[thackney]

It would take a huge amount of steam.

I have designed Heat Trace systems to keep ice off sidewalks and driveways. It takes a large amount of energy to overcome constant exposure to a frozen environment without insulation. The heat loss is continuous and it takes a lot of energy to maintain the temperature above freezing.

[norraad]

Ok, so it takes alot of steam, lets do it and charge the amortized cost against environmental damage, medical costs(from accidents), road and vehicle repair.

Plus the pleasure and prestige of driving dry safe roads no matter what the weather, it's well worth it.