Does closing roads cut delays?(Read article summary)
A recent study has found that closing off certain streets can actually improve traffic congestion.
John Nordell / The Christian Science Monitor /FILE
File this one under "intensely counterintuitive." A recent study has found that closing off certain streets can actually relieve traffic congestion.
Using Google Maps, a trio of scientists – Hyejin Youn and Hawoong Jeong, of the Korea Advanced Institute of Science and Technology, and Michael Gastner, of the Santa Fe Institute – looked at traffic routes in Boston, New York, and London. Their paper, titled "The Price of Anarchy in Transportation Networks: Efficiency and Optimality Control" [PDF] and published in the journal Physical Review Letters, found that, when individual drivers seek the quickest route, they sometimes end up slowing things down for everybody. [Editor's note: An earlier version misstated the name of the journal.]
It all hinges on something called Braess's Paradox (and yes, I appreciate the irony of a Wikipedia entry that challenges the wisdom of crowds), which states that adding capacity to a network in which all the moving entities rationally seek the most efficient route can sometimes reduce the network's overall efficiency.