Establish a centralized database for all winter maintenance-related weather information.
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

This project demonstrated the value of establishing a consolidated, Internet source of road-weather information that includes many types of data from a wide variety of sources. The ITD experience with RWIS data integration and sharing provides several suggestions for RWIS deployers:

  • Participate in weather data sharing partnerships. Through their participation in the MesoWest weather information sharing consortium coordinated by the University of Utah, for a very nominal initial investment in time and money (a few thousand dollars), the ITD was able to access data from a large number of ESS operated by a wide range of organizations throughout Idaho and in bordering areas. The utility of the other organizations' ESS for the ITD varies greatly, depending on what data are collected, where the station is sited, and how well the station is calibrated and maintained. Not all of the other organizations' stations will provide a long-term alternative to implementation of ITD's own ESS. At a minimum, however, the ITD has found that tapping into other organizations' ESS data to be a good short-term strategy for filling gaps in RWIS data collection coverage.
  • Provide winter maintenance personnel with an accessible, consolidated source of weather information. Most of ITD maintenance personnel that were interviewed and surveyed found significant value in the RWIDS webpage and used it frequently. Monthly RWIDS sessions peaked at just over 2,500 sessions during mid-winter (January and February). About 78% of surveyed users consulted the site at least multiple times per week during the winter. Maintenance users found value in most of the wide variety of data presented on the site. Nearly all (about 80%) of the data types were accessed in at least 10% of web sessions. However, RWIS operators should expect that the utilization of a consolidated weather data source such as RWIDS would be significantly lower among users lacking high-speed Internet access and/or in areas where there were few ESS of interest.
  • Do not assume a consolidated source of winter maintenance decision support information will serve as a complete "one-stop-shop". Although most maintenance personnel found the RWIDS webpage useful, most of them continued to rely on other sources of information as well. In some cases they consulted websites for the same information included on RWIDS (e.g., going directly to the National Weather Service website) because it was easier to access. Therefore, RWIS operators should expect that even a well-designed consolidated weather information source would not completely replace other information gathering strategies.
  • Develop a common data specification for ESS data integration. In the course of integrating data from their two existing brands of ESS and establishing a single user interface, the ITD established a format for ESS data. They have been successful in requiring ESS vendors to comply with that format. Having established a means to integrate data from various brands of ESS, the ITD has been able to purchase stations from different vendors, at significantly lower costs, saving about $7,500 per station in a recent procurement.

This lesson suggests that sharing ESS data with other organizations is a very cost-effective way to enhance weather data collection coverage. The ITD experience also indicates that providing a consolidated source for a wide range of winter weather information to state highway maintenance personnel contributes to their effectiveness and productivity. Finally, several maintenance personnel have indicated that access to good ESS data may reduce the amount of field patrolling necessary to observe road and weather conditions. If so, providing maintenance personnel with road weather information could also provide energy and environmental benefits, i.e., reduced fuel consumption and vehicle emissions.