Download or read book Evaluation of the Safety and Mobility Impacts of a Proposed Speed Harmonization System written by Jonathan Kenneth Markt and published by . This book was released on 2011 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overuse of the Interstate and National Highway Systems has led many urban freeways to suffer from recurrent congestion and high crash rates. One method of ameliorating these problems is through the use of Active Traffic Management (ATM). Within ATM, the practice of speed harmonization is well suited to improving safety and reducing delay. In this study, speed harmonization is applied to a segment of Interstate Highway 35, just south of downtown Austin, Texas. First, the need for congestion and safety improvements will be established. Then, the framework of a speed harmonization system will be developed through a synthesis of speed harmonization best practice. Next, the speed harmonization framework will be evaluated for its impact on efficiency through the development of before and after micro-simulation models. Finally, the trajectory files generated from simulation will be analyzed using surrogate safety measures to assess the safety impact of the proposed speed harmonization system.

Download or read book Mobility and Safety Evaluation of Integrated Dynamic Merge and Speed Control Strategies in Work Zones written by Syed Muhammad Zaier Abbas Zaidi and published by . This book was released on 2010 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, there has been a considerable increase in the amount of construction work on the U.S. national highways. Most of the work undertaken is the reconstruction and rehabilitation of the existing transportation networks. Work zones in the United States are likely to increase in number, duration and length due to emphasis on repair and highway reconstruction as a significant portion of all federal-aid highway funds are now geared toward highway rehabilitation. The challenge of mobility is particularly acute in work zone areas as road repair and construction intensifies traffic issues and concentrates them in specific locations and at specific times. Due to the capacity drop, which is the result of lane closure in work zone area, congestion will occur with a high traffic demand. The congestion increases number and severity of traffic conflicts which raise the potential for accidents; furthermore traffic operational properties of roadway in work zone area become worse. Intelligent Transportation System (ITS) technologies have been developed and are being deployed to improve the safety and mobility of traffic in and around work zones. In several states in the US, the use of Dynamic Merge Controls also known as Dynamic Lane Merge (DLM) system has been initiated to enhance traffic safety and to improve traffic flow in work zone areas. The DLM usually takes two forms; dynamic early merge and dynamic late merge. The use of variable speed limit (VSL) systems at work zones is also one of those measures. VSL systems improve safety by helping the driver in determining the maximum speed that drivers should travel. Besides adding improvement to safety, they are also expected to improve mobility at the work zones. The main goal of this study is to evaluate the safety and operational effectiveness of the dynamic merge systems i.e. the dynamic early lane merge and dynamic late lane merge, in the presence of VSL system. More specifically, the VISSIM model is utilized to simulate a two-to-one lane configuration when one out of the two lanes in the work zone is closed for traffic. Six different scenarios were adopted to assess the effectiveness of these scenarios under different traffic demand volumes and different drivers' compliance rates to the messages displayed by the systems. These scenarios are; [bullet] Work Zone without VSL and without SDLMS or the current Motorist Awareness System (MAS) [bullet] Work Zone with VSL and without SDLMS [bullet] Work Zone with VSL and Early SDLMS [bullet] Work Zone with VSL and Late SDLMS [bullet] Work Zone with early SDLMS and without VSL [bullet] Work Zone with early SDLMS and without VSL An already calibrated and validated VISSIM model for Simplified Dynamic Lane Merge System (SDLMS) in accordance with the real life work zone was modified with a VSL through Vehicle Actuated Programming (VAP) code. Three different logics were coded each for VSL alone, early SDLMS+VSL and late SDLMS+VSL. All these logics were fine tuned with several test runs before finalizing it for the final simulation. It is found through the simulation of above mentioned scenarios that for low and medium volume levels (V0500, V1000 and V1500), there is no significant difference between the Maintenance of Traffic (MOT) plans for mean throughputs. However, for higher volume levels (V2000 and V2500), late SDLMS with and without VSL produced higher mean throughputs for all compliance rates and truck percentages except when the demand volume was 2,500 vph and compliance of 60%, where it produces the significantly lower mean throughputs. In terms of travel time through the work zone, results indicated that there is no significant difference between MOT types for demand levels of V0500 and V1000 when compliance is 40% or less but for compliance of 60% and more, only demand volume level that is not significantly different from other MOT types is V0500. This study revealed that VSL increases travel time through the work zone. This might be due to non-compliant vehicles that follow the compliant vehicle ahead unless they find a sufficient gap in adjacent lane to pass the compliant vehicle. It is also found out that VSL makes the system safer at higher volumes (2,000 vph and 2,500 vph). This was observed through safety surrogate measures selected for this study. Another outcome of this study is that the addition of VSL to the dynamic merge systems helps in improving the overall safety of the system by lowering speed variances and deceleration means of the vehicles travelling through the work zone. The passage of traffic through the work zone is made safer when a speed control is integrated to a dynamic merge system. It can be inferred from the simulation results that integrated SDLMS and VSL systems have better performance in terms of traffic mobility and safety than existing individual controls and also show that the integrated SDLMS and VSL system has more potential than each individual systems.

Download or read book Evaluation of Safety and Mobility Benefits of Connected and Automated Vehicles by Considering V2X Technologies written by Md Hasibur Rahman and published by . This book was released on 2020 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Furthermore, the study considered the performance of different communication system along with the traffic condition by utilizing Dedicated Short-Range Communications (DSRC or IEEE 802.11p) and wireless access (IEEE 1609 protocol) for the application of vehicle ad-hoc network (VANET). To this end, the study evaluated the safety effectiveness of different communication protocols under the CAV environment. Aimsun Next and SUMO & OMNET++ based Veins simulator were used as the simulation platform. Different car-following models, signal control algorithm, and communication systems were coded by using the application programming interface (API) and C++ language. For the traffic efficiency, the study utilized travel time and travel time rate (TTR) while for the safety evaluation, different surrogate safety measures; speed, and crash-risk models were used. Also, several statistical tests (e.g., t-test, ANOVA) and modeling techniques (e.g., generalized estimating equation, logistic regression, etc.) were developed to analyze both safety and mobility. The results of this study implied that CAV could improve both safety and efficiency at the network level with different MPRs. Also, CAV is more efficient compared to the only AV in terms of both traffic safety and mobility. Different communication protocols have a significant effect on traffic safety under the CAV environment. Finally, the results of this study provide insight to transportation planners and the decision makers about the benefits of CAV at the network level, different CAV technologies, and the performance of different communication systems under the CAV environment.

Download or read book Active Safety and the Mobility Industry written by Delphi Corp. and published by SAE International. This book was released on 2011-04-11 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety is a key element in new vehicle design and active safety, together with driver distraction prevention, has become one of the most talked about issues in the mobility industry. This book features 20 SAE technical papers, originally published in 2009 and 2010, which showcase how the mobility industry is considering all aspects of safety in designing and producing safer vehicles. These papers were selected by SAE International's 2010 President Dr. Andrew Brown Jr., Executive Director and Chief Technologist for Delphi Corporation. The contents of this book explore a variety of safety issues in the areas of market and consumer preferences; driver assistance and modeling; active safety system, crash sensing and sensor fusion; communications; and road safety. The publication also includes a number of articles authored by renowned experts in the field of active safety. This book is the second in the trilogy from SAE on "Safe, Green and Connected" vehicles in the mobility industry edited by Dr. Andrew Brown, Jr. The other two books in this trilogy are: Green Technologies and the Mobility Industry Connectivity and the Mobility Industry Buy a Combination of Books and Save! This trilogy can be purchased in a combination of two books as follows: Green Technologies and Active Safety in the Mobility Industry Green Technologies and Connectivity in the Mobility Industry Active Safety and Connectivity in the Mobility Industry Buy the Entire 3 Book Set and Save the Most! Green, Safe & Connected: The Future of Mobility

Download or read book Assessment of Operational and Safety Impacts of Various Traffic Control Devices written by Megat Usamah Bin Megat Johari and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatal crashes have been increasing, both in Michigan and across the United States, despite continuing improvements in roadway design, vehicle safety, and other areas. Various factors may have contributed to this trend, including increased in-vehicle distractions, higher speed limits, legalization of marijuana, and other factors. Studies have suggested that driver error is a critical reason associated with more than 90 percent of all traffic crashes. Driver behavior can be improved by several engineering strategies, such as the use of better and more efficient traffic control devices, such as signs, signals, and pavement markings. To that end, this research assesses the operational and safety impacts of a series of traffic control devices.The use of dynamic message signs (DMS) as a medium to display safety messages to drivers has become popular among transportation agencies. Despite their widespread use, evaluations as to the resultant impacts on traffic crashes have been very limited. This study addresses this gap in the extant literature and assesses the relationship between traffic crashes and the frequency with which various types of safety messages are displayed. A series of count models are estimated to examine total, speeding-related, and nighttime crashes based upon historical messaging data while controlling for other site-specific factors. Ultimately the results provide important insights regarding messaging strategies for transportation agencies. This research also evaluates driver response to advisory speed signs. Posted speed limit signs are used to inform drivers of the legal maximum allowable speed. In contrast, advisory speed signs provide recommendations to drivers as to safe travel speeds at specific roadway locations. Various studies have investigated the safety impacts of speed limit changes, particularly on high-speed rural highways. One area of particular concern on such roadways is the approach to exit ramps that require substantive speed reductions, such as loop ramps. To date, there has been limited research examining the safety impact of the differential between the mainline speed limit and the lower exit ramp advisory speeds. This study addresses this gap through the estimation of a series of safety performance functions. The findings from this study show the safety of these locations is related to speed differential, as well as other factors such as the length of the upstream deceleration lane. These factors should be considered when considering speed limit policy impacts in the vicinity of full and partial cloverleaf interchanges.Lastly, this study assesses the use of dynamic speed feedback sign (DSFS) as a means to reduce vehicle speeds in speed transition zones, where speeds are reduced as drivers enter rural communities. DSFS have been evaluated in several settings, including high-speed exit ramps and horizontal curves. However, research is limited as to the effectiveness of this sign for other purposes, such as these high-speed transition areas. This is particularly important as the limits on some of these roadways have recently been increased, making speed control a particular concern. This study addresses this gap through a before-and-after evaluation of DSFS at five different sites in northern Michigan. A series of speed models were estimated, which provide insights on the effectiveness of DSFS.

Download or read book Symposium on Traffic Safety Effectiveness impact Evaluation Projects Final Report written by Thomas W. Planek and published by . This book was released on 1981 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Economic Evaluation of the Impact of Safe Speeds written by W. J. Frith and published by . This book was released on 2012 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The safe system approach to road safety implies the goal of removing fatal and serious injury crashes from the road network. This review addresses: 1. alternative ways of classifying roads in relation to speed, across the road network, compatible with the safe system approach; 2. how speed relates to crashes, fuel consumption and emissions; 3. the values currently placed on the costs of serious and fatal crashes, travel time and fuel savings in the developed world; 4. how on a macroscopic scale these values can be translated into greenhouse gas emissions savings; 5. how these values relate in the cost-benefit analysis context under a safe system approach to speed. Well attested relationships were found between speed and crashes. Safe system road types related to the maximum speeds above which serious or fatal injury would occur in various types of crashes. Internationally, valuation of crashes is mainly based on willingness-to-pay criteria. The values placed on time are constant unit values which are a less conservative approach as there are strong grounds for sometimes discounting the values of small time periods. Macroscopic fuel savings can be linked to greenhouse gas emissions with costs expressed as unit values per kilogram of emissions.

Download or read book Speed Variation and Safety in Work Zones written by John Anthony Gambatese and published by . This book was released on 2021 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: In addition to lower speeds, the difference between vehicle speed and the average speed on the roadway has been identified as a factor in roadway crashes. For work zones, the potential for such speed variation from the average speed is magnified. The safety associated with speed variation in work zones affects both motorists driving through the work zone and the workers in the work zone. The overall goal of this research is to develop additional knowledge and practices that can be used to improve driver and worker safety in work zones and, as a result, mobility through work zones. The research focuses on high-speed roadways (e.g., highways and freeways) and typical mobile construction and maintenance operations that occur on such roadways (e.g., paving and re-striping). The research presented in this report involved a review of the archival literature germane to the topic of speed variation (with and without a work zone), the analysis results of speed variation and crash occurrence, and the impacts of selected traffic control interventions on speed variation in work zones in Oregon. The PCMS unit showing alternating messages "MAINTAIN CONSTANT SPEED" and "THRU WORK ZONE" in two phases and placed at the advance warning area was found to effectively reduce speed variation in the work zone. Based on the findings, the researchers recommend use of PCMS units that display custom messages to maintain constant speed for work zone operations on high-speed roadways.

