There are two ways to approach the problem. Either to be dogmatic about the wording or to be practical. I ended up with only one "is a vehicle" because I was enforcing it the way I would enforce a rule like that in real life, a practical rule. If you were being dogmatic about the wording you would undermine the likely intent of the sign by kicking people out of their wheelchairs and having to shoot down the ISS. Rigid adherence to bad (or even just badly worded) rules is its own form of tyranny, one that is even more insidious because it has a veneer of legitimacy. Much evil has been perpetrated throughout history by people who were "just following orders".
