Download or read book Modeling Traffic Through Intersections written by Mark Griffith and published by . This book was released on 2015 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper analyzes the effects traffic flow controllers, such as stop signs and stop lights, have on the flow of traffic through a 4-way intersection. In particular, we investigate which controller (either using 2 stop signs, 4 stop signs, or stop lights) to use depending on the number of cars in a lane. We use a method that accounts for a set number of cars in each lane and a car's velocity based on the distance to the stop line or to the car in front. We also account for how a car will turn once it reaches the stop line. When a car stops at an intersection, we change our model depending on the traffic flow controller being used. With stop signs, a car must first stop and can only proceed when certain cars have cleared the intersection. With lights, a car must wait for the appropriate light to turn green before the car can continue moving. In the end, we found it best to use 2 stop signs when there are less than 20 cars in each lane, stop lights when there are more than 30 cars in each lane, and 4 stop signs otherwise.

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 Modeling Simulation and Optimization of Traffic Intersections Using Petri Nets written by Aja Anjilivelil and published by . This book was released on 2015 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the increasing number of vehicles on the road and the amount of time people spend driving their vehicles, traffic control and management has become an important part within logistics. Effective traffic control would involve traffic signal control and control over vehicle movement. Since Petri nets are versatile enough to represent traffic signals and traffic flow, it has become an important tool in urban traffic control. Many traffic systems are modeled using hybrid Petri nets. Chapter 1 briefly talks about traffic management systems and previous related work in the area of traffic control. Chapter 2 is a basic background on various Petri nets used in the study. The section also uses examples to demonstrate the working of Petri nets. Chapter 3 introduces the need for optimization in various industry. And then, it discusses different steps involved in optimizing a process. Chapter 4 discusses the existing model of two one-way intersection. In an effort to understand the model better, simulations are also carried out. Then, drawbacks of the existing model are discussed. This paves way for a new, improved, and realistic version of two one-way intersection. Various optimization steps discussed in Chapter 3 is used to optimize traffic light of the improved model. And then, a comparison between existing model and improved model is carried out. Chapter 5 expands the study of traffic models by connecting two different one-way intersection through a road (thus making it a network). Optimization and simulation of the connected-intersection model is also carried out. Chapter 6 is the summary which will provide a brief overview about each chapter.

Download or read book Computational Logistics written by Tolga Bektaş and published by Springer. This book was released on 2017-10-11 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 8th InternationalConference on Computational Logistics, ICCL 2017, held in Southampton,UK, in October 2017.The 38 papers presented in this volume were carefully reviewed and selected for inclusion in the book. They are organized in topical sections entitled: vehicle routing and scheduling; maritime logistics;synchromodal transportation; and transportation, logistics and supply chain planning.

Download or read book Traffic Operations at Intersections written by Rod Troutbeck and published by . This book was released on 2020-06-03 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic Operations at Intersections: Learning and Applying the Models and Methods of the Highway Capacity Manual Chapters on all-way stop-controlled intersections, two-way stop-controlled intersections, and signalized intersections Designed for practicing transportation engineers and university seniors and graduate students 11 simplified scenarios to open-up your understanding of the HCM 43 example calculations that are fully worked out and explained in detail 7 computational engines that allow you to see inside and then apply the models 138 figures to clearly illustrate concepts Additional problems online The models of the Highway Capacity Manual (HCM) are often the engineer's choice to analyze intersection performance. These models are complex, and nearly all transportation engineers use software implementations of these models to conduct their analyses. Software applications are powerful tools that help engineers solve problems. But these applications also serve as barriers to the understanding of the complex models embedded in the software. Our major objective in writing this book is to transform the "black box" of the HCM intersection models, and their software implementations, into a "clear box" that allows the engineer to better understand how these models work. We do this through the idea of the "simplified scenario." The eleven scenarios that we present are based on conditions greatly simplified from what you would normally see in the field. By focusing on one concept at a time, in the context of these simplified conditions, you will better understand the fundamentals of the HCM intersection models. You will then be able to apply these models to more complex intersections with skill, confidence, and insight.

