Road Weather Information Systems (RWIS)

Inclement weather is often cited as a contributing factor in serious traffic collisions. In Canada, between 1999 and 2008, snowy, slushy, or icy road surface conditions were cited as contributing factors in 11.9% of collisions in which road users were killed, and 12.2% in which road users sustained injuries. (Transport Canada, 2012).

Road Weather Information Systems (RWIS) provide accurate and timely road weather information about hazardous road conditions that helps maintenance managers address situations before problems arise, thereby reducing operations and maintenance costs, increasing motor vehicle occupant safety, and reducing the environmental impacts of using salt and other de-icing agents (U.S. Department of Transportation, 2009).

Boon et al., (2002) noted that the potential benefits of RWIS only manifested when winter maintenance practices were changed significantly. The authors indicated that RWIS-enabled practices include anti-icing, reduced use of routine patrols, more cost-effective allocation of resources, the provision of better information to travellers, and the sharing of weather data.

The Ontario Ministry of Transportation (MTO) has had a comprehensive network of Road Weather Information System (RWIS) stations in place since the mid-1990s to provide highway maintenance staff with real-time atmospheric and pavement condition data to proactively make the most appropriate winter road maintenance decisions. During the winter season, real-time data is collected and uploaded to a secure web site every 20 minutes (7 days per week, 24-hours per day). In addition, 3 atmospheric forecasts and 2 pavement condition forecasts are generated daily. MTO and other road authorities in the province that own RWIS systems have reciprocal data sharing agreements in place to maximize the accessibility of this information to highway maintenance personnel throughout Ontario (Buchanan et al., 2005).

The U.S. Department of Transportation (2009) cited research conducted in Utah that demonstrated that the provision of detailed weather forecast information by staff meteorologists from the transportation management centre to winter maintenance personnel reduced labour and materials costs for snow and ice control activities, and yielded a benefit-to-cost ratio of 10:1.

The Finnish National Road Administration developed a road weather service system for both road-maintenance personnel and road users to improve the monitoring of road weather conditions and road maintenance (rendering that maintenance more systematic and timely). The automated information system sent actual and forecasted weather and road surface information to road maintenance personnel. The road weather information system was projected to yield a benefit-to-cost ratio of 5:1 by improving safety through reductions in collisions and casualties, vehicle maintenance costs, and improvements to travel times (Pilli-Sihvola et al., 1993).

Buchanan et al., (2005) cited the findings of the Swedish National Road Administration, which found that the benefit-to-cost ratio of RWIS was 2.5:1 for road authorities and 20:1 for the state economy.

Buchanan et al. (2005) also cited the findings of a benefit-cost study of the effects of RWIS on Mn/DOT’s maintenance activities and on the public, which was conducted by Minnesota’s Department of Transportation (Mn/DOT). The results of the study indicated that the benefit-to-cost ratio after installation was 2.1:1 for MnDot and 11:1 for the public (crash reductions, environmental benefits, and travel delays).

Scope of the Problem

• Transport Canada (2012). 1999-2008 National Collision Database. Retrieved from http://wwwapps2.tc.gc.ca/Saf-Sec-Sur/7/NCDB-BNDC/p.aspx?l=en

Evidence

• U.S. Department of Transportation (2009). Investment Opportunities for Managing Transportation Performance through Technology Research and Innovative Technology Administration (RITA), Washington, D.C. Retrieved from http://www.its.dot.gov/press/2009/transportation_tech.htm#_Toc219279390
• Boon, C.B., Cluett, C. (2002). Road Weather Information Systems: Enabling Proactive Maintenance Practices in Washington State (Report No. WA-RD 529). Washington State Transportation Commission. Retrieved from http://depts.washington.edu/trac/bulkdisk/pdf/529.1.pdf
• Pilli-Sihvola, Y., Toivonen, K., Kantonen, J. (1992). Road Weather Service System in Finland and Savings in Driving Costs. Transportation Research Record 1387, 196-200. Washington, D.C.: Transportation Research Board. Retrieved from http://trid.trb.org/view.aspx?id=379651
• Buchanan, F., Gwartz, S.E. (2005) Road Weather Information Systems at the Ministry of Transportation, Ontario. 2005 Annual Conference of the Transportation Association of Canada. Calgary, Alberta. Retrieved from http://www.tac-atc.ca/english/resourcecentre/readingroom/conference/conf2005/docs/s3/buchanen.pdf