Unintended acceleration may mean that a car's throttle is stuck in an open position or that there is a problem with the gas pedal. Mistakes also lead drivers to believe their cars are accelerating on their own.
Some are concerned that drive-by-wire designs make cars vulnerable to programming errors that might lead to sudden acceleration. However, studies have revealed that driver errors are common in reported incidents, and no software errors have been conclusively linked to unintended acceleration incidents. In the 1980s, Audi drivers reported cases of sudden acceleration. Government agencies, however, found no mechanical problems and placed the blame on driver mistakes.