Until about 100 years ago, almost every city in the world was laid out on a rectangular grid. New York City and Washington D.C. are prototypical U.S. examples; most European capitals are also. Starting around 1930 however, city designers abandoned dense urban grids for garden communities with meandering streets and cul-de-sacs. These new cul-de-sac neighborhoods were thought to be safer and more private alternatives to the pollution, poverty and overcrowding of traditional cities.
Most of us still think this way but research shows that this belief is wrong. Garrick and Marshall compiled data on 230K car accidents over 11 years in 24 medium-sized California cities. All cities had a similar number of accidents but those built on grids had a much lower percentage of deadly ones. In fact, fatal crashes were >270% higher in the cul-de-sac communities than the ones built on grids.
A lot of people feel that they want to live in a cul-de-sac, they feel like it’s a safer place to be. The reality is yes, you’re safer – if you never leave your cul-de-sac. But if you actually move around town like a normal person, your town as a whole is much more dangerous.
The researchers also found that people who live in cul-de-sac neighborhoods drive about 18% more than people who live in dense grids. This is not surprising since it’s a lot harder to walk to the grocery store, the post office or to a restaurant. I’ve noticed my own annual driving mileage has increased since I moved from a grid neighborhood to a cul-de-sac one. In some sense, the communities were built for cars, not for people.
Increased driving leads to higher costs which might help to explain why U.S. foreclosures have been more common in suburbs than in urban areas. In addition, although this isn’t a formal study, residents who have less opportunity to walk seem to be less healthy than their urban counterparts.
Cul-de-sac communities force us to drive more, are less safe, and may even make us less healthy. Why do we all want to live there?