Download or read book Investigation of Two regime Traffic Flow Models at Micro and Macroscopic Levels written by Avishai Ceder and published by . This book was released on 1975 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic Flow Modelling to Improve Traffic State Prediction written by Yuechuan Yin and published by . This book was released on 2014 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, the relationship between microscopic car-following models and macroscopic models has been explored and it was found that, based on the traditional assumption that traffic density is the reverse of space headway under steady-state homogeneous traffic conditions, most of the existing macroscopic speed-density relations can be derived from microscopic car-following models. The traditional assumption does not hold under non-homogeneous traffic and different macroscopic traffic models can be derived from different headway-density. The research also investigated the compatibility between the macroscopic and microscopic simulation. The microscopic simulation model, VISSIM, was calibrated and validated on an urban freeway. The VISSIM outputs were compared with the predicted traffic speed, density and flow from the second-order macroscopic model, METANET. Three levels of traffic demands and seven different time step lengths in macroscopic simulation were applied to evaluate the compatibility of the two models. It was concluded that, in macroscopic simulation, there exists an optimum time step length. Under moderate to heavy traffic demands, the predicted traffic states from the macroscopic simulation are consistent with the outputs from the microscopic simulation, and under stop-and-go traffic states, a significant difference exists between the two models. In addition, the impact of merging and weaving from freeway ramps on the performance of macroscopic simulation models was experimentally investigated. Several merging and weaving formulations in speed dynamics were evaluated and their contributions to the predicted traffic speed were quantitatively analyzed. Analysis of variances were carried out on the prediction errors from different models and it was concluded that, for the given formulation, the impact of merging and weaving terms on the prediction accuracy was not statistically significant, merging and weaving terms can be omitted in macroscopic simulation models. Finally, several improvements on the macroscopic simulation models were proposed. The improved models were applied to two freeways and compared with outputs from the original model, using both simulation data as well as field measured data from two freeways. It was concluded that the models with the proposed improvements have obviously better performance than the original model, especially in congested traffic conditions.
Download or read book Breakdown in Traffic Networks written by Boris S. Kerner and published by Springer. This book was released on 2017-05-26 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a detailed investigation of breakdowns in traffic and transportation networks. It shows empirically that transitions from free flow to so-called synchronized flow, initiated by local disturbances at network bottlenecks, display a nucleation-type behavior: while small disturbances in free flow decay, larger ones grow further and lead to breakdowns at the bottlenecks. Further, it discusses in detail the significance of this nucleation effect for traffic and transportation theories, and the consequences this has for future automatic driving, traffic control, dynamic traffic assignment, and optimization in traffic and transportation networks. Starting from a large volume of field traffic data collected from various sources obtained solely through measurements in real world traffic, the author develops his insights, with an emphasis less on reviewing existing methodologies, models and theories, and more on providing a detailed analysis of empirical traffic data and drawing consequences regarding the minimum requirements for any traffic and transportation theories to be valid. The book - proves the empirical nucleation nature of traffic breakdown in networks - discusses the origin of the failure of classical traffic and transportation theories - shows that the three-phase theory is incommensurable with the classical traffic theories, and - explains why current state-of-the art dynamic traffic assignments tend to provoke heavy traffic congestion, making it a valuable reference resource for a wide audience of scientists and postgraduate students interested in the fundamental understanding of empirical traffic phenomena and related data-driven phenomenology, as well as for practitioners working in the fields of traffic and transportation engineering.
Download or read book Mathematical Descriptions of Traffic Flow Micro Macro and Kinetic Models written by Gabriella Puppo and published by Springer Nature. This book was released on 2021-03-31 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book originates from the mini-symposium "Mathematical descriptions of traffic flow: micro, macro and kinetic models" organised by the editors within the ICIAM 2019 Congress held in Valencia, Spain, in July 2019. The book is composed of five chapters, which address new research lines in the mathematical modelling of vehicular traffic, at the cutting edge of contemporary research, including traffic automation by means of autonomous vehicles. The contributions span the three most representative scales of mathematical modelling: the microscopic scale of particles, the mesoscopic scale of statistical kinetic description and the macroscopic scale of partial differential equations.The work is addressed to researchers in the field.
Download or read book Traffic Flow Theory written by National Research Council (U.S.). Transportation Research Board and published by . This book was released on 1998 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Traffic written by Boris S. Kerner and published by Springer. This book was released on 2012-12-06 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: The core of ths book presents a theory developed by the author to combine the recent insight into empirical data with mathematical models in freeway traffic research based on dynamical non-linear processes.
