A Planning-level Methodology for Identifying High-crash Sections of Virginia's Primary System - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook A Planning-level Methodology for Identifying High-crash Sections of Virginia's Primary System write by Ajmal Hamidi. This book was released on 2010. A Planning-level Methodology for Identifying High-crash Sections of Virginia's Primary System available in PDF, EPUB and Kindle. The Virginia Department of Transportation (VDOT) has been developing safety performance functions (SPFs) as a way to identify sites with a potential for safety improvement more effectively. An SPF estimates the expected safety performance of a roadway as a function of its characteristics. Using SPFs, VDOT can identify which roads have a significantly higher number of crashes than would be expected based on site conditions. Other VDOT studies have developed SPFs with a microscopic perspective that separately examine individual intersections or discrete roadway segments. The purpose of this study was to develop an SPF-based methodology to conduct more intermediate-scale safety analyses. VDOT's Traffic Engineering Division indicated that such a methodology would be useful for corridor screening and planning-level applications. The scope of the study was limited to the following roadway types in Virginia's primary system: rural two-lane, rural multilane divided, rural multilane undivided, urban two-lane, urban multilane divided, and urban multilane undivided. For each type, roadway inventory data, traffic volume data, and crash data from 2003 through 2007 were compiled and integrated into a database. This study then took an approach that diverged from that of other SPF research to develop intermediate-scale SPFs. Instead of crashes at intersections and on roadway segments being separated, intersection and segment crashes were combined and mapped onto the appropriate roadway inventory links. In addition, site aggregation was performed to combine similar, adjacent roadway links into longer aggregated sites. SPFs were then generated from these aggregated sites through regression analysis. A site prioritization demonstration was then performed using the aggregate SPFs and aggregate sites to create lists of sites with the highest potential for safety improvement. Finally, a comparison of these lists and those generated by the critical rate method produced quantitative evidence of the advantage of the developed SPF-based methodology over the traditionally used critical rate method. Once implemented, the methodology developed in this study should enable VDOT to conduct corridor screening and planning-level analyses in a more effective and cost-efficient manner.
Safety Performance Functions for Intersections on Highways Maintained by the Virginia Department of Transportation
Safety Performance Functions for Intersections on Highways Maintained by the Virginia Department of Transportation - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Safety Performance Functions for Intersections on Highways Maintained by the Virginia Department of Transportation write by Nicholas J. Garber. This book was released on 2010. Safety Performance Functions for Intersections on Highways Maintained by the Virginia Department of Transportation available in PDF, EPUB and Kindle. In recent years, significant effort and money have been invested through research and implemented safety projects to enhance highway safety in Virginia. However, there is still substantial room for improvement in both crash frequency and severity. As there are limits in the available funds for safety improvements, it is crucial that allocated resources for safety improvement be spent at highway locations that will result in the maximum safety benefits. In addition, intersection crashes play a significant role in the safety conditions in Virginia. For example, crashes at intersections in Virginia for the period 2003 through 2007 account for 43.8% of all crashes and 26% of fatal crashes. Therefore, identifying intersections for safety improvements that will give the highest potential for crash reduction when appropriate safety countermeasures are implemented will have a significant impact on the overall safety performance of roads in Virginia. The Federal Highway Administration (FHWA) has developed a procedure for identifying highway locations that have the highest potential for crash reduction (ITT Corporation, 2008). A critical component of this method is the use of safety performance functions (SPFs) to determine the potential for crash reductions at a location. An SPF is a mathematical relationship (model) between frequency of crashes by severity and the most significant causal factors on a specific highway. Although the SafetyAnalyst User's Manual presents several SPFs for intersections, these were developed using data from Minnesota. FHWA also suggested that if feasible, each state should develop its own SPFs based on crash and traffic volume data from the state, as the SPFs that are based on Minnesota data may not adequately represent the crash characteristics in all states. SPFs for intersections in Virginia were developed using the annual average daily traffic as the most significant causal factor, emulating the SPFs currently suggested by SafetyAnalyst. The SPFs were developed for both total crashes and combined fatal plus injury crashes through generalized linear modeling using a negative binomial distribution. Models were also developed for urban and rural intersections separately, and in order to account for the different topographies in Virginia, SPFs were also developed for three regions: Northern, Western, and Eastern. This report covers Phases I and II of the study, which includes urban and rural intersections maintained by VDOT. Statistical comparisons of the models based on Minnesota data with those based on the Virginia data showed that the specific models developed for Virginia fit the Virginia crash data better. The report recommends that VDOT's Traffic Engineering Division use the SPFs developed for Virginia and the specific regional SPFs suggested in this report to prioritize the locations in need of safety improvement.
