Frost alone can cause substantial traction issues on certain road surfaces, namely bridge decks. Thus the preventative application of materials there when frost is in the forecast. We do so here using a mag chloride solution applied by a tank mounted on a trailer behind a stake body F450. Long term history tells us where it needs to go - from accident records and institutional knowledge.
Until the consumer can be convinced that the investment in snow tires is cheaper, the demand for road salt will continue to prevail. On the service provider side, we have extensive manuals on how to apply, when to apply, how much to apply, etc,,, along with calibrated spreaders and inventories after every event. We've reduced our salt application rates by nearly half with no apparent drop in levels of service by better prodict selection and smart application.
Even in a cold state like MN, I am looked at like I am from mars when I talk about my snow tires. Everyone I have convinced that they are worth the investment has been shocked after buying them, and now swear by them like I do.