Download or read book Fundamentals of Traffic Simulation written by Jaume Barceló and published by Springer Science & Business Media. This book was released on 2011-01-06 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing power of computer technologies, the evolution of software en- neering and the advent of the intelligent transport systems has prompted traf c simulation to become one of the most used approaches for traf c analysis in s- port of the design and evaluation of traf c systems. The ability of traf c simulation to emulate the time variability of traf c phenomena makes it a unique tool for capturing the complexity of traf c systems. In recent years, traf c simulation – and namely microscopic traf c simulation – has moved from the academic to the professional world. A wide variety of traf- c simulation software is currently available on the market and it is utilized by thousands of users, consultants, researchers and public agencies. Microscopic traf c simulation based on the emulation of traf c ows from the dynamics of individual vehicles is becoming one the most attractive approaches. However, traf c simulation still lacks a uni ed treatment. Dozens of papers on theory and applications are published in scienti c journals every year. A search of simulation-related papers and workshops through the proceedings of the last annual TRB meetings would support this assertion, as would a review of the minutes from speci cally dedicated meetings such as the International Symposiums on Traf c Simulation (Yokohama, 2002; Lausanne, 2006; Brisbane, 2008) or the International Workshops on Traf c Modeling and Simulation (Tucson, 2001; Barcelona, 2003; Sedona, 2005; Graz 2008). Yet, the only comprehensive treatment of the subject to be found so far is in the user’s manuals of various software products.

Download or read book Stochastic Models in Traffic Flow Theory Intersection Control written by John Paul Lehoczky and published by . This book was released on 1969 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Traffic Flow Through Signalized Intersection written by Wan Asma Awatif Wan Daud and published by . This book was released on 2010 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Intersection Crash Counts and Traffic Volume written by Hans C. Joksch and published by . This book was released on 1998 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Operation Analysis and Design of Signalized Intersections written by Michael Kyte and published by Createspace Independent Publishing Platform. This book was released on 2014-07-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Before they begin their university studies, most students have experience with traffic signals, as drivers, pedestrians and bicycle riders. One of the tasks of the introductory course in transportation engineering is to portray the traffic signal control system in a way that connects with these experiences. The challenge is to reveal the system in a simple enough way to allow the student "in the door," but to include enough complexity so that this process of learning about signalized intersections is both challenging and rewarding. We have approached the process of developing this module with the following guidelines: * Focusing on the automobile user and pretimed signal operation allows the student to learn about fundamental principles of a signalized intersection, while laying the foundation for future courses that address other users (pedestrians, bicycle riders, public transit operators) and more advanced traffic control schemes such as actuated control, coordinated signal systems, and adaptive control. * Queuing models are presented as a way of learning about the fundamentals of traffic flow at a signalized intersection. A graphical approach is taken so that students can see how flow profile diagrams, cumulative vehicle diagrams, and queue accumulation polygons are powerful representations of the operation and performance of a signalized intersection. * Only those equations that students can apply with some degree of understanding are presented. For example, the uniform delay equation is developed and used as a means of representing intersection performance. However, the second and third terms of the Highway Capacity Manual delay equation are not included, as students will have no basis for understanding the foundation of these terms. * Learning objectives are clearly stated at the beginning of each section so that the student knows what is to come. At the end of each section, the learning objectives are reiterated along with a set of concepts that students should understand once they complete the work in the section. * Over 70 figures are included in the module. We believe that graphically illustrating basic concepts is an important way for students to learn, particularly for queuing model concepts and the development of the change and clearance timing intervals. * Over 50 computational problems and two field exercises are provided to give students the chance to test their understanding of the material. The sequence in which concepts are presented in this module, and the way in which more complex ideas build on the more fundamental ones, was based on our study of student learning in the introductory course. The development of each concept leads to an element in the culminating activity: the design and evaluation of a signal timing plan in section 9. For example, to complete step 1 of the design process, the student must learn about the sequencing and control of movements, presented in section 3 of this module. But to determine split times, step 6 of the design process, four concepts must be learned including flow (section 2), sequencing and control of movements (section 3), sufficiency of capacity (section 6), and cycle length and splits (section 8). Depending on the pace desired by the instructor, this material can be covered in 9 to 12 class periods.

