Hmm, what is the fastest speed a mobility scooter is allowed to go?
4mph for the "pavement" variety ~ needs no licence, tax or insurance
8mph for the "road" variety ~ needs insurance and must have lights, indicators etc.
And yes I realise the question was asked tongue in cheek but since I have two of them I thought I'd answer it anyway.
My lightweight one fits the car boot with ease, has a range of 7 miles per charge and is adequate.
The second and much heavier one is Italian (yes it has a reverse but only one). That one has a range of 20 miles per charge and travels at 6mph if I want it to. That's the one I use when the boys and I go out ~ them on their bikes.