Every winter, the United States spreads between 10 and 20 million tons of rock salt over icy roads. In total, the country spends $2.3 billion on de-icing for highways alone - this cost covers plowing, salt and other methods.
Salt is effective up to a certain point because it lowers the freezing temperature for water, but the environmental impacts can be devastating. A study from the University of Minnesota found that as much as 70 percent of road salt gets washed into waterways like lakes and rivers. This salt decreases fish populations and can alter their development.
"With a four-lane highway, you have 16 tons of salt per year in a one mile segment [in Washington State]," said Xianming Shi from Washington State University. "In 50 years, that's about 800 tons of salt in that one mile and 99 percent of it stays in the environment. It doesn't degrade. It's a scary picture."Sand, the other de-icing solution, is not much better because sand is disappearing. Between 75 and 90 percent of the world's beaches are getting blown away by storms or eaten away by rising sea levels. The rest of it is going to cement industries, the glass industry and fracking. And desert sand is not a feasible replacement - it's too thin and smooth to adhere to surfaces.
Reports from the Environmental Protection Agency indicate that a third de-icing strategy - chemicals - aren't great either. They affect oxygen levels in waterways and can kill fish downstream from storm-water outlets.
A recent study from the Washington State University has been looking at greener alternatives. That's where vodka comes in - or at least, the byproducts of vodka. Researchers suggest using barley residue from vodka distilleries to sprinkle on the roads to prevent water from becoming ice.
Another popular alternative has been beet juice. Beet juice has to be used with salt because it traps the salt and prevents it from escaping into the ground. But this solution is also problematic because beet juice has a lot of sugar, which can also be harmful to the environment.
The answer to the de-icing problem, some scientists say, will be a combination of all the solutions that have already been developed.
"Our ultimate goal is to apply the best amount of salt, sand or deicers at the right location at the right time," said Shi.