supported by a well-developed theory which facilitates the estimation of future states or steady state equilibrium conditions in a network that explicitly accounts for MFD uncertainty. Due to the fact that current formalization of Markov Chains is restricted with a countable state space, some assumptions which redefine the traffic state and stochastic dynamic process need to be set for the MC model application in dynamic traffic analysis. These assumptions could be sabotaged by inappropriate parameter selections, producing excessive errors in analytical solutions. Therefore, a parametric study is performed here to illustrate how to select two key parameters, i.e. bin size and time interval to optimize the MC models and minimize errors.The major advantage of MC models is its wide flexibility, which has been demonstrated by showing how this method could well handle a wide variety of variables. A family of numerical tests are designed to include instability of MFD model, stochastic traffic demand, different city layouts and different forms of MFDs in the scenarios under static metering strategies. The results suggest that analytical solutions derived from MC models could accurately predict the future traffic state at any moment. Furthermore, the theoretical analysis also illustrates that Markov chains could easily model dynamic traffic control based on traffic state and pre-determined time-varying strategies by adjusting the transition matrix. Overall, the developed MC models are promising in the dynamic analysis of complicated urban network control under uncertainty for which simpler algebraic solutions do not exist.
Download or read book Models for Vehicular Traffic on Networks written by Mauro Garavello and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transportation and Traffic Theory 2009 Golden Jubilee written by William H. K. Lam and published by Springer Science & Business Media. This book was released on 2009-09-01 with total page 743 pages. Available in PDF, EPUB and Kindle. Book excerpt: th It is our great privilege and honor to present the proceedings of the 18 International Symposium on Transportation and Traffic Theory (ISTTT), held at The Hong Kong Polytechnic University in Hong Kong, China on 16-18 July 2009. th The 18 ISTTT is jointly organized by the Hong Kong Society for Transportation Studies and Department of Civil and Structural Engineering of The Hong Kong Polytechnic University. The ISTTT series is the main gathering for the world’s transportation and traffic theorists, and those who are interested in contributing to or gaining a deep understanding of traffic and transportation phenomena in order to better plan, design and manage the transportation system. Although it embraces a wide range of topics, from traffic flow theories and demand modeling to road safety and logistics and supply chain modeling, the ISTTT is hallmarked by its intellectual innovation, research and development excellence in the treatment of real-world transportation and traffic problems. The ISTTT prides itself in the extremely high quality of its proceedings. Previous ISTTT conferences were held in Warren, Michigan (1959), London (1963), New York (1965), Karlsruhe (1968), Berkeley, California (1971), Sydney (1974), Kyoto (1977), Toronto (1981), Delft (1984), Cambridge, Massachusetts (1987), Yokohama (1990), Berkeley, California (1993), Lyon (1996), Jerusalem (1999), Adelaide (2002), College Park, Maryland (2005), and London (2007). th th This 18 ISTTT celebrates the 50 Anniversary of this premier conference series.
Download or read book Simulation Approaches in Transportation Analysis written by Ryuichi Kitamura and published by Springer Science & Business Media. This book was released on 2006-03-10 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simulation Approaches in Transportation Analysis: Recent Advances and Challenges presents the latest developments in transport simulation, including dynamic network simulation and micro-simulation of people’s movement in an urban area. It offers a collection of the major simulation models that are now in use throughout the world; it illustrates each model in detail, examines potential problems, and points to directions for future development. The reader will be able to understand the functioning, applicability, and usefulness of advanced transport simulation models. The material in this book will be of wide use to graduate students and practitioners as well as researchers in the transportation engineering and planning fields.
