In 3 lanes of traffic, when two cars in opposite lanes (ie: slow and fast) continuously switch places at high-speeds and come within 2 inches of hitting each other. Used by douchebags (or teens) to piss off all drivers in the immediate vicinity. Pulling this off requires great timing, patience and a LOT of balls. Typically seen in D.C., Chicago, Miami, and New York.
Seth: Dammit, why today?
Seth: Dave and Eric just did the devil's dance, and now there's a shitload of traffic thanks to the accident.