That liquid de-icer crap there using on the roads now is calcium chloride, way more corrosive than salt and way more harmful to the environment. Salt will melt ice but once the ice is melted it will re freeze, calcium chloride won't freeze and will mix with water and ice their for preventing it from re freezing, making it an apply once and done type of thing, plus its is incredibly cheap. When you combine the fact that it needs fewer applications and its so cheap, it saves municipalities hundreds of thousands of dollars a year. As usual if it saves a buck everything else is trivial.