. There are roads on my route that gain 1400 vertical feet of altitude in 3 miles.
A "dusting" on the valley floor can mean 6" of wet, heavy slush up on the mountian. Many of the roads and driveways are steep with multiple switchbacks and no guardrails. You cant make it without chains. When it melts and then re- freezes at night its even worse.
Snow on level ground is one thing, snow all over the side of a mountain is another. Chaining up is a wet, miserable chore that I only do as a last resort!