Is There a Gap in Traffic Devices?

There are many ways, every day, which can hardly be done by other means than by individual devices with an engine. Why not establish cars which have the weight of 400 kilos, with one seat, or as a maximum, to where people can drive to work, through their leisure things and so on? So if cars lose 80 % of their weight, they need much fewer energy, and it's still a car, but rather like a motor bak with a support around it. This is really a gap in traffic devices which should be filled somewhere in the world. Yes, maybe in china. They'll do that first. We'll see. That's crazyt imean