Download or read book Developing Microscopic Traffic Simulation Models for the Transition Towards Automated Driving written by Ivan Postigo and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation and Queueing Network Model Formulation of Mixed Automated and Non automated Traffic in Urban Settings written by Nathaniel Karl Bailey and published by . This book was released on 2016 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Automated driving is an emerging technology in the automotive industry which will likely lead to significant changes in transportation systems. As automated driving technology is still in early stages of implementation in vehicles, it is important yet difficult to understand the nature of these changes. Previous research indicates that autonomous vehicles offer numerous benefits to highway traffic, but their impact on traffic in urban scenarios with mixed autonomous and non-autonomous traffic is less understood. This research addresses this issue by using microscopic traffic simulation to develop understanding of how traffic dynamics change as autonomous vehicle penetration rate varies. Manually driven and autonomous vehicles are modeled in a simulation environment with different behavioral models obtained from the literature. Mixed traffic is simulated in a simple network featuring traffic flowing through an isolated signalized intersection. The green phase length, autonomous vehicle penetration rate, and demand rate are varied. We observe an increase in network capacity and a decrease in average delay as autonomous vehicle penetration rate is increased. Using the results of the simulation experiments, an existing analytical network queueing model is formulated to model mixed autonomous and non-autonomous urban traffic. Results from the analytical model are compared to those from simulation in the small network and the Lausanne city network, and they are found to be consistent.

Download or read book Transport Simulation written by Edward Chung and published by CRC Press. This book was released on 2019-05-07 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the transport simulation of large road networks has become far more rapid and detailed, and many exciting developments in this field have emerged. Within this volume, the authors describe the simulation of automobile, pedestrian, and rail traffic coupled to new applications, such as the embedding of traffic simulation into driving simulators, to give a more realistic environment of driver behavior surrounding the subject vehicle. New approaches to traffic simulation are described, including the hybrid mesoscopic-microscopic model and floor-field agent-based simulation. Written by an invited panel of experts, this book addresses students, engineers, and scholars, as well as anyone who needs a state-of-the-art overview of transport simulation today.

Download or read book Developing a Methodology to Account for Commercial Motor Vehicles Using Microscopic Traffic Simulation Models microform written by Schultz, Grant George and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The collection and interpretation of data is a critical component of traffic and transportation engineering used to establish baseline performance measures and to forecast future conditions. One important source of traffic data is commercial motor vehicle (CMV) weight and classification data used as input to critical tasks in transportation design, operations, and planning. The evolution of Intelligent Transportation System (ITS) technologies has been providing transportation engineers and planners with an increased availability of CMV data. The primary sources of these data are automatic vehicle classification (AVC) and weigh-in-motion (WIM). Microscopic traffic simulation models have been used extensively to model the dynamic and stochastic nature of transportation systems including vehicle composition. One aspect of effective microscopic traffic simulation models that has received increased attention in recent years is the calibration of these models, which has traditionally been concerned with identifying the "best" parameter set from a range of acceptable values. Recent research has begun the process of automating the calibration process in an effort to accurately reflect the components of the transportation system being analyzed. The objective of this research is to develop a methodology in which the effects of CMVs can be included in the calibration of microscopic traffic simulation models. The research examines the ITS data available on weight and operating characteristics of CMVs and incorporates this data in the calibration of microscopic traffic simulation models. The research develops a methodology to model CMVs using microscopic traffic simulation models and then utilizes the output of these models to generate the data necessary to quantify the impacts of CMVs on infrastructure, travel time, and emissions. The research uses advanced statistical tools including principal component analysis (PCA) and recursive partitioning to identify relationships between data collection sites (i.e., WIM, AVC) such that the data collected at WIM sites can be utilized to estimate weight and length distributions at AVC sites. The research also examines methodologies to include the distribution or measures of central tendency and dispersion (i.e., mean, variance) into the calibration process. The approach is applied using the CORSIM model and calibrated utilizing an automated genetic algorithm methodology.

