Download or read book Using Connected Vehicles in Variable Speed Limit Systems written by Ellen F. Grumert and published by Linköping University Electronic Press. This book was released on 2018-04-10 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Motorway traffic management systems are useful for improving the traffic conditions on urban motorways. One of the most common motorway traffic management systems are variable speed limit systems. These systems adapt the speed limits based on the prevailing traffic conditions measured by roadside detectors and recommended or compulsory speed limits are shown on variable message signs installed on gantries over the road.Thesystems consist of three parts; the control algorithm used to determine which speed limit to be displayed, a method for estimating the traffic conditions to be used as input for the control algorithm and the infrastructure for application of the variable speed limits. The goal of the systems is often to increase safety or efficiency. Recent development in the field of connected vehicles have opened up for a new type of data source, as the status of a connected vehicle and its surroundings can be communicated at arbitrary locations. Hence, by the use of connected vehicles in variable speed limit systems there is a potential of reducing the amount of roadside equipment. It is even possible to control the connected vehicles towards the current speed limit without the use of variable message signs. This allows for the application of variable speed limits at arbitrary locations. The aim of this thesis is to examine how connected vehicles can be used to improve the efficiency of variable speed limit systems. The thesis contribute with new and improved methods using connected vehicles in all three parts of a variable speed limit system. The suggested methods are evaluated by microscopic traffic simulation. The overall conclusion is that the use of connected vehicles in variable speed limit systems can contribute to improvements in traffic efficiency compared to existing systems. The six papers included in the thesis can be summarized as follows. First, it is shown that traditional variable speed limit systems can be effective for improving the traffic conditions on the motorway and the results can be comparable to more costly alterations by reconstruction of the infrastructure to increase the capacity. Next, the usefulness of connected vehicles for application and control of the speed limits in an existing variable speed limit system is investigated. It is concluded that the design of the control algorithm and the accuracy of the estimated traffic conditions have a great effect on the final outcome of the system. The design of the control algorithm is then examined by evaluation of a number of control algorithms with respect to safety, efficiency and environmental impacts. The main benefits and drawbacks of the algorithms are highlighted and desirable characteristics to include when designing a control algorithm are identified. In two studies, methods making use of connected vehicles for estimating the traffic conditions are proposed. The results show that connected vehicles are useful for improving the accuracy of the estimated traffic conditions through the inclusion of more detailed information and information at locations where detector measurements are not available. Finally, a variable speed limit system is proposed in which connected vehicles play a central role in the estimation of the traffic conditions, as well as in the control algorithm and for application of the speed limit. The system is shown to be useful for improving traffic efficiency during an incident at an arbitrary location along the controlled road.
Download or read book Model Predictive Control for Integrating Traffic Control Measures written by András Hegyi and published by . This book was released on 2003 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identifying Effects and Applications of Fixed and Variable Speed Limits written by Michelle Mekker and published by . This book was released on 2017-04-30 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Indiana, distracted driving and unexpected queues have led to an increase in the amount of back-of-queue crashes, particularly on approach to work zones. This report presents new strategies for the assessment of both transportation safety and traffic operations using crowd-sourced probe vehicle data and a speed laser vehicle re-identification scheme. This report concludes by recommending strategies for the placement of variable speed limits (VSL) adjacent to work zones and suggestions for future research.
Download or read book Speed Management written by European Conference of Ministers of Transport and published by OECD Publishing. This book was released on 2006 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Report addresses the key issues surrounding traffic speed management and highlights the improvements in policy and operations needed to reduce the extent of speeding.
Download or read book Managing Speed written by and published by Transportation Research Board. This book was released on 1998 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB Special Report 254 - Managing Speed: Review of Current Practices for Setting and Enforcing Speed Limits reviews practices for setting and enforcing speed limits on all types of roads and provides guidance to state and local governments on appropriate methods of setting speed limits and related enforcement strategies. Following an executive summary, the report is presented in six chapters and five appendices.
