Identifying factors that affect crash injury severity and understanding how these factors affect injury severity is critical in planning and implementing highway safety improvement programs. Factors which can be categorized in to classes such as driver-related, traffic, environmental and geometric design were considered to develop a statistical model that can be used to predict the effects of these factors on severity of injuries sustained from crashes. Police-reported crash data obtained from the Ohio Department of Public Safety (ODPS) at selected freeway merging and diverging areas in the State of Ohio was used for the development of the model. A generalized ordinal logit model or partial proportional odds model was applied to identify the factors that tend to increase the likelihood of one of five levels of injury severity: No Injuries, Possible/Invisible Injuries, Non-incapacitating Injuries, Incapacitating Injuries, or Fatal Injuries.

This book (in three volumes) comprises the proceedings of the Fifth Conference of Transportation Research Group of India (CTRG2019) focusing on emerging opportunities and challenges in the field of transportation of people and freight. The contents of the volume include characterization of conventional and innovative pavement materials, operational effects of road geometry, user impact of multimodal transport projects, spatial analysis of travel patterns, socio-economic impacts of transport projects, analysis of transportation policy and planning for safety and security, technology enabled models of mobility services, etc. This book will be beneficial to researchers, educators, practitioners and policy makers alike.

The first and only comprehensive guide to best practices in winter road operations Winter maintenance operations are essential to ensure the safety, mobility, and productivity of transportation systems, especially in cold-weather climates, and responsible agencies are continually challenged to provide a high level of service in a fiscally and environmentally responsible manner. Sustainable Winter Road Operations bridges the knowledge gaps, providing the first up-to-date, authoritative, single-source overview and guide to best practices in winter road operations that considers the triple bottom line of sustainability. With contributions from experts in the field from around the world, this book takes a holistic approach to the subject. The authors address the many negative impacts on regional economies and the environment of poorly planned and inadequate winter road operations, and they make a strong case for the myriad benefits of environmentally sustainable concepts and practices. Best practice applications of materials, processes, equipment, and associated technologies and how they can improve the effectiveness and efficiency of winter operations, optimize materials usage, and minimize cost, corrosion, and environmental impacts are all covered in depth. Provides the first up-to-date, authoritative and comprehensive overview of best practices in sustainable winter road operations currently in use around the world Covers materials, processes, equipment, and associated technologies for sustainable winter road operations Brings together contributions by an international all-star team of experts with extensive experience in designing, implementing, and managing sustainable winter road operations Designed to bring professionals involved in transportation and highway maintenance and control up to speed with current best practice Sustainable Winter Road Operations is essential reading for maintenance professionals dealing with snow and ice control operations on highways, motorways and local roads. It is a valuable source of information and guidance for decision makers, researchers, and engineers in transportation engineering involved in transportation and highway maintenance. And it is an ideal textbook for advanced-level courses in transportation engineering.

"TRB's National Cooperative Highway Research Program (NCHRP) Report 730: Design Guidance for Freeway Mainline Ramp Terminals presents design guidance for freeway mainline ramp terminals based on current driver and vehicle behavior. Appendixes A to D to NCHRP Report 730 were not published as part of the print or PDF version of the report. They are only available electronically through the following links: Appendix A: Aerial View of Study Locations. Appendix B: Histograms of Observed Acceleration Rates. Appendix C: Verbal Instructions for Behavioral Study. Appendix D: Potential Changes Proposed for Consideration in the Next Edition of the Green Book (Note: Appendix D contains tracked changes that have been intentionally left intact--i.e., not accepted.)" Appendices are available at: http://www.trb.org/Highways1/Blurbs/167516.aspx--

Work zones are critical parts of the transportation infrastructure renewal process consisting of rehabilitation of roadways, maintenance, and utility work. Given the specific nature of a work zone (complex arrangements of traffic control devices and signs, narrow lanes, duration) a number of crashes occur with varying severities involving different vehicle sizes. This dissertation proposes a comprehensive discrete choice analysis of injury severity of crashes in work zones on both the crash and occupant levels, in roadway work zones through a comprehensive set of discrete choice econometric frameworks. Robust discrete choice modeling structures are introduced and applied in the field of work zone safety. This dissertation contains three (3) studies representing the empirical analysis conducted to address the following research questions:1. What factors may contribute to the injury severity levels of large-truck crashes in work zones? And what are the robust analytical methods to recognize such factors?2. How do specific work zone configurations affect factors contributing to the levels of injury severity of work zone crashes?3. How does the specific work zone-component-area where a crash has occurred affect factors contributing to the injury severity levels of work zone crashes?The first study investigates the causal factors contributing to injury severity of large truck crashes in work zones. The second study investigates the causal factors contributing to the injury severity of passenger-car occupants for crashes occurring in different work zone configurations (lane closure, lane shift/crossover, shoulder/median, intermittent, and other). The third study investigates the causal factors contributing to driver & rsquo;s injury severity in the different work zone component-areas (advance-warning, transition, activity, and termination areas). The first study compares a comprehensive set of discrete choice modeling structures; Multinomial Logit (MNL) model, Nested Logit (NL) model, Ordered Logit (ORL) model and Generalized Ordered Response Logit (GORL) model. The second and third studies developed the Mixed Generalized Ordered Response Probit (MGORP) modeling framework to conduct the proposed analysis to answer the second and third research questions. The empirical analysis was conducted using work zone crash database in 10 years of the Highway Safety Information System (HSIS).

How should data involving response variables of many ordered categories be analyzed? What technique would be most useful in analyzing partially ordered variables regarded as dependent variables? Addressing these and other related concerns in social and survey research, Clogg and Shihadeh explore the statistical analysis of data involving dependent variables that can be coded into discrete, ordered categories, such as "agree," "uncertain," "disagree," or in other similar ways. The authors emphasize the applications of new models and methods for the analysis of ordinal variables and cover general procedures for assessing goodness-of-fit, review the independence model and the saturated model, define measures of association, demonstrate the logit versions of the model, and develop association models as well as logit-type regression models. Aimed at helping researchers formulate models that take account of the ordering of the levels of the variables, this book is appropriate for readers familiar with log-linear analysis and logit regression.

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.