An analytical model for interpreting driver comprehension of warning signs

Warning signs are used in the highway environment to warn the driver of a potential hazard located on or near the highway. The Manual on Uniform Traffic Control Devices (MUTCD) contains warrants and standards for the application, design, and placement of warning signs. Uniformity is one of the key concepts of the MUTCD. Uniformity aids driver comprehension of warning signs by providing the information in a consistent manner. However, several inconsistencies have crept into the current system of warning signs. These inconsistencies have resulted from numerous revisions to warming sign principles over many years. Many of these revisions have been based on the findings of research on driver comprehension of warning signs. However, most of this research has focused on one or a limited number of warming signs. There have been few studies which have evaluated the entire system of warning signs with the intent of providing consistent warning information about potential hazards.;This research evaluates the basic warning sign principles as a system, with an emphasis on communicating potential hazard information in a consistent manner. The research includes a review of the MUTCD principles for warning signs. It also includes an evaluation of the basic principles for general warning messages and how those principles might be adapted to the highway environment. Revised warning signs principles are developed from the MUTCD and general warning principles. Existing warning signs are then evaluated with respect to these principles. The results of these evaluations are used to select ten warning signs for further evaluation. Driver comprehension of the selected standard signs and alternative sign designs is measured in two surveys. The results of the surveys and the other evaluations are used to recommend changes to the warning sign chapter of the MUTCD.;Some of the recommended changes to the warning sign chapter of the MUTCD include: suggested organization of the warning sign chapter, restructuring the individual series of warning signs, additions and deletions of warning signs to the MUTCD, and recommended uses of warning signs.