Human Factors Considerations in Disseminating Road Weather Information

Many state transportation agencies have developed and are using a variety of traveler information systems such as web sites, dynamic/variable messages, highway advisory radios, 511 telephone services and other traffic advisory and control systems to communicate information on road weather and road conditions to the public. However, little has been done to evaluate the content, usefulness and effectiveness of the road weather information and the means by which they are delivered to the travelers. Additionally, no standards or guidelines exist that identify the most effective content and methods by which different types of weather and road condition information can be disseminated to the public. This jeopardizes the safety and mobility of people who often have to travel in bad weather. The Federal Highway Administration (FHWA) Road Weather Management Program initiated a study in 2008 to examine human factors associated with road weather advisory and control information. The goals of the study are to identify the weather information requirements of travelers across a representative number of travel scenarios, evaluate the current state of the practice in weather-responsive traffic advisory and control strategies in terms of meeting those information requirements, and recommend ways to improve those practices including the development of a road weather information design guide. This paper discusses the results of the human factors study including analysis of existing literature, field surveys and focus group exercises that were undertaken to evaluate the effectiveness of road weather messages and dissemination methods. In addition, the recommended improvements and guidelines for road weather information communication and presentation that meet the needs of the drivers and travelers for different weather conditions and travel scenarios are presented.