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 An Evaluation of Traffic Simulation Models for Supporting ITS Development written by Sharon Adams Boxill and published by . This book was released on 2000 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tools to evaluate networks under information supply are a vital necessity in light of the systems being implemented as part of the Intelligent Transportation Systems (ITS) deployment plan. One such tool is the traffic simulation model. This report presents an evaluation of the existing traffic simulation models to identify the models that can be potentially applied in ITS equipped networks. The traffic simulation models are categorized according to type (macroscopic, microscopic or mesoscopic), as well as functionality (highway, signal, integrated). The entire evaluation is conducted through two steps: initial screening and in-depth evaluation. The initial step generates a shorter but more specific list of traffic simulation models based on some pre-determined criteria. The in-depth evaluation identifies which model on the shorter list is suitable for a specific area of ITS applications. It is concluded from this research that presently CORSIM and INTEGRATION appear to have the highest probability of success in real-world applications. It is also found that by adding more calibration and validation in the U.S., the AIMSUN 2 and PARAMICS models will be brought to the forefront in the near term for use with ITS applications.

Download or read book Towards Developing an Integrated Microscopic Traffic Simulation Model for Large Road Networks written by Frank Lehmann and published by . This book was released on 2018 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic jams have become one of the key topics in the 21st century and cause immense losses in productivity, increase CO2 emissions and affect driver stress, travel time predictability and increased wear and tear on vehicles. To test possible countermeasures, optimise existing infrastructure or develop new Intelligent Transport Systems (ITS), traffic has to be modelled. The inherent complexity which is a result of inter- and intra-driver heterogeneity, macroscopic feedback loops, local interactions, multi-modal transport and many more is tackled with simulations. By representing the (longitudinal) dynamics of individual vehicles (“microsimulation”), high model fidelity can be achieved. By aggregating the resulting trajectories, macroscopic phenomena emerge and can be incorporated to answer a wide range of traffic-related questions. Since human drivers vary in their perception of stimuli, preferences and reaction, randomness is inevitably and circumvents the construction of perfectly accurate models. Which microscopic features are needed and how they should be mathematically represented runs like a central thread through this thesis. First, it develops a systematic classification scheme to identify modelling strategies and evaluate advantages and shortcomings of (partly) discrete microsimulations. Because real-world trajectories are continuous in time and space, representing them discretely leads to artefacts which induces an upper precision boundary for all models operating on this level of discretisation. Such model-independent errors will be measured based on empirical, naturalistic and synthetically generated trajectories. It is also evaluated to which extent driver heterogeneity and randomness may be compensated with discrete components to simplify modelling and increase computational efficiency. Based on the gained insights, a new, integrated microscopic model is developed. The second major theme in this thesis are gridded, discrete road topologies (chequerboards, Manhattan layouts) populated with vehicles “hopping” from one location to the next. An extensive literature review summarise existing approaches and it is discussed how these standardised road networks and extremely simplified dynamics are well-suited as testbed for ITS. Based on identified research gaps a Timed Automata-based particle hopping model is developed. The two main tools to achieve the outlined objectives are literature reviews, data analysis and computer simulations. To construct the classification scheme, existing genealogies and typologies for traffic models and dynamical systems in other scientific disciplines were reviewed. Another approach was taken for conducting the literature review of chequerboard models: starting from the prototypical BML model, the citing sources are surveyed in reverse order, the behaviour of relevant models is synthesized and contradictions and gaps critically analysed. To quantify the model-independent error, datasets are sampled, quantised and discretised over a wide range of step sizes. Making use of naturalistic driving data, synthetically generated trajectories and high-quality experimental observations, the highest achievable errors for (partly) discrete microsimulations is measured. The dataset recorded under experimental conditions with a group of homogeneous drivers is reused to identify to quantify driver heterogeneity and find the maximum achievable correlations between car-following stimuli and reactions. In summary, this thesis shows that randomness and heterogeneity in human drivers is significant and exceeds the model-independent discretisation errors for a wide range of quantisation parameters. This justifies representing trajectory features discretely to increase computational efficiency and improve the modelling process. Based on this proposition two new formulations for simplistic and advanced microsimulations are developed. The former is able to reproduce all macroscopic free-flow to congestion phase transitions while the latter integrates lateral and longitudinal dynamics based on statistical microscopic properties. Both approaches fill gaps identified by a systematic literature review.

