Author: Aaron Paul Jensen

Publisher:

Published: 2007

Total Pages: 120

ISBN-13:

Advance warning signals (AWS) provide information warning drivers in advance of the end-of-green phase for an approaching signalized intersection. The purpose of this research was to develop guidelines for the placement of AWS in Utah, both conditions to evaluate the need for AWS installation and guidelines for the AWS system design. The conditions were based on literature of other transportation agencies that had similar AWS systems and were developed using the Policy Delphi method. The Policy Delphi method is the development of a specific policy area through the means of discussion by a committee of experts correlating views and information involving opportunity to react and assess different viewpoints until the committee is in agreement over the policies being recommended. 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. A total of 24 intersections were identified by the Utah Department of Transportation for this project that helped to develop and verify the conditions and evaluation matrix. The recommended guidelines and evaluation matrix results are described.