Download or read book Modeling Traffic Accidents at Signalized Intersections in the City of Norfolk VA written by Sharad K. Maheshwari and published by . This book was released on 2010 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This study was an attempt to apply a proactive approach using traffic pattern and signalized intersection characteristics to predict accident rates at signalized intersections in a city's arterial network. An earlier analysis of accident data at selected intersections within the City of Norfolk indicated that in addition to traffic volume, other controllable factors contributed to traffic accidents at specific intersections. These factors included area topography, lane patterns, type of road signs, turning lanes, etc. It is also known that administrative factors such as signal types, signal polic[i]es, road closures, etc., and maintenance factors such as road conditions, condition of the signals, condition of road signs, etc. also impact road accidents. / The objective of this study was to relate these variables to accident rate and delineate variables that are statistically more significant for accident rate. Data on several topographical variables was collected in the City of Norfolk. These variables included number of lanes, turn lanes, pedestrian crossing, restricted lanes, etc. A linear regression model was used to establish relationship between these variables and the accident rate. The resulting regression model explained 60% of the variability. It also showed that four topographical variables are more important than other variables. Those variables included number of lanes, number of turn lanes, presence of median and presence of permanent hazard like railway crossing. However, validation of model showed higher than expected variation. The model developed, in this study, overestimates the accident rate by 33% thus, limiting its practical application."--Executive summary (p. 1).

Download or read book Observation and Modeling of Traffic Operations at Intersections in Malfunction Flash Mode written by Peter M. Jenior and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: When a traffic signals malfunction monitoring unit detects a problem with a traffic signal such as the simultaneous display of green indications to conflicting movements or loss of power to some signal heads, the signal is automatically placed into flash mode as a safety precaution. Signals can have either red/red malfunction flash mode or yellow/red malfunction flash mode, and the mode cannot change by time of day or day of week. This study analyzed traffic operation at 34 instances of yellow/red malfunction flash and 9 instances of red/red malfunction flash in the Atlanta, Georgia area. Many of these instances were during high volume periods. A high level of driver confusion exists at malfunction flash intersections. The rate at which through major street drivers (i.e. those facing a flashing yellow signal) stopped exceeded 75 percent at some yellow/red flash intersections. This creates a safety hazard for other major street drivers who are not expecting vehicles to stop, and for minor street drivers who cannot tell what type of control is being presented to cross traffic or do not understand that vehicles are not required to stop when approaching a flashing yellow indication. Furthermore, high stopping rates at a flashing yellow signal eliminate many of the operational benefits that yellow/red flash is assumed to have over red/red flash. Based on the findings of this study, the use of red/red flash should be the primary flash mode and possibly used exclusively. Requiring all vehicles to stop will improve safety conditions and not have large operational impacts at intersections where a majority of major street vehicles are already stopping at a flashing yellow signal. Yellow/red flash may be an acceptable malfunction flash mode at the intersection of a very large street and a very small street, but additional measures would be required at these intersections to address potential driver confusion.

Download or read book Traffic Modeling and Mitigation Measures for Signalized Intersections Along Corniche El Mazraa written by Mohammad Saad and published by . This book was released on 2016 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Traffic Modeling and Control at Intelligent Intersections written by Jinjian Li and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The traffic congestion is one of the most serious problems limiting the improvement of standing of life. The intersection is a place where the jams occur the most frequently. Therefore, it is more effective and economical to relieve the problem of the heavy traffic delays by ameliorating the traffic control strategies, instead of extending the infrastructures.The proposed method is a cooperative modeling to solve the problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). The resolution contains two main steps. The first step concerns the itinerary. An itinerary presents a list of intersections chosen by vehicles to arrive at their destinations from their origins. The second step is related to the following proposed cooperative procedures to make vehicles to pass through each intersection rapidly and economically: on the one hand, according to the real-time information sent by vehicles in the edge of the communication zone via V2I, each intersection applies Dynamic Programming (DP) or Artificial Bee Colony (ABC) to cooperatively optimize the vehicle passing sequence in intersection with the minimal time delay under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search.A series of simulation are executed under different traffic volumes to present the performance of proposed method. The results are compared with other control methods and research papers to prove the our new traffic control strategy.

