You're making the assumption that faster = more dangerous. Stopping distance, and pedestrian impact (as well as vehicle occupant safety) have at least as much to do with overall safety of driver and pedestrians as a car's theoretical top speed. A 500 may have a higher bhp/tonne than a hummer, but I imagine it takes less distance and time to stop a 500 from 30 than it would a Hummer, and I know which I'd rather be hit by (well, neither ideall, but you get the idea).