Download or read book Control Logic for the Operation of Rural Variable Speed Limits Subject to Severe Winter Conditions written by Vijay Kumar Sabawat Krishna and published by . This book was released on 2013 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Variable Speed Limit (VSL) systems are an innovative way of managing traffic using Intelligent Transportation Systems (ITS). Unlike the traditional static speed limit signs, VSLs are speed limit signs with a capability of changing regulatory speed limits according to changing real time weather and traffic conditions. VSLs are primarily used to reduce traffic congestion and improve safety along roadways. Wyoming weather is highly variable and often severe, in the absence of recommended speed limits for such conditions drivers select their own safe driving speed leading to high variance among vehicles. This high speed variance, results in high crash rates and frequent road closures. Currently Wyoming Department of Transportation (WYDOT) using an interim manual protocol to deploy speed limits on VSL corridors. A new automated self-learning methodology for deploying VSL is described in this dissertation. As a first step in this project, weather variables that have a significant effect on vehicle speeds during bad weather conditions were identified using a robust regression statistical procedure. Second, an automated control strategy was designed that uses real time weather and observed speed variables. Third, a statistical model called decision trees was used in control strategy to enhance the performance of the automated control strategy. Fourth, a self-learning component is added to the control strategy to address concerns about the high variability of different storm events in this region. The proposed automated self-learning algorithm was tested on previous storm event datasets and results from the simulation indicate that the new system is more efficient than the current manual protocol of deploying speed limits. Finally, the transferability of the proposed control strategy was evaluated by applying the self-learning control strategy that was developed based on the storm data available at the Elk Mountain corridor to the storm data available at Laramie-Cheyenne corridor.
Download or read book Autonomous Driving written by Markus Maurer and published by Springer. This book was released on 2016-05-21 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book takes a look at fully automated, autonomous vehicles and discusses many open questions: How can autonomous vehicles be integrated into the current transportation system with diverse users and human drivers? Where do automated vehicles fall under current legal frameworks? What risks are associated with automation and how will society respond to these risks? How will the marketplace react to automated vehicles and what changes may be necessary for companies? Experts from Germany and the United States define key societal, engineering, and mobility issues related to the automation of vehicles. They discuss the decisions programmers of automated vehicles must make to enable vehicles to perceive their environment, interact with other road users, and choose actions that may have ethical consequences. The authors further identify expectations and concerns that will form the basis for individual and societal acceptance of autonomous driving. While the safety benefits of such vehicles are tremendous, the authors demonstrate that these benefits will only be achieved if vehicles have an appropriate safety concept at the heart of their design. Realizing the potential of automated vehicles to reorganize traffic and transform mobility of people and goods requires similar care in the design of vehicles and networks. By covering all of these topics, the book aims to provide a current, comprehensive, and scientifically sound treatment of the emerging field of “autonomous driving".
Download or read book Green Transportation and Low Carbon Mobility Safety written by Wuhong Wang and published by Springer Nature. This book was released on 2022-10-27 with total page 719 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings gather selected papers from the 12th International Conference on Green Intelligent Transportation Systems and Safety, held in Beijing, China on November 17-19, 2021. The book contains cutting-edge research on Green Intelligent Mobility Systems, with the goal of achieving "green, intelligent, and safe transportation systems" as the guiding slogan. The contributions offered here can aid in the advancement of green mobility and intelligent transportation technology by increasing interconnectivity, resource sharing, flexibility, and efficiency. Researchers and engineers in the areas of Transportation Technology and Traffic Engineering, Automotive and Mechanical Engineering, Industrial and System Engineering, and Electrical Engineering will all benefit from the book's scope.
