I always go inside and ask, even if I see other RV's parked on the lot. Why? Not because I am a particularly rule abiding person. The reason I ask is that there is an often repeated story on the Internet about a scam being operated between some local officials and a towing company in which the RV is "Fined" over one hundred dollars for violating some obscure city ordinance. It sounds more like a shakedown and probably not legal, but who is going to fight city hall when it is the locals doing the shaking?
I do not ask the cart kid, but an actual manager. I sleep better knowing the next clang I hear is not the tow truck attaching his hook.