An evaluation of road deicing alternatives directed by Xianming Shi and Laura Fay of the Western Transportation Institute at Montana State University and conducted for the Colorado Department of Transportation examined common chloride, acetate and ag byproduct deicers and concluded:

• Corrosion-inhibited salt (NaCl) and mag chloride (MgCl2) is preferred "until better deicer alternatives are identified."
• Training, calibration and minimized application rates -- the essence of the Salt Institute's Sensible Salting program -- are key to minimizing adverse environmental impacts.
• Chlorides in the environment did not exceed the water quality standard. This is an aesthetic standard for taste, not a health standard.

The report formulated a "deicer composite index" similar to that published a few years ago as NCHRP Report 577 . The model, like that of Report 577, allows local customization. Using the current weighting for Colorado users, the method validated current CDOT user priorities ("the inhibited liquid MgCl2 deicer products present a better alternative than either the non-inhibited NaCl or the K- or Na-acetate/formate deicers").

Hundreds of snowfighters gathered at the Ontario Good Roads Association’s Snow & Ice Colloquium earlier this week and celebrated the steady progress of their efforts to upgrade their salt management operations.

As the lead-off speaker, I pointed out that “Sustainable Salting” in current parlance is a direct evolutionary outgrowth of the Salt Institute’s Sensible Salting program begun in the 1960s. The real progress, however, in Canada, has taken place in the past decade with adoption and implementation of a Road Salts Code of Practice.

Oftentimes, satisfaction is achieved by adopting best management practices and basking in the glow that all that can be done is being done. Canada, however, has gone a step further: it has put in place an independent investigation of whether the recommended best practices are actually delivering environmental improvements. A half day of the two day conference heard from the scientists conducting those studies.

Dr. Michael Stone of the University of Waterloo reported a survey showing that more than 70% of Canadian snowfighting agencies have adopted written salt management plans (SMPs) governing their storage and application of salt (which represents 97% of the deicing materials used in the country). Unfortunately, surveys show that many SMPs may not be tied directly to operations; 43% haven’t been modified in the past five years. In another successful area, 63% of the agencies conduct annual operator training (though only 21% train snowfighting contractors). And more than half (51%) have identified “salt vulnerable areas” in their SMPs, areas where special salt management practices are utilized.

Overall, snowfighting technology and techniques are advancing sharply. Reports filed with Environment Canada show 1) salt usage is up sharply the past two winters, 2) 95% of the salt storage facilities are under cover and on impermeable pads, 3) 85% of snowfighting trucks use computerized ground-speed spreader controls, 4) 43% of the vehicles can do pre-wetting and 30% of the agencies employ anti-icing strategies.

Measurement not only leads to better accountability tomorrow, but helps today for us to see the need for more action in closing out antiquated, salt-wasting spreader technologies, giving better guidance for identification of vulnerable local ecosystems and training private sector snowfighters.

Significant impacts on U.S. transportation planning are forecast in a new report about to be released by the Transportation Research Board, an arm of the National Academies of Science. TRB Special Report 290: Potential Impacts of Climate Change on U.S. Transportation concedes that "Little consensus exists among transportation professionals that climate change is occurring or warrants action now." But the report identifies "plausible future scenarios" which represent "significant challenges for transportation professionals." The committee "finds compelling scientific evidence that climate change is occurring, and that it will trigger new, extreme weather events."Special Report 290 identifies "five climate changes of particular importance to transportation and estimatedsthe probability of their occurrence during the twenty-first century." Included, as #4, is "Increases in intense precipitation events. It is highly likely (greater than 90 percent probability of occurrence) that intense precipitation events will continue to become more frequent in widespread areas of the United States." Louisiana being America's largest salt-producing state, the salt industry will be particularly interested in the report's prediction of increased coastal flooding, particularly of the Gulf coast and drier conditions in the upper Midwest "resulting in lower water levels and reduced capactiy to ship agricultural and other bulk commodities." Among the adaptive operational responses, the first example identified is "Snow and ice control accounts for about 40 percent of annual highway operating budgets in the northern U.S. states" and "operational responses are likely to become more routine and proactive than today's approach of treating severe weather on an ad hoc emergency basis." Roadway designers are encouraged to recognize the likelihood of more freeze-thaw cycles. In this, of course, snowfighting professionals are already well advanced in their "adaptation." The committee speculates that there will be "benefits for safety and reduced interruptions if frozen precipitation shifts to rainfall."

Canadian discussions and studies are more advanced than in the U.S. and also predict impacts on use of road salt for winter maintenance. In "Climate Change and Ontarios's Winter Roads: Trends and Impacts on Ontario Winter Road Maintainence Ops" and "Climate Change Impacts and Adaptation: A Canadian Perspective," experts agreed that salt usage in southern and western Ontario would be unchanged by global warming, but that salt usage would increase in northern and eastern parts of the province.