Download or read book Impacts of Freeway Speed Limit on Safety and Operation Speed of Adjacent Arterial Roads written by Fadi Abdallah Alhomaidat and published by . This book was released on 2019 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Urban arterials carry the most traffic on urban road networks and experience the highest percentage of crashes in urban areas. Safety on the lower speed urban arterials that are adjacent to a higher speed freeway may be impacted by speed spillover or adaptation. In this context, speed spillover is defined as the tendency of drivers to speed on the lower speed facility after exiting the higher speed facility. The objective of this research is to investigate drivers' speed choices and the relationship between speed and crashes on urban arterials adjacent to freeways. The study also examines potential countermeasures for speeding behavior in the area under the speed spillover effect. To determine the effect of freeway speed limits on speed spillover, analysis was performed using two types of speed data: (1) point (i.e., spot speed) and (2) trajectory (i.e., continuous trip time series). While spot speed data were collected using a radar technology, the trajectory data were gathered from around 2,700 vehicles equipped with connected vehicle technologies and acquired from Intelligent Transportation System Research Data Exchange - Safety Pilot Model Deployment (SPMD) roadside equipment. Comparison of speed differences between motorists who exited the freeway and those who were already driving on the arterial road was performed. Results showed that the mean speed and the 85th percentile speed of vehicles exiting from the 70 mph freeway are significantly higher when compared to the vehicles that were already driving on the arterial road. The effect of raising freeway speed limits to 70 mph on the frequency of speed-related crashes on urban arterial roads adjacent to freeways (i.e., spillover effects) was investigated. Crash data were collected from Michigan on 1,393 road segments of urban arterials before and after speed limits were altered. Before-and-after data was collected simultaneously on 1,470 comparison segments of urban arterial where speed limits did not change to control for the regression-to-the-mean bias. The mixed effects negative binomial (MENB) regression model was developed to analyze crash frequency. The results indicate that raising speed limits of freeways by as much as five miles per hour had a likelihood of increasing crash frequency on adjacent arterial roads by as much as 13.9 percent. This increment in crashes observed on arterial roads involved more different crash types comparing to those that occurred on freeway. There exist more potential motorist-to-motorist conflicts as well as motorist-to-other road users (e.g., pedestrians and bicyclists) on arterial roads than on freeways. Therefore, the potential for a speeding vehicle to collide with another vehicle or other road user is higher on urban arterials. To investigate if the safety impact of speed spillover changes with the distance from the freeway, influence areas (0-1 mile, 1-2 mile, and 2-3 mile) were used. Speed-related crashes were impacted more on the 0-1 mile and the 1-2 ranges by 41.1 percent and 17.5 percent, respectively, compared to the 2-3 mile range. The study finds that the influence of freeway speed on drivers' speeding behavior on adjacent urban arterials fades away as the distance from the freeway increases. To mitigate speed spillover, a driving simulator study was used to investigate potential countermeasures for speeding behavior. The study observed the behavior of 56 participants who drove a 5300 meters section of freeway, then exited to a two-mile urban arterial. The driving simulator results were validated using field data collected from trajectory speed data. The impact of Crash Fact Sign (CFS), a message that provides information about the number of crashes/fatalities that occurred on that particular road, and Warning Sign (WS) on areas under the speed spillover influence were studied. Each participant was asked to drive under a base scenario (without any countermeasure) and four test scenarios, namely(1) an additional speed limit sign (SLS-2); (2) Warning Sign (WS); (3) Crash Fact Sign (CFS); and (4) Crash Fact Sign With additional Speed Limit Sign (CFS&SLS-2). The study finds CFS&SLS-2 to be the most effective countermeasure because it produces significant speed reductions in the area under speed spillover effect. Furthermore, the effect of a traffic signal on speed spillover behavior was investigated. Speed spillover effect existed for longer distance when drivers did not stop at the signalized intersection compared to when drivers stopped. This study provides researchers, policymakers, law enforcement officials, and engineers with a better understanding of the effects of speed spillover on adjacent roads when determining whether to increase the speed limit on freeways. The study suggests that urban arterial segments adjacent to high speed freeways need more attention in terms of speeding countermeasures. It also recommends potential effective countermeasures for speeding.
Download or read book Roundabouts written by Lee August Rodegerdts and published by Transportation Research Board. This book was released on 2010 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 672: Roundabouts: An Informational Guide - Second Edition explores the planning, design, construction, maintenance, and operation of roundabouts. The report also addresses issues that may be useful in helping to explain the trade-offs associated with roundabouts. This report updates the U.S. Federal Highway Administration's Roundabouts: An Informational Guide, based on experience gained in the United States since that guide was published in 2000.
