BMW Halbo concept: tiny motorcycle, hugely unsafe looking

The conceptual BMW Halbo is one tiny motorcycle. According to the designer, it only takes up half as much space as your average bike. It's got your standard wheel up front with a motor built into it, and the rear wheel is actually spherical, mounted on an arm that can move from side to side to help keep the whole thing balanced. That's good, because falling off this thing or getting in a collision...