This seems a fun direction of thought. So does it cease to become a vehicle as soon as someone sits in it, and resume its functionality as a vehicle as soon as it is abandoned?

So whether it's a vehicle depends on how well the person in it can walk? I don't know about that. I'd rather just give exceptions.

Sorry, I didn't mean it that way. I have older parents who can walk short distances but I'd rather they have the choice to use a wheelchair at an airport.

In general, no testing. Unless some people are being jackasses and doing something absurd like standing on wheelchairs jousting with long sticks holding up everyone in line.

What is your definition of need? If I need to meet friends in the park in five minutes I clearly need a car to get there in time. So the car would not be a vehicle in that case?

Does a wheelchair become a vehicle if somebody who _can_ walk without it sits in it? Does that mean everyone in wheelchairs must be harassed (to find out if they need it)?

Since the preamble mentioned this was a test of language literalness, before I answered the question, I looked up the definition of “vehicle”: “A means of carrying or transporting something” https://www.merriam-webster.com/dictionary/vehicle

While it might be uncommon to call a wheelchair a vehicle, it fits the literal definition. I don’t understand the ‘extension of the person’ rationale, you’re still using the word ‘wheelchair’, and it’s obviously a separate object from a person. How would that rationale differ if you were talking about cars? Can I argue a car is an extension of me as long as I’m using it while I need it?

It's a common sentiment among wheelchair users that the freedom they enable makes them feel like an extension of a person. In that context, for the purpose of the "vehicle" question, there's not much difference between a wheelchair, prosthetic leg, or eyeglasses.

I wouldn't say I'm entirely convinced, but it's at least convincing enough that I said that a wheelchair did not violate the "vehicle" rule. I can't define "vehicle" in a way that would satisfactorily justify that decision, but I'm comfortable with that.

The Merriam-Webster definition tends towards a vehicle being something with a power source (something where the power source is not manual/manus/human) capable of moving other things. That would include any sort of powered chair, but not be a problem for a standard wheelchair. Interestingly the Oxford American dictionary explicitly includes a cart as a primary example however, and Wikipedia’s primary example of a vehicle is a bike.