Because traffic signals play a key role in enhancing safety, the Federal Highway Administration (FHWA) recently produced a comprehensive handbook that explains methods to evaluate the safety and operation of signalized intersections and that highlights tools to remedy deficiencies. The guide, titled Signalized Intersections: Informational Guide (FHWA-HRT-04-091), provides information and tools that can help traffic engineers, project managers, and other transportation professionals conduct insightful assessments of intersections and understand the tradeoffs from potential improvement measures. This article describes the use of this new guide and explores how the guide includes examples of innovative treatments and best practices used by jurisdictions across the United States. These examples include low-cost measures such as improving signal timing and signs, and more expensive measures such as reconstructing intersections or grade separations. The author notes that the guide takes a holistic approach to signalized intersections, considering the safety and operational implications of a particular treatment on all system users, including motorists, pedestrians, bicyclists, and transit users. Other topics covered are intersection basics, geometric design, signal pole layout, analysis methods, planning for safety, and solutions to intersection deficiencies. The article concludes by noting that beginning in the spring of 2005, the National Highway Institute will offer a workshop on using Signalized Intersections: Informational Guide to develop intersection projects. The workshop will focus on a case study in which participants assess problems at an intersection and identify alternatives to improve it. To register, visit http://www.nhi.fhwa.dot.gov.
Abstract