Of course it isn't roadworthy. How would you panic stop, for instance? How reasonable is it to face the sky when speeding up or the ground when slowing down?
It look like riding a motorbike in a Big cage, and many motor bikes in a Big cage doing Circles shows . if it can go as fast 40km/h I am certainly sure any older folk will not want to go in and try. it does run like a air plane or a JET plane and go Upside down. it maybe good for health , the blood flow will bring more into the brain. I hope they could design a better HUB motor, better speed, better efficiency and that is all the Most members like to have. I think this machine might be useful for Movies, science friction may need one of these. One thing for sure, many people who ride this machine will ride Only once and no more riding riding again, it can give a person Into Sea sick ! watch the movie again and again.. did you feel abit giddy ?
The disturbing thing about designing a di-wheel vehicle is that you come to the conclusion that the easiest way to solve the stability problems is to add a wheel or two either in front or in back. But if you do that, you concede the di- design fails.
This particular project, EDWARD - Electric Diwheel With Active Rotation Damping, makes progress, but it still doesn't overcome the problems enough to be practical. I'm afraid if you want to limit the vehicle design to 2 wheels, a bicycle is the best configuration.