Our neighborhood in the northeast US does the same (minus the hard prohibition against parents going with them). Our 5 and 9 year old walk to school daily, usually picking up the neighbors' kids (6, 6, 10, 9, 7, 7) along the way. If we happen to be free sometimes an adult will walk with them, sometimes we start walking with them and then stop for coffee with a neighbor while the kids continue on, sometimes they go by themselves.

I can't imagine living somewhere where that was prohibited.