The GOOD 100: Fewer Streets

Blockade Parade

How closing streets can actually reduce traffic

As the city of Vancouver prepared to convert a car lane on the busy Burrard Bridge into a bike path last summer, some imagined impending anarchy. At the time, one cabbie, Jatinder Nijjar, predicted, "It is going to be chaos." In fact, the trial-and the traffic-has run smoothly so far.

Nijjar might have had different expectations had he read "The Price of Anarchy in Transportation Networks," a paper published in the journal Physical Review Letters in August, 2008. The paper's authors, two Korean physicists and a researcher at the Santa Fe Institute in New Mexico, showed that closing certain streets in Boston, London, and New York could actually reduce traffic. This counterintuitive result can be explained by Braess's paradox, a mathematical concept that describes how, when individual drivers make the decision to take the quickest route, they all try to squeeze onto the path they perceive as being fastest in the short term, and everyone's commute is longer than it has to be. Providing fewer driving options turns out to mean that commuters spread out their commutes more equitably among the routes available, making the average commute shorter for everyone-not to mention creating a more pleasant civic space.