The difference here is when a car goes 1mph over the speed limit, the risk of a catastrophic crash is not substantially increased. Cars don't run the risk of losing control just because they go over the PSL which is often posted unusually low...
I'm not too sure about that. I had a conversation with an FAA rep about this. I live near an airport and ask the FAA if I could fly/inspect my amateur radio antenna, which is well below 100 feet. The answer was that I live in a zero grid and...