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.
Read full blog post here.