Integrate various types of road weather information to promote utilization by the public.
An Idaho Transportation Department experience in Road-Weather Information System integration.
Made Public Date


United States

Final Evaluation Report: Evaluation of the Idaho Transportation Department Integrated Road-Weather Information System


In November 2002, the Idaho Transportation Department (ITD) completed an enhancement of their Road-Weather Information System (RWIS). The project had four objectives: 1) To provide more information, and to make the information more accessible, to ITD maintenance personnel in support of winter road maintenance decision making; 2) To allow data from environmental sensing stations deployed in the future by the ITD to be integrated with data from their two current brands of environmental sensing stations (ESS); 3) To incorporate RWIS data into the ITD "Road Report" traveler information Web page (; and 4) Expand RWIS data collection coverage by incorporating non-transportation weather station data.

The project created a new page, the Road-Weather Integrated Data System (, or "RWIDS," on the Road Report traveler Web site. The Web page consolidated data from several relevant sources: ITD's two different brands of ESS (previously accessible only to ITD maintenance personnel via two separate user interfaces) as well as a number of ESS, within and bordering Idaho, operated by a wide range of organizations. The Web page also incorporated additional types of weather information drawn from sources including: non-transportation weather data from Meso West consortium, ITD closed-circuit television camera views, and National Weather Service satellite and radar images, watches and warnings. A password-protected version of the RWIDS Web page, containing printing and e-mail alert features not available to the public, was made available to ITD maintenance personnel. This lesson is based on a Federal Highway Administration sponsored independent evaluation of the ITD RWIS Integration project.

Lessons Learned

There appears to be interest among travelers in receiving detailed road-weather information (i.e., more than a short narrative of road surface conditions) via the Internet. However, to promote utilization of the information, the RWIS deployers should integrate the information such that the website satisfies travelers' "bottom line" travel advisory needs. These lessons are discussed below.

  • Provide extensive road-weather information. The ITD experience suggests that travelers are interested in expanded winter road-weather information. The overall utilization of the Road Report website, which includes the traditional (pre-RWIDS) road surface condition information and the new RWIDS webpage, increased dramatically (169%) with the addition of the RWIDS webpage. Road Report users themselves expressed strong support for the on-line road weather information resource. Eighty percent of Road Report survey respondents agreed that the information helped them better prepare for road-weather conditions, and 76 percent of the respondents indicated that the information helped them drive more carefully. Sixty-three percent of respondents indicated that the RWIDS has resulted in the change of time of travel and 48 percent had canceled their trips.
  • Integrate discrete road-weather data to satisfy most users. Although many Road Report website users consulted the RWIDS webpage — suggesting an interest in additional information, as noted above — during 80% of sessions, the users penetrated no further than the RWIDS homepage. That is, few users accessed any of the wide range of specific, discrete information available on the RWIDS webpage. For example, camera images, the most popular type of specific information available via the RWIDS page, were accessed in only about 20% of sessions. There was little or no apparent interest in pavement conditions, National Weather Service watches and warnings, weather radar images, National Weather Service forecasts, weather satellite images, or road closure information. This suggests that travelers are unable or unwilling to synthesize a variety of discrete, unconnected road-weather information. Therefore, deployers providing such information should integrate it, such as by developing meaningful "bottom line" travel advisories or grouping data by roadway segment.

This lesson suggests that detailed road weather information is of great interest to travelers and contributes to their satisfaction. However, such information should be provided in the form of meaningful travel advisories for roadway segments. Also, the high percentage of Road Report users who reported that the information helped them better prepare for road-weather conditions and to drive more safely indicates that providing useful road-weather information can improve traveler safety as well.