Accident Modification Factors For Traffic Engineering And Its Improvements

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.

"This digest is an interim deliverable from NCHRP Project 17-25, 'Crash reduction factors for traffic engineering and ITS improvements,' which is being carried out under a contract with The University of North Carolina Highway Safety Research Center (HSRC) under the direction of David L. Harkey (Principal Investigator)."--P. [1].

This pioneering text provides a holistic approach to decisionmaking in transportation project development and programming, whichcan help transportation professionals to optimize their investmentchoices. The authors present a proven set of methodologies forevaluating transportation projects that ensures that all costs andimpacts are taken into consideration. The text's logical organization gets readers started with asolid foundation in basic principles and then progressively buildson that foundation. Topics covered include: Developing performance measures for evaluation, estimatingtravel demand, and costing transportation projects Performing an economic efficiency evaluation that accounts forsuch factors as travel time, safety, and vehicle operatingcosts Evaluating a project's impact on economic development and landuse as well as its impact on society and culture Assessing a project's environmental impact, including airquality, noise, ecology, water resources, and aesthetics Evaluating alternative projects on the basis of multipleperformance criteria Programming transportation investments so that resources can beoptimally allocated to meet facility-specific and system-widegoals Each chapter begins with basic definitions and concepts followedby a methodology for impact assessment. Relevant legislation isdiscussed and available software for performing evaluations ispresented. At the end of each chapter, readers are providedresources for detailed investigation of particular topics. Theseinclude Internet sites and publications of international anddomestic agencies and research institutions. The authors alsoprovide a companion Web site that offers updates, data foranalysis, and case histories of project evaluation and decisionmaking. Given that billions of dollars are spent each year ontransportation systems in the United States alone, and that thereis a need for thorough and rational evaluation and decision makingfor cost-effective system preservation and improvement, this textshould be on the desks of all transportation planners, engineers,and educators. With exercises in every chapter, this text is anideal coursebook for the subject of transportation systems analysisand evaluation.

This report provides guidance for the design and application of shoulder and centerline rumble strips as an effective crash reduction measure, while minimizing adverse effects for motorcyclists, bicyclists, and nearby residents. Using the results of previous studies and the research conducted under this project, safety effectiveness estimates were developed for shoulder rumble strips on rural freeways and rural two-lane roads and for centerline rumble strips on rural and urban two-lane roads.

This book increases the level of knowledge on road safety contexts, issues and challenges; shares what can currently be done to address the variety of issues; and points to what needs to be done to make further gains in road safety.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 409: Traffic Signal Retiming Practices in the United States explores practices that operating agencies currently use to revise traffic signal timing. The report examines the processes used to develop, install, verify, fine-tune, and evaluate the plans--