Unfortunately not all of the kids in the county live on major roads. There are school bus routes where the streets are so small and hazardous on either side that the school buses can't even turn around in good weather and have to back out of the street to get back onto a main road. If some of those roads are heavily woody and therefore shady you are going to get quite a bit of ice that you wouldn't see on the more heavily traveled major thoroughfares.
The school systems typically build in some days when they can into the school schedule because stuff happens. 2 hours off of school to make sure that the sun comes out and warms up potentially frozen roads is not going to be the difference between little Johnny getting into Harvard or not. Worst case scenario some time needs to be made up at the end of the year or over a break when the weather is better. Safety should come first because you can always make up time.
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