Biggest problem: personal cars are built for safe freeway travel at 60-80mph. So they're heavy as hell (often 4000+ lbs), and physically large. But incredibly

Biggest problem: personal cars are built for safe freeway travel at 60-80mph. So they're heavy as hell (often 4000+ lbs), and physically large. But incredibly wasteful in the city, on 0-35mph urban roads clogged with bikes and peds. Low speed/neighborhood electric vehicles might point the way.