The State of Alaska did a case study on this product here it is:
During 1997-1998, most of the effort centered on the use of sand pre-wetted with MgCl. Before and after a storm event, sand was applied to the roadway and MgCl was sprayed onto the sand as it left the hopper belt. As the pre-wetted sand hit the Snow pack, it melted, diluted, and refroze, embedding the sand into the pack. The sand provided immediate, long lasting friction with very little sand blown into the ditch by traffic. AKDOT experience found that the chemical continued to work, migrating through the pack over the next couple of days, turning the pack into a loosely arranged, oatmeal consistency. This was easily plowed off and some of it sub-limated (changed from a solid to a vapor) as traffic aerated the mixture. This was the first winter when Valdez experienced mostly ice-free roads. Sand use was reduced by 30 percent. After experimenting with different application rates,
AKDOT found 7 gallons per ton optimal for conditions
Here is the link for the case study.
As you can see SnowMelt2006 the salt mines cannot keep up and Kaw Valley came up with a solution that other states have been using for years. By the way where is your salt?
Here is the web address for Kaw Valley which not a spam www.kawvalleyco.com