We generally do not get any serious or at least consistent winter precipitation to justify the cost of snow removal for an event that may or may not happen within a five year span in NC. We get what...one maybe two minor snows a year (excluding the mountains). The ones that don't know how to drive in the snow are actually the very transplants that make fun of the locals for "not being able to drive in the snow". That was actually a subject WRAL touched on with NCSHP data a few years back. Most locals stay off the road because we know better. We know the roads are going to be icy and they are going to be that way until it melts which is on average an inconvenience of 48 hours. Do the schools close for insane low amounts of snow? You bet...because the liability isn't worth it.
Dramatic temperature swings are the worst.
Ice on the road isn't a problem, of course it's no where near as grippy as pavement but driving on cold frozen ice is generally manageable (as long as you have Winter Tires).
WET icy roads on the other hand are a huge problem. If you get rain on top of ice that's just about the slickest thing known to man.