Bump and run (auto racing)

Bump and run is a technique for passing used in stock car racing, related to the police PIT maneuver. Bump and run is never intentionally used in open-wheel racing due to the extremely high speeds and relative fragility of open-wheel race cars.

A trailing car intentionally bumps the car in front of it. The bump sometimes causes the lead car's rear tires to momentarily lose traction. The driver of the lead car is forced to correct his steering, slow down, or at least stop accelerating to regain traction and/or car attitude. The trailing driver positions to pass the leading car before the next corner. Bump and run is often done after coming off a corner. It is much more dangerous when done in the middle of a corner because both cars are already loose.

A gentle tap is what is required most of the time. A stronger bump might result in the lead and/or the trailing car spinning out of control, and possibly leading to a multi-car crash.

Car of Tomorrow

NASCAR's newly redesigned car (dubbed the Car of Tomorrow) is expected to hinder the effect of bump and run. The rear bumpers on the cars have been lowered, while the front bumper has been raised. In this configuration, when a trailing car hits a car in the back, the contact is square, and the leading cars rear wheels are not lifted off the track. ^[1]

References

Matt Crossman (April 1, 2007). "The art of the bump and run". Sporting News. Retrieved 2007-04-29.