The City of Kamloops, British Columbia implemented an anti-icing and pre-wetting program to reduce wintertime accidents, decrease winter maintenance costs, improve road salt management, and reduce the negative impacts of salt on the environment.
Anti-icing was deployed as a proactive approach in areas where liquid chemicals could be applied early enough (prior to precipitation) to prevent snow or ice from bonding on roadway surfaces. Pre-wetting was used as a reactive measure to improve conditions on roadways already covered in snow and ice. In these areas roadway surfaces were treated with pre-wet solid salts and abrasives to enhance ice melting, and reduced the tendency of dry materials to scatter and bounce off roadways.
The Insurance Corporation of British Columbia (ICBC) took interest in the project in 1996 and provided funds to conduct field trials and evaluate the potential of the program to improve safety and reduce winter-related accident claims. During the winter of 1996-1997, two liquid chemical dispensing trucks were deployed to distribute magnesium chloride (MgCl2) as a liquid anti-icing agent. Other trucks having dry hoppers and spinners were modified to include additional liquid chemical tanks and spray nozzles that enabled them to pre-wet the dry abrasives and salts as they were being applied.
To improve timing for anti-icing and pre-wetting applications the program was supported by the use of road weather information systems (RWIS), infrared thermometers for reading pavement temperatures, and improved forecasting techniques.
Evaluation data were collected during a three year field trial (1997—2000). Although the data collected were not applied to a benefit-cost analysis, the report indicated the program improved safety and reduced maintenance costs.
The report indicated that the cost of operations for anti-icing over a 72-hour period was approximately 58 percent less than the cost of traditional operations involving granular salt over the same 72-hour period.
During the first year of operations, pre-wetting techniques decreased abrasives usage by approximately 1,237 metric tons saving the City of Kamloops approximately $80,800. In addition, the reduced usage resulted in lower spring clean-up costs saving the City approximately $14,844 in sweeper costs.
"ICBC," Web site URL www.icbc.com. Insurance Corporation of British Columbia, North Vancouver, B.C. Last Accessed 15 April 2008.
ICBC examined the safety benefits of liquid anti-icing and compared them to the impacts of traditional de-icing methods. The ICBC report found that there was a 73 percent reduction in accidents caused by snow, ice, or slush conditions on roads treated using anti-icing methods. In addition, ICBC internal records indicated that anti-icing contributed to a 40 percent reduction in claims on days with snow, ice, or slush. This reduction translated into a total of 1,229 fewer claims for the three winters of 1997-1998 to 1999-2000, and saved approximately $4,000,000 in claim payments.