Why do so few people live within walking--or at least bicycling--distance from where they work?

I've asked a lot of people this question and gotten a lot of different answers. Some people want big houses, others big lawns. A lot of people think--for reasons that they can't really articulate--that suburbs are the right place to raise kids. But one reason that you hear a lot is that people want to live somewhere safe--a low-crime area.

The fact is, that's not a good reason to live a long way away from where you work, because a long commute is more dangerous than living in a dangerous neighborhood.

It's one of those odd quirks of the way people's brains work that people don't recognize this immediately. People drive all the time, so driving seems safe. Violent crime, on the other hand, is rare, making it seem like a bigger danger than it is. A quick check of the statistics, though, tells the story.

The most dangerous neighborhood I could find in a quick search on the internet was census tract 440100 in south-central Chicago. According to the Chicago police department, there have been 225 violent crimes, including 5 murders, this year in this neighborhood, which has a population of 9324.

So, that's 5 murders per 9324 people per 365 days which comes to 0.00000147 murders per person per day.

According to the Bureau of Transportation Statistics, there are 100 injuries, including 1.5 deaths per 100 million vehicle miles, which works out to 0.000000015 traffic fatalities per mile driven.

That's all the information we need to find the commute that's as dangerous as living in the most dangerous neighborhood in Chicago: 49 miles (a 98 mile round trip).

Granted that's a long commute. On the other hand, that assumes that there's a zero percent chance of being murdered in whatever neighborhood you do live in, which is at least a little optimistic.

Of course, there are other scary crimes that can happen in dangerous neighborhoods, but if you compare all violent crimes to all traffic injuries, the long commutes come out even worse. If your commute is 33 miles each way, you can expect to be injured in a traffic accident about as often as you'd be a victim of a violent crime living in the most dangerous neighborhood in Chicago.

None of this is to suggest that you ought to live in a dangerous neighborhood. Often just moving a few blocks can make a big difference. Move a few blocks west to census tract 440200 (where there's been 4 murders in the past year and 167 violent crimes) and the equivalently dangerous commute drops to 24 miles each way. If you're driving further than that because you want to live in a safe neighborhood, either there's blood running in the streets or you haven't done the math.