Phantom Traffic Jams Explained

Joseph Stromberg explains the phantom traffic jam—that scourge of highway travel when everyone on the highway slows down for no apparent reason and then quickly accelerates to previous speeds.

1 minute read

November 25, 2014, 7:00 AM PST

By James Brasuell @CasualBrasuell


Stromberg focuses on the work of Benjamin Seibold, a mathematician at Temple University, and colleagues, who have developed a concept called the "jamiton" to explain the phenomenon.

Here's how Stromberg describes a jamiton: 

If there are enough cars on a highway, any minor disruptions to the flow of traffic can cause a self-reinforcing chain reaction: one car brakes slightly, and the ones behind it brake just a bit more to avoid hitting it, with the braking eventually amplifying until it produces a wave of stopped or slowed traffic.

The idea of jamitons raises additional questions about how much responsibility individual driving behavior impacts traffic flow. Stromberg also discusses a few of the options for preventing jamitons (spoiler: self-driving cars are one them).

Monday, November 24, 2014 in Vox

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