For as long as most people can remember, we’ve been using salt to treat roadways and keep them safer during winter. However, when did we start using road salt and how did it come to be? Road salt first appeared in the United States when New Hampshire began to experiment with granular sodium chloride in 1938. By the winter of 1941-1942, the state began using salt on local roads and highways. Eventually, other states caught on and began using salt as well. Today, the U.S. alone uses between 10 and 20 million tons of road salt each winter. That’s 10 times the amount of salt we use in processed foods. So, where does all of this salt come from? Most rock salt comes from underground seams of crystal salt that form from the evaporation of ancient seas. To harvest the salt, miners follow underground shafts and break off slabs of the salt crystal using dynamite or powered shoveling machines. The salt is then put onto a truck or conveyor belt and taken to be crushed into what we know as rock salt. One of the biggest salt mines in the U.S. is found underneath the city of Detroit. As for salt’s success, studies have shown that road salt reduces car crashes by 88% and that deicing with road salt pays for itself in just 25 minutes after the salt is spread. Clearly, the use of road salt during winter weather is worth the time and well worth the investment.
