Personal transportation devices are diversifying in form and price. Regulating that this way seems senseless.
Of course, the present form of automobiles circulating on public roads and highways should be subject to expert inspection every two years. They are just too big and powerful for any other approach. That should be done in an objective, not-for-profit setting. Just as auto insurance should be part of registration of a vehicle, we all have to know that everyone is playing fairly on even ground when safety in circulating is concerned.