If might be talking out of my ass, but I vaguely remember there being something about road asphalt compositions being different- using more oil in the binder up north, to keep the freeze/ thaw from destroying the road, which also preventings the water from soaking i to it as deeply, making ice accumulate less, (more melted snow runs off the road instead of staying on the surface, and being less slick and adhered into the road.

The payoff being the extra binder makes roads breakdown faster, not to mention having them melt and become malleable under car tires if it gets too hot.