Generally, when it snows in Atlanta the roadways are still warm and the initial snows melts. Within minutes, the below-freezing air freezes the melted snow and in an hour's time the roads of an entire metro area are completely covered with ice, not snow.
It's similar to the phenomenon that causes Atlanta to have ice storms, where all outdoor surfaces, including power lines and tree limbs, become covered with 1/2" or more of solid ice.
I could drive in Boston and Chicago snow. I can't drive in Atlanta ice.
I can drive in New Jersey ice.