Private cars are a horribly inefficient way to move people. A lane of traffic can move about 1500 people per hour at most (traffic at full speed, every car tota

Private cars are a horribly inefficient way to move people. A lane of traffic can move about 1500 people per hour at most (traffic at full speed, every car totally full), in real life its more like 800 people per hour. Compare that to 10,000-25,000 people per hour on a commuter train. By focusing development around cars, American cities actually decrease the practical size of the metropolitan area.