Download or read book Mobility and Safety Implications of Automated Vehicles in Mixed Traffic by Recognizing Behavioral Variations of Drivers written by Mudasser Seraj and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Introduction of Connected-Automated Vehicle (CAV) technology provided a new opportunity to fix the traditional transportation system. Automated vehicles (AuV) would take the driving responsibility and drive the vehicles by analyzing their' surrounding through a range of sensors. The connectivity feature of these vehicles would facilitate to sense of the roadway and traffic conditions beyond the range of sensors and make informed decisions. While the vehicles equipped with these technologies becoming more common, large-scale market penetration will take a long time. Hence, our transportation infrastructure will pass through a transitional phase where both Human-driven vehicles (HuV) and AuVs share the roadway. Additionally, the prosperity and acceptance of these technologies depend on a clear understanding of the implications of overcoming the limitations of the traditional transportation system. My research focused on developing a comprehensive modeling framework to establish numerical simulation of both types of vehicles (i.e., HuVs, AuVs ) while recognizing the variations of driving behaviors of human drivers. Modeling both vehicle types provided the opportunity to explore diverse mixed traffic scenarios to attain extensive insights into such traffic conditions. Prior to developing the modeling framework, the variations of the human driving patterns were identified through extensive analysis of real-world human driving data. Bi-directional (i.e., longitudinal, lateral) control features were analyzed to comprehend human instincts during driving which can be integrated with the human driver modeling. Further analysis was performed to classify driving behaviors based on these features for the short and long term. The upsides of studying human driving behavior rest not only on better understanding for modeling human drivers but also on designing automated vehicles capable of addressing the variations of human driver behavior. The behavioral classification approach in this part of the research used three vehicular features known as jerk, leading headway, and yaw rate to classify human drivers into two groups (Safe and Hostile Driving) on short-term classification, and drivers' habits are categorized into three classes (Calm Driver, Rational Driver, and Aggressive Driver). Through the proposed method, behavior classification has been successfully identified in 86.31 ± 9.84% of speeding and 87.92 ± 10.04% of acute acceleration instances. Afterward, the foundation of mixed traffic modeling was developed through car-following strategy formulation. This part of the research proposes a naïve microscopic car-following strategy for a mixed traffic stream in CAV settings and measured shifts in traffic mobility and safety as a result. Additionally, this part of the research explores the influences of platoon properties (i.e. Intra-platoon Headway, Inter-platoon Headway, Maximum Platoon Length) on traffic stream characteristics. Different combinations of HuVs and AuVs are simulated in order to understand the variations of improvements induced by AuVs in a traffic stream. Simulation results reveal that grouping AuVs at the front of the traffic stream to apply CACC-based car-following model will generate maximum mobility benefits for the traffic. Higher mobility improvements can be attained by forming long, closely spaced AuVs at the cost of reduced safety. To achieve balanced mobility and safety advantages from mixed traffic movements, dynamically optimized platoon configurations should be determined at varying traffic conditions and AuVs market penetrations. Finally, grounded on prior research on human driving behavior and modeling framework of mixed traffic, this research objectively experimented with bi-directional motion dynamics in a microscopic modeling framework to measure the mobility and safety implications for mixed traffic movement in a freeway weaving section. This part of research begins by establishing a multilane microscopic model for studied vehicle types from model predictive control with the provision to form a CACC platoon of AuV vehicles. The proposed modeling framework was tested first with HuV only on a two-lane weaving section and validated using standardized macroscopic parameters from the HCM. This model was then applied to incrementally expand the AuV share for varying inflow rates of traffic. Simulation results showed that the maximum flow rate through the weaving section was attained at a 65% AuV share while steadiness in the average speed of traffic was experienced with increasing AuV share. Finally, the results of simulated scenarios were consolidated and scaled to report expected mobility and safety outcomes from the prevailing traffic state as well as the optimal AuV share for the current inflow rate in weaving sections.

Download or read book Microscopic Traffic Simulation written by Swe-Kuang Tan and published by . This book was released on 2001 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document details the development of a Virtual Reality (VR) traffic simulator that models flow dynamics at vehicle-level, or "Microscopic," granularity. Plausible vehicle behavior, coupled with rich graphics and intuitive interaction modes, gives the user an accurate sense of realism and provides a tool with unmatched capabilities, whether used for roadway planning, design, or communications. The simulator may operate in either a console mode (for desktop viewing), or in full-immersion mode in a six-sided VR environment. In a departure from other efforts in this class, i.e. Microscopic simulations, the work attempts to capture a fuller range of driving behavior by adopting a hierarchical model of the human decision-making process, i.e., strategic, tactical and control. Specifically, our effort makes the following contributions: proposed a "fuzzy", or knowledge-based, controller to model the strategic layer (e.g., navigation, route planning); upgraded an existing roadway editor by adding new, and enhancing existing, functionalities; and provided a networked run-time environment to contain the microscopic simulation.