Download or read book Validation and Evaluation of Freeway Simulation Models written by Michael James Cassidy and published by . This book was released on 1995 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transportation Research Record written by and published by . This book was released on 1994 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Data Fitted Generic Second Order Macroscopic Traffic Flow Models written by Shimao Fan and published by . This book was released on 2013 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Aw-Rascle-Zhang (ARZ) model has become a favorable ``second order" macroscopic traffic model, which corrects several shortcomings of the Payne-Whitham (PW) model. The ARZ model possesses a family of flow rate versus density (FD) curves, rather than a single one as in the ``first order" Lighthill-Whitham-Richards (LWR) model. This is more realistic especially during congested traffic state, where the historic fundamental diagram data points are observed to be set-valued. However, the ARZ model also possesses some obvious shortcomings, e.g., it assumes multiple maximum traffic densities which should be a ``property" of road. Instead, we propose a Generalized ARZ (GARZ) model under the generic framework of ``second order" macroscopic models to overcome the drawbacks of the ARZ model. A systematic approach is presented to design generic ``second order" models from historic data, e.g., we construct a family of flow rate curves by fitting with data. Based on the GARZ model, we then propose a phase-transition-like model that allows the flow rate curves to coincide in the free flow regime. The resulting model is called Collapsed GARZ (CGARZ) model. The CGARZ model keeps the flavor of phase transition models in the sense that it assume a single FD function in the free-flow phase. However, one should note that there is no real phase transition in the CGARZ model. To investigate to which extent the new generic ``second order" models (GARZ, CGARZ) improve the prediction accuracy of macroscopic models, we perform a comparison of the proposed models with two types of LWR models and their ``second order" generalizations, given by the ARZ model, via a three-detector problem test. In this test framework, the initial and boundary conditions are derived from real traffic data. In terms of using historic traffic data, a statistical technique, the so-called kernel density estimation, is applied to obtain density and velocity distributions from trajectory data, and a cubic interpolation is employed to formulate boundary condition from single-loop sensor data. Moreover, a relaxation term is added to the momentum equation of selected ``second order" models to address further unrealistic aspects of homogeneous models. Using these inhomogeneous ``second order" models, we study which choices of the relaxation term &tau are realistic.
Download or read book Highway Capacity and Traffic Flow written by National Research Council (U.S.). Transportation Research Board and published by . This book was released on 1992 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic Flow Dynamics written by Martin Treiber and published by Springer Science & Business Media. This book was released on 2012-10-10 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a comprehensive and instructive coverage of vehicular traffic flow dynamics and modeling. It makes this fascinating interdisciplinary topic, which to date was only documented in parts by specialized monographs, accessible to a broad readership. Numerous figures and problems with solutions help the reader to quickly understand and practice the presented concepts. This book is targeted at students of physics and traffic engineering and, more generally, also at students and professionals in computer science, mathematics, and interdisciplinary topics. It also offers material for project work in programming and simulation at college and university level. The main part, after presenting different categories of traffic data, is devoted to a mathematical description of the dynamics of traffic flow, covering macroscopic models which describe traffic in terms of density, as well as microscopic many-particle models in which each particle corresponds to a vehicle and its driver. Focus chapters on traffic instabilities and model calibration/validation present these topics in a novel and systematic way. Finally, the theoretical framework is shown at work in selected applications such as traffic-state and travel-time estimation, intelligent transportation systems, traffic operations management, and a detailed physics-based model for fuel consumption and emissions.
Download or read book An Introduction to Traffic Flow Theory written by Lily Elefteriadou and published by Springer Nature. This book was released on with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic Management Research at the University of California written by Adolf Darlington May and published by . This book was released on 1984 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Multi class Traffic Flow Models written by Yidi Chen and published by . This book was released on 2020 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic flow theory describes the behavior of vehicles systemically. The macroscopic traffic models consider the traffic as a continuum flow. Multi-class traffic models are a family of macroscopic models that divide the traffic platoon in different groups. Two multi-class traffic models, Wong’s model and FASTLANE model, are studied in this thesis. These two models employ different speed-density relations and methods to calculate total density of the continuum flow. Three numerical methods, including first-order Lax-Friedrichs method, second-order central-upwind method, and third-order discontinuous Galerkin method, are implemented to solve these models. The behaviors of Wong’s model and FASTLANE model under different parameter settings and numerical methods are analyzed and compared.
Download or read book Stochastic Two Dimensional Microscopic Traffic Model written by HongSheng Qi and published by Springer Nature. This book was released on with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic flow Models written by H. Botma and published by . This book was released on 1981 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Traffic Flow Theory and Applications written by National Research Council (U.S.). Transportation Research Board and published by Trb. This book was released on 1976 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
