Traffic Signal Warrants

As part of a project conducted for the Texas Department of Transportation, the Texas Transportation Institute produced this revised set of guidelines for conducting a traffic signal warrant analysis. Traffic signals are one of the most restrictive forms of traffic control that can be used at an intersection. In order to ensure that the use of traffic signals is limited to favorable situations, practitioners have developed a series of traffic signal warrants to define the minimum traffic conditions that should be present before a traffic signal is installed. The application of these traffic signal warrants can be complicated at times. The general public, elected and government officials, and even some practitioners sometimes misunderstand the signal warrants. This document provides detailed guidelines on how to use the traffic signal warrants to evaluate the need for installing a traffic signal. It addresses many of the issues that have typically been left to interpretation and is intended to improve the consistency of the warranting process. This second edition is an update of the first edition, which was originally published in 1998. Since that time, the federal and state traffic signal warrant guidelines have been substantially revised and reformatted.