In Idaho, 80 percent of motorist surveyed who used Road-Weather Integrated Data System information as a traveler information resource indicated that the information they received made them better prepared for adverse weather.
Made Public Date


United States

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

Summary Information

In November 2002, the Idaho Transportation Department (ITD) completed an enhancement of their Road-Weather Information System (RWIS). The project had four objectives:
  • To provide more information, and to make the information more accessible, to ITD maintenance personnel in support of winter road maintenance decision making;
  • 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);
  • To incorporate RWIS data into the ITD "Road Report" traveler information Web page; and
  • 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.

The evaluation of the ITD RWIS integration project employed a before-and-after study approach focusing on three major areas: RWIDS as an ITD maintenance information resource, RWIDS as a traveler information resource, and RWIDS as a data integration platform. Before (pre-deployment) data were collected in 2001 and 2002, the system was made operational in November 2002, and ITD maintenance personnel were trained during the first winter season (2002—2003). After (post-deployment) data were collected during the second winter season (2003—2004).


ITD maintenance personnel were interested in a wide range of data, but most were interested in the same basic type of information popular with the general public, such as camera images and current and forecast weather information.

Travelers perceived enhanced safety through the use of the RWIDS Web site. Eighty (80) percent of online survey respondents who used the RWIDS agreed that the information they received made them better prepared for road-weather conditions. Seventy-six (76) percent indicated that the information helped them drive more carefully.

All 31 of the ITD maintenance personnel that responded to the survey identified at least one way in which the RWIDS Web site improved their decision making, and almost all of the respondents cited multiple benefits. The most commonly cited benefits included an improvement in the timing of road treatments (start earlier or later), and an improved ability to forecast resources for a particular storm event. Both of these benefits were cited by 60 percent of the 31 respondents.

The accident analysis conducted to evaluate the safety benefits of RWIDS was inconclusive as a result of the small sample size.