Teaching doesn't depend directly on transportation, but you probably use transportation infrastructure to gain access to it.

Almost every aspect of modern civilization has indirect dependencies on infrastructure such as transportation. As James Burke explains in the first episode of "Connections", we've been living in a technology trap ever since the plow was invented.

However, most of these traps are indirect. The slack in the system converts a lot of total system failures into mere inconveniences. In the case of snow days, it's easy to plan to have a few unscheduled days off. It's a lot harder to plan for infrastructure failures when you depend on it directly.

I would imagine not in Minnesota? I think this is measure to limit traffic in places where snow is rare occurance and causes a spike in accidents.