I do not think dogs at the bus stop are a good idea. At the beginning of the school year, my neighbor brought her dog to the bus stop. It is a German Shepherd and I would have said it was one of the best trained dogs I'd ever seen. It routinely walks without a leash and minds it's owner (although she was leashed at the bus stop). She has played with the neighborhood kids a lot (she likes kids). They take the dog nearly everywhere (it's used to being out and around people.
Our bus stop serves two neighborhoods and there are quite a few kids and parents. It all happened so fast that nobody is exactly sure what happened. The dog was leashed and in a sit next to its owner. Some kids were playing behind the dog and others were standing around. Something happened I'm not sure if a kid stepped on her tail, or someone grabbed her from behind, or what--but something happened and the dog snapped at the girl standing next to it. That girl wasn't doing anything, but the dog got her arm and broke the skin.
I am confident that one of the kids behind did *something* but nobody saw exactly what and none of the kids would say either. But I think it was lucky that the girl who was bitten was from our neighborhood and her parents knew what a "nice dog" she normally is. The mom confirmed that the dog had it's shots and cleaned up her child...but if it had been someone else who'd reported a vicious dog, it could have been bad news for the owner and the dog. Just not worth it, in my opinion. Even if your dog is nice and well trained, if they feel threatened, all bets are off.