Download or read book Cooperative Traffic Control Framework for Mixed Vehicular Flows written by Mohammad Karimi and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A prompt revolution is foreseen in the transportation sector, when the current conventional human-driven vehicles will be replaced by fully connected and automated vehicles. As a result, there will be a transition period where both types will coexist until the later type is fully adopted in the traffic networks. This new mix of traffic flow on the existing transportation network will require developing a new ecosystem able to accommodate both types of vehicles in traffic network environments of the future. A major challenging issue related to the emerging mixed transportation ecosystem is the lack of an adequate model and control framework. This is especially important for modeling traffic safety and operations at network bottlenecks such as highway merging areas. Therefore, the main goal of this thesis is to develop a microscopic modeling and hierarchical cooperative control framework specifically for mixed traffic at highway on-ramps. In this thesis, a two-level hierarchical traffic control framework is proposed for mixed traffic at highway merging areas. In this regard, for the lower level of the proposed framework, this thesis establishes a set of fundamental trajectory-based cooperative control algorithms for different merging scenarios under mixed traffic conditions. We identify six scenarios, consisting of triplets of vehicles, defined based on the different combinations of CAVs and conventional vehicles. For each triplet, different consecutive movement phases along with corresponding desired distance and velocity set-points are defined. Via the movement phases, the CAVs engaged in each triplet cooperate to calculate their optimal-smooth trajectories aiming at facilitating the merging maneuver while complying with the realistic constraints related to the safety and comfort of vehicle occupants. The vehicles in each triplet are modeled by a distinct system, and a Model Predictive Control scheme is employed to calculate the cooperative optimal control inputs (acceleration values) for CAVs, accounting for conventional vehicles' uncertainties. In the next step of the thesis, for the higher level of the proposed framework, a merging sequence determination and triplets' formation methodology is developed based on predicting the arrival time of vehicles into the merging area and according to the priority in choosing different triplet types. To model the merging maneuvers when two consecutive triplets share a vehicle, the interactions between triplets of vehicles are also investigated. In order to develop a microscopic traffic simulator, we analytically formulate different vehicles' driving behaviors under cooperative (i.e., the proposed traffic control framework) and non-cooperative (i.e., normal) operation modes and discuss the switching conditions between these driving modes. To evaluate the effectiveness of the proposed framework, first, each triplet is simulated in MATLAB and evaluated for different sets of system initial values. Without a need for readjusting the algorithm for different initial values, the simulation results show that the proposed cooperative merging algorithms ensure smooth merging maneuvers while satisfying all the prescribed constraints, e.g., speed limits, safe distances, and comfortable acceleration and jerk values. Moreover, a simulator is developed in MATLAB for the entire framework (including both the higher and lower level of the framework) to evaluate the impact of all the triplets on continuous mixed traffic flow. Different penetration rates of CAVs under different traffic flow conditions are evaluated through the developed simulator. The simulation results show that the proposed cooperative methodology, comparing to the non-cooperative operation, can improve the average travel time of merging vehicles without disturbing the mainstream flow, provide safer merging maneuvers by avoiding the merging vehicles to stop at the end of the acceleration lane, and guarantee smooth motion trajectories for CAVs (i.e., derivable position and speed along with limited changes in acceleration values). Generally, the results emphasize that the proposed cooperative traffic control framework can improve the mixed traffic conditions in terms of both traffic safety and operations. Moreover, the simulator provides a tool for the transportation community to evaluate their existing infrastructures under different penetration rates of CAVs and examine different traffic control plans for a mixed traffic environment. As the merging maneuver is only one application of gap-acceptance models, other types of maneuvers (e.g., lane changing, vehicle turning, etc.) can be similarly modelled. Thus, we can extend the proposed framework to the multi-lane highways, roundabouts, and urban area intersections. Furthermore, the arrival time prediction of the vehicles can be improved to elevate the performance of the proposed framework during the very congested traffic conditions.

