This is the answer, but it opens up another line of questioning: do we force people to live in dense urban areas? Sometimes I wonder if pro mass-transit commenters (I'm pro mass transit, FWIW) have ever lived outside of a major metro. There are so many places where people live where mass transit is never going to be viable in way that replaces the car. Who gets to decide when/if we invalidate their way of living? Maybe I'm not seeing all the angles here.