Lord Bracknell
On fire
What about mobility scooters and electric bikes? I have also seen segways with handlebars and power assisted scooters and skateboards in my time as well.
Mobility Scooters that are capable of travelling between 4 and 8 mph have to be registered with the DVLA, before they can be used on the roads. If the maximum speed is 4 mph or less, or they travel at 4 mph or less, they can't be used on the road.
Electric bikes (or tandems or trikes) have to comply with a whole set of Type Approval and Use regulations and can only be driven on the road by cyclists over the age of 14.