Taxi drivers claims that they can drive you from point a to point b.
So what's the difference??
It's like comparing an experienced driver (taxi or not) and a student driver. I'd sleep with an experienced driver driving but I wouldn't even think about sleeping if I am being driven by a student driver.
An experienced driver and an amateur driver are both driver. But you will trust the experienced one more.
> capable of travelling without input from a human operator, by means of computer systems working in conjunction with on-board sensors.
A taxi clearly does not match this definition, since it has a human operator.
I assume we are not just making up words ourselves, because that would be meaningless. What definition are you referring to that would match your usage?