Guidelines for Disseminating Road Weather Advisory & Control Information

Overview

These guidelines build on previous work dating back to 2008 to develop specific recommendations for communicating road weather information (content, format, and timing) in a way that is consistent with what travelers need, want, and will use when making travel decisions. They are intended to augment—not replace—the guidance provided in the Manual on Uniform Traffic Devices (MUTCD) and other guidance documents relevant to the presentation of traveler information. Evaluation of preliminary guidelines was conducted through review and use by a broad group of transportation and road weather officials who were surveyed and interviewed, resulting in modifications to the guidelines. They have the unique focus of providing the best available data on user performance and driver behavior relevant to the topic of road weather messages, and are intended to be used as a day-to-day resource and to support operator training. Guidelines are presented on three dissemination methods: dynamic message signs (DMS), auditory messages including Highway Advisory Radio (HAR) and 511, and websites. They cover content and wording of messages, message presentation and layout, and communication of information about urgency or certainty of road weather condition. The presentation is a quick-reference format with numerous example messages that are easy to find and to apply. The document also includes tutorials that provide useful background or supplementary information about human factors issues that cut across multiple guidelines.