Braess's Paradox: A Puzzler from Applied Network Analysis

In late 1990, the New York Times carried a story concerning traffic flow, which was not the usual bad news of gridlock and stationary fast-trackers; rather, it concerned an anticipated problem that never developed. City officials had decided to close 42nd St. in Manhattan as part of the Earth Day observance in early 1990. A major east-west artery, 42nd St. is perpetually clogged with traffic. Many had expressed concern that this congestion would spread to other areas, many already congested themselves, while 42nd St. was closed. Perhaps a major traffic jam, even by Big Apple standards, was in store.