This project used surveys to evaluate the impacts of improved Road Weather Information Systems and Highway Advisory Radio on the behavior, safety, and efficiency of commercial vehicle operators (CVOs), regional traveler information seekers, and WSDOT personnel responsible for maintaining operations along the US-395 corridor, north of Spokane, Washington.
Prior to the project, closed circuit television (CCTV) camera coverage and on-site Highway Advisory Radio (HAR) systems were not available. Internet traveler information only covered conditions in the immediate Spokane area and traffic reports were only available periodically on radio stations. In 2002, the project integrated two Environmental Sensing Stations (ESS) with a regional Road Weather Information System (RWIS) and Transportation Management Center (TMC), and deployed two mobile HAR systems to broadcast traveler information in the immediate areas of Loon Lake and Laurier area on US-395, and at Sherman Pass on SR-20.
The two new ESS installations were equipped with pole mounted CCTV cameras and sensors to measure pavement temperature, surface condition, solution freeze point, sub-grade temperature, wind speed/direction, precipitation type/intensity, visibility, air temperature, relative humidity, and atmospheric pressure. The data collected at each site were transmitted to WSDOT operators and relayed to the TMC in Wenatchee where pass condition information was posted on the WSDOT website and made available at a toll-free telephone number. HAR trailers were programmed to broadcast road and weather restrictions information using limited range radio transmitters.
The evaluation project was designed to measure changes in users’ decisions before and after deployment with consideration given to maintenance procedures, trip timing, trip routing, and level of preparedness. Baseline data (before equipment installation) were collected during the winter of 2000-2001, and post-deployment data were collected in the winter of 2002-2003. The evaluation team estimated that the duration of the post-deployment period (December 2002 through March 2003) would be sufficient time to allow travelers and operators to become aware of system components and use the information provided.
During the winter of 2002-2003, after the new information sources were available for several months, the response of general travelers to RWIS information was determined using a web-based survey on the WSDOT’s website. Web-page banners proving access to the survey were activated on March 7, 2003, and then were removed one month later on April 7, 2003.
237 respondents completed two or more questions, and 13 surveys were incomplete. Respondents ranked their opinion on a range of -2 (strongly disagree) to +2 (strongly agree) for each question.
The bullets below highlight major findings. The author noted the results were based on a self-selected survey group, therefore, they were not a representative sample of visitors to these web pages, and the observations made are not attributable to all travelers in this region. The Internet survey approach was implemented as a way to efficiently reach a large number of respondents considered to be traveler information seekers.
- 94 percent agree or strongly agree that the website road weather information made travelers better prepared for their trips. Over half of the respondents (56 percent) agreed the information helped them avoid travel delays.
- Personal business was the most frequently cited type of trip for which respondents said they accessed road weather information on the web site.
- Approximately 93 percent of respondents were relatively frequent users of this WSDOT web information, reporting six or more visits to the web site between December 1, 2002 and the time of the survey (March 2003).