Download or read book Stochastic Two dimensional Microscopic Traffic Model written by HongSheng QI and published by Springer. This book was released on 2024-08-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microscopic traffic model serves as the foundation of traffic flow theory and is the basis for applications such as traffic simulation, autonomous vehicle simulation, and digital twin technology. Conventional traffic models have primarily focused on the longitudinal dimension and have been deterministic in nature. However, vehicles' movements involve both longitudinal and lateral dimensions, and their dynamics are inherently stochastic. Therefore, a two-dimensional treatment is essential. This book explores the theory and application of stochastic two-dimensional microscopic traffic models, including the development of theory, establishment of methods, and applications to autonomous vehicles. The book is organized into three sections: data, theory, and application. In the data section, various open-source trajectory data are analyzed and noise reduction techniques are discussed. In the theory section, various two-dimensional traffic models are developed. In the application section, the potential applications of these models are discussed, including behavioral inferences and lateral wandering. This book will be a useful reference for students, researchers and engineers in the fields of vehicle engineering and traffic technology.

Download or read book Modelling and implementation of a microscopic traffic simulation system written by Johannes Brügmann and published by Logos Verlag Berlin GmbH. This book was released on 2015-11-16 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the foundations, the initial state, and the progress made in modelling and implementing a real-world and real-time online microscopic traffic simulation system for highway traffic. To successfully model and implement such a simulation system, this thesis recommends the use of a number of formal methods applied at the right places. As part of the recommendation, this thesis proposes a microscopic traffic simulation system. To explore the feasibility and the potential of the recommended methods, it observes and examines the proposed system from multiple views and under various different aspects. As part of the examination, this thesis provides a (semi-)formal specification, a model implementation, an implementation of a productive system, and the benefits that result from validating such a system. The results and any proper application of them have the potential to increase the reliability and the trustworthiness for any future implementation of the proposed simulation system. The presented results additionally motivate to apply the proposed approach to similar simulation systems. The thesis concludes the presentation of the results with some considerations for future implementations.

Download or read book Development and Evaluation of a Calibration and Validation Procedure for Microscopic Simulation Models written by Brian Park and published by . This book was released on 2004 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microscopic traffic simulation models have been widely accepted and applied in transportation engineering and planning practice for the past decades because simulation is cost-effective, safe, and fast. To achieve high fidelity and credibility for a traffic simulation model, calibration and validation are of utmost importance. Most calibration efforts reported in the literature have focused on the informal practice with a specific simulation model, but seldom did they propose a systematic procedure or guideline for simulation model calibration and validation. The purpose of this study was to develop and evaluate a procedure for microscopic simulation model calibration and validation. Three widely used microscopic traffic simulation models, VISSIM, PARAMICS, and CORSIM, were selected for model review and practice of model calibration and validation. The validity of the proposed procedure was evaluated and demonstrated via two case studies including an actuated signalized intersection and a 5-mile freeway segment with a lane-closure work zone. The simulation results were compared against the field data to determine the performance of the calibrated models. The proposed procedure yielded acceptable results for all applications, thus confirming that it was effective for the different networks and simulation models used in the study. Although the calibrated parameters generated the performance measures that were representative of the field conditions, the simulation results of the default parameters were significantly different from the field data.

Download or read book A Guide to Documenting Vissim based Microscopic Traffic Simulation Models written by and published by . This book was released on 2007 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Traffic Management Simulation Development written by Mohammed Abdul Hadi and published by . This book was released on 2011 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project is to explore the development of methods and tools for the use of microscopic traffic simulation models to support the traffic management center (TMC) software implementation, operation, and testing on the one hand, and the use of Intelligent Transportation System (ITS) data to support the development and calibration of simulation models on the other. The project products include software utilities that use the existing TMC databases and other available information for the preparation and calibration of microscopic simulation tools. In addition, the products include utilities to support testing of the TMC software modules and data archiving processes, as demonstrated by use cases of the tools developed in this study.

Download or read book Traffic Flow Dynamics written by Martin Treiber and published by Springer Science & Business Media. This book was released on 2012-10-11 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 Development of a Microscopic Traffic Simulation Model for Safety Assement of Signalized Intersections written by Minh Tan Dang and published by . This book was released on 2012 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: