Download or read book Developing Crash Modification Factors for Adaptive Signal Control Technologies written by Raul Avelar and published by . This book was released on 2020 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to perform rigorous safety effectiveness evaluations of adaptive signal control technologies (ASCTs) used on urban corridors. To accomplish the goal of this study, the research team compiled safety data from Florida, Texas, and Virginia. Results from Florida and Texas did not offer statistical evidence of a change in safety derived from implementing ASCTs, except for a statistically large and significant reduction in rear end crashes (0.560 crash modification factor (CMF)). Conversely, the results from Virginia produced evidence of significant reductions in total crashes (a 13.3-percent reduction, or 0.867 CMF, at the 10-percent significance level), fatal and severe crashes (a 35.8-percent reduction, or 0.642 CMF, at the 5-percent significance level), and angle crashes (39.6-percent reduction, or 0.604 CMF, at the 5-percent significance level). The research team also conducted an economic evaluation that considered two scenarios: one in which the safety benefit estimated from the Virginia analysis is realized and one in which no measurable safety effect is realized (the worst-case outcome observed in this study), but operational benefits accrue after ASCT installation. When assuming a 13.3-percent reduction in total crashes, the benefit—cost (B/C) ratio was estimated as 65.56. When assuming no safety benefit derived from ASCT installations, the B/C ratio estimate reduced to 25.46. Data were analyzed using multiple estimation methods, including empirical Bayes, full Bayes, and interrupted time series with generalized estimating equations.

Download or read book Developing Crash Modification Factors for Adaptive Signal Control Technologies written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluating the Mobility and Safety Benefits of Adaptive Signal Control Technology ASCT written by John Herman Kodi and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Adaptive Signal Control Technology (ASCT) is a traffic management strategy that optimizes signal timing based on real-time traffic demand. This thesis proposes a comprehensive methodology of quantifying the mobility and safety benefits of the ASCT deployed in the state of Florida. A Bayesian switch-point regression model was proposed to evaluate the mobility benefits of ASCT. The analysis was based on a 3.3-mile corridor along Mayport Road from Atlantic Boulevard to Wonderwood Drive in Jacksonville, Florida. The proposed analysis was used to estimate the possible dates that separate the two operating characteristics, i.e., with and without ASCT. Also, the posterior estimated distributions were used for the Bayesian hypothesis test to investigate if there is a significant difference in the operating characteristics for two scenarios - with and without ASCT. The results revealed that ASCT increases travel speeds by 4% in typical days of the week (Tuesday, Wednesday and Thursday) in the northbound direction. However, the implementation of ASCT did not yield a significant increase in travel speed in the southbound direction. In addition, ASCT exhibited more benefits in AM peak in the northbound direction indicating a 7% increase in travel speeds. A Bayesian hypothesis test revealed that there is a significant difference in the operating characteristics between scenarios with and without ASCT. Moreover, an observational before-after Empirical Bayes (EB) with a comparison-group approach was adopted to develop the Crash Modification Factors (CMFs) for certain crash types (total and rear-end crashes) and crash severity levels (fatalities and injury crashes). The CMFs developed were used to quantify the safety benefits of the ASCT. The analysis was based on 42 treatment intersections with ASCT and their corresponding 47 comparison intersections without ASCT. Florida-specific Safety Performance Functions (SPFs) for total and rear-end crashes and for fatal plus injury crashes were also developed. The deployment of ASCT was found to reduce total crashes and rear-end crashes by 5.2% (CMF = 0.948) and 10.6% (CMF = 0.894), respectively. On the other hand, fatal plus injury crashes and PDO crashes were reduced by 6.1% (CMF = 0.939) and 5.4% (CMF = 0.946), respectively, after the ASCT deployment. The CMFs for total crashes and rear-end crashes, and for fatal plus injury crashes and PDO crashes were found to be statistically significant at 95% confidence level. These findings provide researchers and practitioners with an effective means for quantifying the mobility and safety benefits of ASCT, economic appraisal of the ASCT as well as a key consideration to transportation agencies for future ASCT deployment in the state.

Download or read book Accident Modification Factors for Traffic Engineering and ITS Improvements written by David L. Harkey and published by . This book was released on 2008 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB¿s National Cooperative Highway Research Program (NCHRP) Report 617: Accident Modification Factors for Traffic Engineering and ITS Improvements explores the development of accident modification factors (AMFs) for traffic engineering and intelligent transportation system improvements. AMFs, also known as crash reduction factors, are designed to provide a simple and quick way of estimating the safety impacts of various types of engineering improvements, encompassing the areas of signing, alignment, channelization, and other traffic engineering solutions.

Download or read book Developing Crash Modification Factors for Variable Speed written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Guide to Developing Quality Crash Modification Factors written by Frank Gross and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developing crash modification factors for high friction surface treatments written by David K. Merritt and published by . This book was released on 2020 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developing crash modification factors for high friction surface treatments written by David K. Merritt and published by . This book was released on 2020 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developing Crash Modification Factors for Operational Parameters on Urban Freeways written by Eugene Vida Maina and published by . This book was released on 2013 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies have shown that, roadway safety has become an intensively investigated topic with the objective of improved understanding of the factors that cause crashes to occur. However, it has been shown that as traffic volumes continue to increase across the United States, 52% of drivers feel less safe on the roads today more than they did five years ago and that the American public feels that traffic safety is a serious problem that needs both the government and media to pay more attention to this issue. In response to these public and driver grievances, State and National transportation agencies have been and continue to pursue and understand the causes and solutions that would significantly reduce roadway crash frequencies. At national level, through various and rigorous studies, the American Association of State Highway and Transportation Officials, AASHTO has published the Highway Safety Manual to quantify safety using predictive models and CMFs. Various efforts have been attempted at state level too, for example, Texas DOT has developed an Interim Roadway Safety Design Workbook that describes the relationship between various roadway elements and each element influences roadway safety. In an effort to contribute towards understanding and resolving the factors that influence crash frequencies on roadways, through a thorough literature search. This study realizes that although there has been vast research in this area, no study has explicitly explained why there is variation in crash frequencies on roadways segments with similar physical/geometric features and annual average daily traffic (AADT). Studies suggest that these variations are due to volume changes throughout the day, an effect literature shows that can only be addressed by hourly volumes and not AADT. Driven by these literature conclusions, this dissertation develops crash modification factors (CMFs) for urban freeways by considering level of service (LOS) deterioration due to change in hourly traffic volumes. Here, this study investigates LOS when it deteriorated from A to B, B to C, C to D, D to E and E to F using hourly volume and hourly crash data collected on urban freeway segments, specifically routes US 1, NJ 3 and NJ 21 in the State of New Jersey. Data were collected on 14 miles of urban freeway segments and 1344 hours of traffic volume count and crash data were analyzed for a period of four years, 2008, 2009, 2010, and 2011. Results from this investigation, shows that operational elements have some influence on urban freeway safety. This dissertation shows that as LOS deteriorated from A to B, B to C, C to D, D to E and E to F, the estimated CMFs were 0.673, 1.110, 0.865, 1.452, and 0.370 respectively. These findings concur with those referred to in this dissertation’s literature review findings, which showed that by adding capacity, that is, by reducing congestion initially results in safety improvement that diminishes as congestion increases.

Download or read book Crash Modification Factors in Practice written by and published by . This book was released on 2013 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidelines for the Development and Application of Crash Modification Factors written by Daniel Lance Carter and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crash modification factors (CMF) provide transportation professionals with the kind of quantitative information they need to make decisions on where best to invest limited safety funds.

Download or read book Transportation Cyber Physical Systems written by Lipika Deka and published by Elsevier. This book was released on 2018-07-30 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transportation Cyber-Physical Systems provides current and future researchers, developers and practitioners with the latest thinking on the emerging interdisciplinary field of Transportation Cyber Physical Systems (TCPS). The book focuses on enhancing efficiency, reducing environmental stress, and meeting societal demands across the continually growing air, water and land transportation needs of both people and goods. Users will find a valuable resource that helps accelerate the research and development of transportation and mobility CPS-driven innovation for the security, reliability and stability of society at-large. The book integrates ideas from Transport and CPS experts and visionaries, consolidating the latest thinking on the topic. As cars, traffic lights and the built environment are becoming connected and augmented with embedded intelligence, it is important to understand how smart ecosystems that encompass hardware, software, and physical components can help sense the changing state of the real world. Bridges the gap between the transportation, CPS and civil engineering communities Includes numerous examples of practical applications that show how diverse technologies and topics are integrated in practice Examines timely, state-of-the-art topics, such as big data analytics, privacy, cybersecurity and smart cities Shows how TCPS can be developed and deployed, along with its associated challenges Includes pedagogical aids, such as Illustrations of application scenarios, architecture details, tables describing available methods and tools, chapter objectives, and a glossary Contains international contributions from academia, government and industry

Download or read book Observational Before after Studies in Road Safety Estimating the Effect of Highway and Traffic Engineering Measures on Road Safety written by Ezra Hauer and published by . This book was released on 1997 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developing Crash Modification Factors for High Friction Surface Treatments written by David K. Merritt and published by . This book was released on 2020 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents results and observations from friction testing of high-friction surface treatments (HFSTs) as part of an FHWA research study, Developing Crash-Modification Factors for High-Friction Surface Treatments. This larger study provides high-quality crash-modification factors and benefit–cost ratios for HFST with calcined bauxite aggregate and recommends materials and specifications for applying HFST to effectively reduce roadway departure crashes. Friction testing was performed to document the friction of the HFST and underlying pavement. For a number of sites, friction testing was performed on the existing pavement surface before HFST installation and on the HFST after installation. In some cases, testing of the pavement leading up to and away from existing HFST sites was used to estimate the friction of the underlying pavement for comparison to HFST friction. To evaluate friction change of HFST over time, friction testing was also performed on several older HFST installations where previous friction data had been collected. All friction testing was performed with a highway friction tester, a continuous fixed-slip measurement device that provides a continuous plot of friction reported in 0.30-meter (1-foot) increments through the section of pavement tested. The advantage of continuous friction measurement is that variations in friction (e.g., through a curve) can be documented. The friction data collected during this research and documented in this report were evaluated for friction change before and after HFST installation, friction change of the HFST and existing pavement over time, and friction change within a curve.

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 Guide for the Planning Design and Operation of Pedestrian Facilities written by and published by AASHTO. This book was released on 2004 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Traffic Signal Timing Manual written by U.s. Department of Transportation and published by CreateSpace. This book was released on 2015-02-20 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.