Traffic Jam on a Petri Dish

10:46 AM EDT on March 11, 2008

This one comes to Streetsblog via the Sightline Institute's Daily Score, a blog covering environmental issues in the Pacific Northwest.

Why do traffic jams materialize for no apparent reason? In an effort to answer that question, here's a surprisingly simple experiment cooked up in Japan by the University of Nagoya's "Mathematical Society of Traffic Flow:"

If you are the kind of transportation geek who finds this sort of thing fascinating then you'll also really love this web-based traffic simulator out of Germany. But "prepare to lose your afternoon," says Sightline's Brad Plumer:

A few years back I wasted hour after hour playingwith the java settings, and watching "traffic" jams materialize andmelt -- just like in real life. My favorite quirk: for onelane-narrowing scenario, I could make traffic flow along beautifully at40 miles per hour, but seize up like glue at either 20 mph or 60 mph. Another fave (and very relevant to congestion pricing debates) wasletting traffic flow along smoothly at, say 1,400 "cars" per hour, andthen increasing traffic volumes to 1,500 -- and watching the trafficjam crystallize within moments.

Aaron Naparstek

AARON NAPARSTEK is the founder and former editor-in-chief of Streetsblog. Based in Brooklyn, New York, Naparsteks journalism, advocacy and community organizing work has been instrumental in growing the bicycle network, removing motor vehicles from parks, and developing new public plazas, car-free streets and life-saving traffic-calming measures across all five boroughs. Naparstek is the author of "Honku: The Zen Antidote for Road Rage" (Villard, 2003), a book of humorous haiku poetry inspired by the endless motorist sociopathy observed from his apartment window. Prior to launching Streetsblog, Naparstek worked as an interactive media producer, pioneering some of the Web's first music web sites, online communities, live webcasts and social networking services. Naparstek is currently in Cambridge with his wife and two young sons where he is enjoying a Loeb Fellowship at Harvard University's Graduate School of Design. He has a master's degree from Columbia University's Graduate School of Journalism and a bachelor's degree from Washington University in St. Louis, Missouri. Naparstek is a co-founder of the Park Slope Neighbors community group and the Grand Army Plaza Coalition. You can find more of his work here: http://www.naparstek.com.

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