Comment by nathan_compton

It might be a problem, but it is also an inescapable part of the human condition because, at the end of the day, rules are imaginary and all that really exist are human actions. It is pretty hopeless to complain about rules from this point of view.

Assumption of intent is critical to pretty much all social functioning. In this particular case, I think its outrageously reasonable to assume that if some unusual circumstance were to prevail in the park relevant to the definition of vehicle, the sign would explicitly indicate it. And that, without further clarification, the obvious answer is the one intended.