Rubber necking is a US term which refers to the behavior where drivers slow down their cars to watch what goes on near the highway. Events range from gruesome car accidents to a police car stopped on the shoulder would cause traffic jam on both side of the road. A car with a flat tire on the side of a highway often causes as much slow down as a real accident would due to rubber necking. Traffic experts called this phenomenon phantom accident.

Some study showed that the average rush hour highway speed in Los Angeles is down to 18 mph, down from 35 mph five years ago. Given speed limit is set to 55 mph to 70 mph, traffic jam makes commuting a frustrating experience. The Americans burn 192 million gallons of gasoline each day. Rubber necking simply adds to the burden unnecessarily.