Q: How to Best Alleviate a Traffic Jam on a Street? A: Close Access to Said Street

Ian — Tue, 30 Dec 2008 22:42:42 +0000

From the world of the counter intuitive, how to best manage flow within a network (think traffic, trains, manufacturing, process control, etc):

From the New York Times’ archives (in 1990!):

ON Earth Day this year, New York City’s Transportation Commissioner decided to close 42d Street, which as every New Yorker knows is always congested. “Many predicted it would be doomsday,” said the Commissioner, Lucius J. Riccio. “You didn’t need to be a rocket scientist or have a sophisticated computer queuing model to see that this could have been a major problem.”

But to everyone’s surprise, Earth Day generated no historic traffic jam. Traffic flow actually improved when 42d Street was closed.

Enter Braess’s paradox, which says that by restricting space in an urban area you can actually increase the flow of traffic, and, by implication, by adding extra capacity to a road network you can reduce overall performance. For the generalist, this means that by adding extra capacity to a network, the moving entities selfishly choose their route, possibly reducing overall performance.

This is exactly what happened when the George Washington Bridge introduced a second deck in 1962, thanks to the love him/hate him uber-planner of NYC, Robert Moses.

-Thanks. Futurismic

Urban Mapping Blog » urban planning

Q: How to Best Alleviate a Traffic Jam on a Street? A: Close Access to Said Street