Yes, defined terms are critical. As the exercise went on, I kept refining my mental model of what a “vehicle” was in the context of the park sign.

I eventually came up with a mental model that was something like “an artificially powered or mechanically advantaged means of conveyance or transport, especially one that creates negative externalities to other park goers inconsistent with typical use and enjoyment of public park space.” But that wasn’t absolute - the non-functional tank was, in my mind, quite obviously a vehicle, and so was prohibited. Someone at a higher pay grade is going to have to make an exception there. The skydiver - ehhh, it was a stretch to call him a vehicle, but by my heuristic he broke the sign’s rule.

>But that wasn’t absolute - the non-functional tank was, in my mind, quite obviously a vehicle, and so was prohibited.

Was, or is? The non-functional tank was a vehicle, but is currently a non-functional lump of steel and is thus no different to a statue. A statue is obviously not a vehicle, and a statue of a car is still not a vehicle.

How was the tank moved though?

Seems unlikely to have been pushed by people.

“Matthew, head of an organization of WWII veterans, puts a non-functioning WWII-era tank into the park as a war memorial.”

Not relevant. Assembled there and welded the moving parts. Doesn't matter. Is it a vehicle? No, it is a statue / art installation.

I had almost exactly the same definition, but interestingly I let the skydiver go free, and I figured the tank would be okay because it was stationary (and I think in my head I assumed someone else had allowed the memorial!)

In the end, I only banned the car and the boat, and the boat was only really on a technicality. In retrospect, I might have been being too lenient, but I think it had a lot to do with just the stuff that I wanted to see in the park, which is pretty interesting from a moderation perspective.

Horse is a fun one. I started to wonder does putting saddle and reins on one change things... So if you ride without them it is fine, but if you put those on it becomes a vehicle...

Travois is other one I kinda struggled... Just a a-frame even if you drag it in clearly is not one to me.

I don't think it really matters. The point I guess was that an ambulance or police car is obviously a vehicle, and obviously in the park. And yet enforcing this seemingly simple and logical rule becomes so absurd that some people would decide that a police car is not a vehicle just because it should be allowed in.

why is that the solution, and not that the police are allowed to break the rules?

The first page said to not make your own assumptions about the local laws, but to simply select if the rule as written has been violated.