I've seen the argument made that sprawl doesn't increase commuting times because jobs follow people to suburbs, and so suburbanites have shorter commute times than they would if their jobs were in the city.
But this article in today's Washington Post suggests otherwise.
The article notes that in metro DC, residents of DC and Arlington had the shortest commutes (29 and 26 minutes respectively). By contrast, residents of exurban Prince William County had the longest (41 minutes). Other suburbs had in-between commuting times.
What's going on?
First, Prince William is not one of the more job-rich suburbs. To the extent "job sprawl" benefits commuters, it benefits only the ones who live in the job-rich suburbs (in DC, Loudoun and Fairfax Counties more than Prince William). If you live in a less job-rich suburb, your commute might be longer than if you worked downtown.
Second, even if moving to a job-rich suburb to follow your job reduces your commute, other people in your household may still have a downtown job- which means the increase in that person's commute cancels out the decrease in yours.
For example, suppose my wife and I live downtown; my job is 8 miles out in suburbia and hers is a few yards away, so we have a total commute of 8 miles.
A year later, we move to suburbia, 2 miles from my job and 10 miles from my wife's downtown job. I am better off, but our total commute is 12 miles- far worse than when we lived downtown.
