That doesn't make any sense. The cars compressed the snow into a layer of ice.
Not once in the article was the word "salt" mentioned and only once in the comments where a guy said they didn't need salt trucks. I guess they just sit around and wait until it melts.
Yes, it does make sense and that's what often happens with snow in the South. The asphalt and concrete retains heat longer than the soil and grass, etc. Often the snow will fall and stick and accumulate on the open ground and grass, but the highways will appear clear because the warmer asphalt melts the snow for a time until the asphalt cools down to freezing.
At that point, the water from the melted snow on the highway freezes and forms a layer of ice. And there is a difference between packed, dry snow and a sheet of ice. That layer of ice remains and the new snow is stirred and packed on top the ice, but since there's usually only a few inches of snow, we just have a half-inch to an inch or mixed ice and packed snow on the road. - And then, at times, that mixture might partially melt and then refreeze into a thicker sheet of ice. And then it will all be gone, usually within one or two days. The roads are totally clear where I live now, and were around noon today.
Herman Cain or whoever described that is correct for many southern, problem snowstorms. And that's what happened this week, in front of my house and elsewhere.
What's a 'salt truck'?
Atlanta doesn’t need salt trucks - until they need them. When it snows every 10 or more years in a place, buying and maintaining such capabilities is a big waste of taxpayer money.
But sometimes it bites a little...
There was a great comment by a FReeper in one of the Atlanta threads along the lines that when he moved from up North, his neighbor saw his snow shovel and said “we don’t shovel snow - we wait for it to melt.” The FReeper said this was true, and it largely is.