Download or read book Safety Data Analysis and Evaluation written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB?s Transportation Research Record: Journal of the Transportation Research Board, No. 2514, explores 19 papers related to safety data, analysis, and evaluation in the transportation sector, including: Exploring Driver Error at Intersections: Key Contributors and Solutions; Level of Service of Safety Revisited; Longitudinal Analysis of Rural Interstate Fatalities in Relation to Speed Limit Policies; Predicting Crashes on Expressway Ramps with Real-Time Traffic and Weather Data; Multilevel Logistic Regression Modeling for Crash Mapping in Metropolitan Areas; Simulated Traffic Conflicts: Do They Accurately Represent Field-Measured Conflicts?; Assessing Safety Improvements to Pedestrian Crossings Using Automated Conflict Analysis; Understanding Factors Affecting Frequency of Traffic Conflicts Between Electric Bicycles and Motorized Vehicles at Signalized Intersections; Comparative Analysis of Injury Severity Resulting from Pedestrian?Motor Vehicle and Bicycle?Motor Vehicle Crashes on Roadways in Alabama; Validation of Crash Modification Factors Derived from Cross-Sectional Studies with Regression Models; Fault Determination for Crashes in Vermont: Implications of Distance from Home; Crash Patterns at Signalized Intersections; Analyses of Multiyear Statewide Secondary Crash Data and Automatic Crash Report Reviewing; Assessment of Pedestrian Risk at Crossings with Kinematic?Probabilistic Model; Predicting Driver Injury Severity in Single-Vehicle and Two-Vehicle Crashes with Boosted Regression Trees; Effects of Geodemographic Profiles of Drivers on Their Injury Severity from Traffic Crashes Using Multilevel Mixed-Effects Ordered Logit Model; Copula-Based Joint Model of Injury Severity and Vehicle Damage in Two-Vehicle Crashes; Identifying Optimal High-Risk Driver Segments for Safety Messaging: Geodemographic Modeling Approach; Evaluation of Signalized-Intersection Crash Screening Methods Based on Distance from Intersection."--Publisher's description.

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 The Safety of Intelligent Driver Support Systems written by Ralf Risser and published by CRC Press. This book was released on 2019-07-15 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of new technologies of information and communication will, in the coming years, transform deeply their uses and practices in transport. The current developments in the field of road telematics and driver assistance systems offer a real opportunity to aid mobility and road safety. However, they also raise numerous questions about their effectiveness, possible positive and negative modifications of behaviour or attitudes and about their acceptability by drivers. Problems related to the design and evaluation of intelligent driver support systems (IDSSs) and social perspectives related to their introduction on a large scale may only be fully addressed from a multi-disciplinary point of view. People from different backgrounds, from both engineering and social sciences, should be involved in this development. This book provides such knowledge from both a human and social factors background. The Safety of Intelligent Driver Support Systems serves the training of professionals working within the transport area so that they can use this knowledge in their work. It will be of direct interest to transportation and traffic professionals, engineers, system designers, researchers and specialists working in automotive and related industries, departments of transport, and communication and public bodies related to transport in the automotive industry, public authorities, etc. Also students at Masters and PhD level, performing studies in the road transportation area, will find in this book a rich source of knowledge. Teachers and trainers, both in professional training and academic education, may use the book as a basis for giving a course on the topic addressed.

Download or read book Road Vehicle Automation 3 written by Gereon Meyer and published by Springer. This book was released on 2016-07-01 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited book comprises papers about the impacts, benefits and challenges of connected and automated cars. It is the third volume of the LNMOB series dealing with Road Vehicle Automation. The book comprises contributions from researchers, industry practitioners and policy makers, covering perspectives from the U.S., Europe and Japan. It is based on the Automated Vehicles Symposium 2015 which was jointly organized by the Association of Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Ann Arbor, Michigan, in July 2015. The topical spectrum includes, but is not limited to, public sector activities, human factors, ethical and business aspects, energy and technological perspectives, vehicle systems and transportation infrastructure. This book is an indispensable source of information for academic researchers, industrial engineers and policy makers interested in the topic of road vehicle automation.

Download or read book Autonomous Vehicles and Future Mobility written by Pierluigi Coppola and published by Elsevier. This book was released on 2019-06-11 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous Vehicles and Future Mobility presents novel methods for examining the long-term effects on individuals, society, and on the environment for a wide range of forthcoming transport scenarios, such as self-driving vehicles, workplace mobility plans, demand responsive transport analysis, mobility as a service, multi-source transport data provision, and door-to-door mobility. With the development and realization of new mobility options comes change in long-term travel behavior and transport policy. This book addresses these impacts, considering such key areas as the attitude of users towards new services, the consequences of introducing new mobility forms, the impacts of changing work related trips, and more. By examining and contextualizing innovative transport solutions in this rapidly evolving field, the book provides insights into the current implementation of these potentially sustainable solutions. It will serve as a resource of general guidelines and best practices for researchers, professionals and policymakers.

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 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 Towards Zero Ambitious Road Safety Targets and the Safe System Approach written by International Transport Forum and published by OECD Publishing. This book was released on 2008-09-23 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report takes stock of recent developments and initiatives to meet increasingly ambitious road safety targets, and constitutes a major international review of progress in developing Safe System approaches, now adopted in a small number of countries.