Selecting the right material to apply
Every winter, millions of tons of snow and ice control materials are applied to North American roadways, sodium chloride chief among them. Applauded by highway safety advocates and economic development interests who extol safe and passable winter driving, use of deicers and abrasives has been accompanied by a half-century of concern and distrust by environmental groups and citizens wondering if their tax dollars are being well-spent. Too often, it seems, the decision on which material to apply and in what amounts has been seen as more art than science – and some people just don’t like “modern art”!
In May 2007, the Transportation Research Board published a new set of research-based “Guidelines for the Selection of Snow and Ice Control Materials to Mitigate Environmental Impacts.” The report incorporated the latest and best test results measuring 42 different deicing chemicals on the three key variables: how well they perform in melting snow and ice, how they impact the full range of environmental receptors and how they affect roadway and bridge structures.
The report includes a new tool used by winter maintenance professionals, a computerized mathematical model that crunches all these data, processes it by weightings selected by each agency, assign to represent the values of the local community, and – voilá – creates a customized recommendation to guide deicer selection. The process is flexible, transparent and utterly objective. Using real data, local agencies and policy-makers can plug in their local data, sensitivities and expectations and get a professional “consultation” on the best material for their purposes.