1. I have a steep driveway, and when it was poured I looked into putting a heating element in it for about 20 feet to keep the ice off. I don't remember the details, but it was a fantastic amount of money to do it, and required special heavy amperage power connections. I abandoned the idea.

2. If using heating elements was cost efficient to keep ice off, you can bet the military and civilian airfields would use it to keep the runways clear. They do not. My father used to work at an Alaska military airbase, he said that snow and ice removal on the runway was a 24/7 operation. They weren't fools, if the heating element idea would work they'd have used it.