When a driver accelerates through a yellow light knowing full well that shit will turn red before they get in the intersection. If done properly, the driver will end up running a red light.
Often, passengers will scream "FREE BIIIIIIRD!" for the duration of the intersection.
See also: Pennsylvania Left, Pittsburgh Left
"Dude I nearly died today, some jagoff was Free Birding an Intersection during rushour!"
"No way, was that the 3 car pileup at North and Main?"
"No, that guy was making a Pennsylvania Left."