Beaker Hill: Boston's Roads Inefficient? No Way!

An urban legend claims that Boston's streets are haphazard because they trace the cow paths of the first European settlers. While that may be a bit of a stretch, it takes no leap of faith to say that our roadways make it difficult to drive...or walk. An article in the February issue of Scientific American adds some game theory to that assertion.

To no one's surprise, Michael Gastner of the Santa Fe Institute, along with colleagues Hyejin Youn and Hawoong Jeong from the Korea Advanced Institute of Science and Technology, found that the pattern of roads in Boston prolongs our daily commutes. On a sample trip from Harvard Square to Boston Common, the team named several routes which could be eliminated, including the stretch of Charles Street shown here. (They also found similar inefficiencies in New York and London, but who cares about those places, right?) The paper was published in Physical Review Letters last fall.

A large group of drivers will select routes based on the Nash equilibrium--the quickest possible trip based on the decisions of other drivers. However, the resulting "anarchy" doesn't maximize the network's overall efficiency. They describe this situation using "Braess's paradox," in which extra options bog down the system instead of speeding it up. Just something for the governor to consider with all that new gas tax money.

Below the fold: MIT Media Lab plays with fancy digital blocks (New Scientist), Mass. General doctors close incisions with lasers (Technology Review).