Download or read book Modeling Estimation and Control of Traffic written by Dongyan Su and published by . This book was released on 2014 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation studies a series of freeway and arterial traffic modeling, estimation and control methodologies. First, it investigates the Link-Node Cell Transmission Model's (LN-CTM's) ability to model arterial traffic. The LN-CTM is a modification of the cell transmission model developed by Daganzo. The investigation utilizes traffic data collected on an arterial segment in Los Angeles, California, and a link-node cell transmission model, with some adaptations to the arterial traffic, is constructed for the studied location. The simulated flow and the simulation travel time were compared with field measurements to evaluate the modeling accuracy. Second, an algorithm for estimating turning proportions is proposed in this dissertation. The knowledge about turning proportions at street intersections is a frequent input for traffic models, but it is often difficult to measure directly. Compared with previous estimation methods used to solve this problem, the proposed method can be used with only half the detectors employed in the conventional complete detector configuration. The proposed method formulates the estimation problem as a constrained least squares problem, and a recursive solving procedure is given. A simulation study was carried out to demonstrate the accuracy and efficiency of the proposed algorithm. In addition to addressing arterial traffic modeling and estimation problems, this dissertation also studies a freeway traffic control strategy and a freeway and arterial coordinated control strategy. It presents a coordinated control strategy of variable speed limits (VSL) and ramp metering to address freeway congestion caused by weaving effects. In this strategy, variable speed limits are designed to maximize the bottleneck flow, and ramp metering is designed to minimize travel time in a model predictive control frame work. A microscopic simulation based on the I-80 at Emeryville, California was built to evaluate the strategy, and the results showed that the traffic performance was significantly improved . Following the freeway control study, this dissertation discusses the coordinated control of freeways and arterials. In current practice, traffic controls on freeways and on arterials are independent. In order to coordinate these two systems for better performance, a control strategy covering the freeway ramp metering and the signal control at the adjacent intersection is developed. This control strategy uses upstream ALINEA, which is a well-known control algorithm, for ramp metering to locally maximize freeway throughput. For the intersection signal control, the proposed control strategy distributes green splits by taking into account both the available on-ramp space and the demands of all intersection movements. A microscopic simulation of traffic in an arterial intersection with flow discharge to a freeway on-ramp, which is calibrated using the data collected at San Jose, California, is created to evaluate the performance of the proposed control strategy. The results showed that the proposed strategy can reduce intersection delay by 8%, compared to the current field-implemented control strategy. Transportation mobility can be improved not only by traffic management strategies, but also through the deployment of advanced vehicle technologies. This dissertation also investigates the impact of Adaptive Cruise Control (ACC) and Cooperative Adaptive Cruise Control (CACC) on highway capacity. A freeway microscopic traffic simulation model is constructed to evaluate how the freeway lane flow capacity change under different penetration rates of vehicles equipped with either ACC or CACC system. This simulation model is based on a calibrated driver behavioral model and the vehicle dynamics of the ACC and CACC systems. The model also utilizes data collected from a real experiment in which drivers' selections of time gaps are recorded. The simulation shows that highway capacity can be significantly increased when the CACC vehicles reach a moderate to high market penetration, as compared to both regular manually driven vehicles and vehicles equipped with only ACC.

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 Using Agent based Vehicle Traffic Models to Analyze Traffic Flow written by Michael Duff and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis discusses the creation of an agent-based model for vehicle traffic that uses a previously developed mathematical car-following micro-simulation model. The agent-based model results are verified against the original model. The agent-based model is then used to explore the effects of inclement weather and autonomous drivers on traffic to explore the suitability of using the agent-based approach to model traffic. The primary environment focused on is a signalized four-way intersection, with an extension to freeways for autonomous vehicle simulation. The model is used to demonstrate how optimizing green light intervals at intersections based on current weather conditions can help to partially restore traffic throughput to normal condition levels. Results from simulations with autonomous vehicles demonstrate that traffic flow steadily increases as these vehicles enter the driving population. In the case of signalized intersections this improvement increases in inclement weather, but increases are flat across different weather conditions for freeways.