Download or read book Modeling Travel Time in Urban Arterial Networks with Time variant Turning Movements Using State space Neural Networks written by Timothy Joseph Likens and published by . This book was released on 2007 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic Simulation and Data written by Winnie Daamen and published by CRC Press. This book was released on 2014-09-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: A single source of information for researchers and professionals, Traffic Simulation and Data: Validation Methods and Applications offers a complete overview of traffic data collection, state estimation, calibration and validation for traffic modelling and simulation. It derives from the Multitude Project—a European Cost Action project that incorporates work packages defining traffic simulation practice and research; highway and network modeling; and synthesis, dissemination, and training. This book addresses the calibration and validation of traffic models, and introduces necessary frameworks and techniques. It also includes viable methods for sensitivity analyses, and incorporates relevant tools for application. The book begins with a brief summary of various data collection techniques that can be applied to collect different data types. It then showcases various data processing and enhancement techniques for improving the quality of collected data. It also introduces the techniques according to the type of estimation, for example microscopic data enhancement, traffic state estimation, feature extraction and parameter identification techniques, and origin–destination matrix estimation. The material discusses the measures of performance, data error and goodness of fit, and optimization algorithms. It also contains the sensitivity analyses of parameters in traffic models. Describes the various tasks of calibration and validation Considers the best use of available data Presents the sensitivity analysis method Discusses typical issues of data error in transportation system data and how these errors can impact simulation results Details various methodologies for data collection, sensitivity analysis, calibration, and validation Examines benefits that result from the application of these methods Traffic Simulation and Data: Validation Methods and Applications serves as a key resource for transport engineers and planners, researchers, and graduate students in transport engineering and planning.
Download or read book The Network Reliability of Transport written by M. G. H. Bell and published by Elsevier. This book was released on 2003-05-08 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reliability of transportation networks has become an increasingly important issue as sustained economic growth and improvements to the quality of life around the world lead to increases in the value of time. Consequently, schedules and routes need to be able to accommodate the unexpected, like accidents, disasters or traffic flow fluctuations, with as little loss in operational efficiency as possible. Sources of unreliability include variation of demand and supply. It is widely expected that network reliability analysis will play a more important role in the planning, design and management of transportation facilities and networks in the future. This book is an outcome of the First International Symposium on Transport Network Reliability (INSTR), held at Kyoto in 2001, and consists of 24 selected papers. It covers various aspects of transport network reliability, such as definitions and methodological developments for reliability indices, behavioural analysis under uncertainty, evaluation methods for the disaster resistance of transport networks, and simulation/observation of travel time reliability.
Download or read book Linear and Non Linear Financial Econometrics written by Mehmet Terzioğlu and published by BoD – Books on Demand. This book was released on 2021-03-17 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of experimental economics and econometric methods increases with each passing day as data quality and software performance develops. New econometric models are developed by diverging from earlier cliché econometric models with the emergence of specialized fields of study. This book, which is expected to be an extensive and useful reference by bringing together some of the latest developments in the field of econometrics, also contains quantitative examples and problem sets. We thank all the authors who contributed to this book with their studies that provide extensive and accessible explanations of the existing econometric methods.
Download or read book Estimators of Travel Time for Road Networks written by Piet H. L. Bovy and published by . This book was released on 2000 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantifying Travel Time Variability in Transportation Networks written by Stephen David Boyles and published by . This book was released on 2010 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonrecurring congestion creates significant delay on freeways in urban areas, lending importance to the study of facility reliability. In locations where traffic detectors record and archive data, approximate probability distributions for travel speed or other quantities of interest can be determined from historical data; however, the coverage of detectors is not always complete, and many regions have not deployed such infrastructure. This report describes procedures for estimating such distributions in the absence of this data, considering both supply-side factors (reductions in capacity due to events such as incidents or poor weather) and demand-side factors (such as daily variation in travel activity). Two demonstrations are provided: using data from the Dallas metropolitan area, probability distributions fitting observed speed data are identified, and regression models developed for estimating their parameters. Using data from the Seattle metropolitan area, the appropriate capacity reduction applied to planning delay functions in the case of an incident is identified.
Download or read book Travel Time Prediction under Egypt Heterogeneous Traffic Conditions using Neural Network and Data Fusion written by Mohamed Zaki and published by Infinite Study. This book was released on with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cairo is experiencing traffic congestion that places it among the worst in the world. Obviously, it is difficult if not impossible to solve the transportation problem because it is multi-dimensional problem but it's good to reduce this waste of money and the associated waste of time resulting from congestion.
