How cold is too cold for road salt to be effective?

When snow is in the forecast, roads are often pre-treated with a layer of salt to prevent the formation of ice.

You're using too much salt to de-ice your driveway — here's how to do it the right way

As the wintery weather arrives, you might find yourself grabbing a bag of salt ready to de-ice your driveway. But, before you sprinkle it absolutely everywhere, stop and re-think your de-icing ...