The typical argument against density and infill is that it will bring traffic to a grinding halt.  But if density is done right, it can actually reduce overall travel times.  Why?  Because jobs are co-located with housing, and people can access more jobs or move to jobs more easily.

Eric Jaffe at CityLabs took a good look at the issue:

What is a little surprising is that even as cities get larger, life in them doesn’t necessarily grind to a halt. Sure, it can sometimes feel like that’s the case when you’re stuck in rush-hour gridlock. But while traffic congestion may be a personal annoyance, it’s also a broad indication of a healthy economy. If it’s easy for you to drive right downtown at 9 a.m. on a Monday, there probably isn’t much downtown to do.

Take the comparative example of New York and Chicago circa 2000. New York at that time had more than twice Chicago’s population and nearly twice the jobs: 7.6 million to 3.9 million. But it didn’t have twice the commute trouble. On the contrary, workers could reach 85 percent more jobs in New York than in Chicago within an hour (6.2 to 3.6 million) and 82 percent more jobs within a half hour (3.7 to 2 million).

This is why opposition to density can be so short-sighted and parochial. Because a few neighbors don’t like a big project going in nearby, they end up pushing out development to the fringes and requiring more people to spend more of their lives and incomes traveling to or from work.

It’s a dynamic that has been so destructive to places like California, in terms of the economy, environment and quality-of-life.