Overview
Advance warning signals (AWS) provide information warning drivers in advance of the end-of-green interval for an approaching signali zed intersection. The purpose of this research was to develop guidelines for the placement of AWS in Utah, both c onditions to evaluate the need for AWS installation and guidelines for the AWS system design. The conditions were based on a detailed literature review and were developed using the Policy Delphi method. Six conditions are recommended and discussed in detail, including: limited sight distance, posted speed, isolated intersection, high crash rate, approach grade, and heavy vehicle traffic volume. The guidelines for the AWS system design included details about three components: AWS component, advance detection component, and signal timing component. An evaluation matrix was developed by the Policy Delphi method for the purpose of evaluating and prioritizing a group of intersections for AWS installation.