"some idiot could do something to blow himself up. "
I didn't miss the minor theme of private versus public property, but what I was pointing out had more to do with your own safety concerns. In this case, public safety: You don't want some idiot able to mess with traffic signals and kill people with amusing tricks like green in all directions. Yet, in opposition to that reasonable concern is the nearly as valid concern for rapid and universal access by authorized personnel; and thus solutions like proprietary keys and Torq bits.