Download or read book Strong Towns written by Charles L. Marohn, Jr. and published by John Wiley & Sons. This book was released on 2019-10-01 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new way forward for sustainable quality of life in cities of all sizes Strong Towns: A Bottom-Up Revolution to Build American Prosperity is a book of forward-thinking ideas that breaks with modern wisdom to present a new vision of urban development in the United States. Presenting the foundational ideas of the Strong Towns movement he co-founded, Charles Marohn explains why cities of all sizes continue to struggle to meet their basic needs, and reveals the new paradigm that can solve this longstanding problem. Inside, you’ll learn why inducing growth and development has been the conventional response to urban financial struggles—and why it just doesn’t work. New development and high-risk investing don’t generate enough wealth to support itself, and cities continue to struggle. Read this book to find out how cities large and small can focus on bottom-up investments to minimize risk and maximize their ability to strengthen the community financially and improve citizens’ quality of life. Develop in-depth knowledge of the underlying logic behind the “traditional” search for never-ending urban growth Learn practical solutions for ameliorating financial struggles through low-risk investment and a grassroots focus Gain insights and tools that can stop the vicious cycle of budget shortfalls and unexpected downturns Become a part of the Strong Towns revolution by shifting the focus away from top-down growth toward rebuilding American prosperity Strong Towns acknowledges that there is a problem with the American approach to growth and shows community leaders a new way forward. The Strong Towns response is a revolution in how we assemble the places we live.
Download or read book Road Vehicle Automation 5 written by Gereon Meyer and published by Springer. This book was released on 2018-06-25 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the fifth volume of a sub series on Road Vehicle Automation published within the Lecture Notes in Mobility. Like in previous editions, scholars, engineers and analysts from all around the world have contributed chapters covering human factors, ethical, legal, energy and technology aspects related to automated vehicles, as well as transportation infrastructure and public planning. The book is based on the Automated Vehicles Symposium which was hosted by the Transportation Research Board (TRB) and the Association for Unmanned Vehicle Systems International (AUVSI) in San Francisco, California (USA) in July 2017.
Download or read book Literature Review on Vehicle Travel Speeds and Pedestrian Injuries written by W. A. Leaf and published by . This book was released on 1999 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Smart Transport for Cities and Nations written by Christian Claudel and published by . This book was released on 2018-06-30 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Autonomous Vehicle Technology written by James M. Anderson and published by Rand Corporation. This book was released on 2014-01-10 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The automotive industry appears close to substantial change engendered by “self-driving” technologies. This technology offers the possibility of significant benefits to social welfare—saving lives; reducing crashes, congestion, fuel consumption, and pollution; increasing mobility for the disabled; and ultimately improving land use. This report is intended as a guide for state and federal policymakers on the many issues that this technology raises.
Download or read book Evaluating Alternative Operations Strategies to Improve Travel Time Reliability written by National Academies of Sciences, Engineering, and Medicine (U.S.) and published by Transportation Research Board. This book was released on 2022-03-29 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report from the second Strategic Highway Research Program (SHRP 2), which is administered by the Transportation Research Board of the National Academies, sets out requirements for travel time reliability within a performance-based planning process. The research includes an effort to determine the economic value of improvements in travel time reliability by applying options theory from the financial sector. The report includes two succinct tables that describe requirements for person and freight trips for reliable transport, as well as a forecast of the year 2030 under alternative assumptions that may influence travel time reliability.
Download or read book Revitalizing a Nation written by Clifford Winston and published by Brookings Institution Press. This book was released on 2023-12-20 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: An efficient transportation system reduces the cost of distance by moving people and goods from their origins to their destinations as cheaply, quickly, and safely as possible. By enabling individuals and firms to be more productive, transportation provides the foundation for the development and growth of industries and an entire economy. Clifford Winston, Jia Yan, and Associates argue that competition and innovation are the key drivers of an efficient transportation system. The authors provide new evidence that transportation deregulation and privatization that spur additional competition among carriers and infrastructure providers, as well as new innovations that create autonomous transportation services, have the potential to rid the US transportation system of its major inefficiencies and revitalize the nation.
