Flashing-lights Brake-dance
The result of a police officer pulling someone over for a traffic violation in Rhode Island. All the people in the state have to stop - not slow down, but fully stop - as they pass the vehicle that's been pulled over to see if it's someone they know. And thus, a single state trooper pulling over someone for speeding during rush hour can grind traffic on the interstate to a complete halt for more than fifteen minutes.
"My commute home should only take 20 minutes, but never takes less than an hour because of the Flashing-lights Brake-dance and the fact that people forget where the fuck Route 4 is every afternoon."