Pedestrian Facilities Users Guide: Providing Safety and Mobility
Pedestrian Facilities Users Guide: Providing Safety and Mobility - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Pedestrian Facilities Users Guide: Providing Safety and Mobility write by Charles V. Zegeer. This book was released on 2002. Pedestrian Facilities Users Guide: Providing Safety and Mobility available in PDF, EPUB and Kindle. This guide is intended to provide information on how to identify safety and mobility needs for pedestrians with the roadway right-of-way. Useful for engineers, planners, safety professionals and decision-makers, the guide covers such topics as: the Walking Environment including sidewalks, curb ramps, crosswalks, roadway lighting and pedestrian over and under passes; Roadway Design including bicycle lanes, roadway narrowing, reducing the number of lanes, one-way/two-way streets, right-turn slip lanes and raised medians; Intersections with roundabouts, T-intersections and median barriers; and Traffic calming designs.
Managing Speed
Managing Speed - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Managing Speed write by . This book was released on 1998. Managing Speed available in PDF, EPUB and Kindle. 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.
To Err Is Human
To Err Is Human - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook To Err Is Human write by Institute of Medicine. This book was released on 2000-03-01. To Err Is Human available in PDF, EPUB and Kindle. Experts estimate that as many as 98,000 people die in any given year from medical errors that occur in hospitals. That's more than die from motor vehicle accidents, breast cancer, or AIDSâ€"three causes that receive far more public attention. Indeed, more people die annually from medication errors than from workplace injuries. Add the financial cost to the human tragedy, and medical error easily rises to the top ranks of urgent, widespread public problems. To Err Is Human breaks the silence that has surrounded medical errors and their consequenceâ€"but not by pointing fingers at caring health care professionals who make honest mistakes. After all, to err is human. Instead, this book sets forth a national agendaâ€"with state and local implicationsâ€"for reducing medical errors and improving patient safety through the design of a safer health system. This volume reveals the often startling statistics of medical error and the disparity between the incidence of error and public perception of it, given many patients' expectations that the medical profession always performs perfectly. A careful examination is made of how the surrounding forces of legislation, regulation, and market activity influence the quality of care provided by health care organizations and then looks at their handling of medical mistakes. Using a detailed case study, the book reviews the current understanding of why these mistakes happen. A key theme is that legitimate liability concerns discourage reporting of errorsâ€"which begs the question, "How can we learn from our mistakes?" Balancing regulatory versus market-based initiatives and public versus private efforts, the Institute of Medicine presents wide-ranging recommendations for improving patient safety, in the areas of leadership, improved data collection and analysis, and development of effective systems at the level of direct patient care. To Err Is Human asserts that the problem is not bad people in health careâ€"it is that good people are working in bad systems that need to be made safer. Comprehensive and straightforward, this book offers a clear prescription for raising the level of patient safety in American health care. It also explains how patients themselves can influence the quality of care that they receive once they check into the hospital. This book will be vitally important to federal, state, and local health policy makers and regulators, health professional licensing officials, hospital administrators, medical educators and students, health caregivers, health journalists, patient advocatesâ€"as well as patients themselves. First in a series of publications from the Quality of Health Care in America, a project initiated by the Institute of Medicine
