Rock salt is a thawing agent. It lowers the freezing point of water.

• Preventive gritting: When the weather forecast looks bad, you can grit preventively to combat first slipperiness. As long as temperatures do not get too low and precipitation is limited, preventive gritting often suffices. By gritting sensitive surfaces preventively, snow and sleet will have less of a chance to adhere to the surface.
• Curative gritting: Gritting from the moment snow or sleet has started, with the goal of keeping the surface passable, or to get it to a passable level as quickly as possible.
• Repressive gritting:Gritting after roads have become slippery. This will have an additional preventive effect on future precipitation.