The Detroit Free Press talked to a number of engine experts who explain that with electronic systems controlling an engine’s acceleration, cell phone signals and microwave and radio towers could lead to unintended acceleration. This would happen on all cars, including past Toyotas not part of the recall that have been reported to accelerate out of control.
However, Toyota says its throttle-control system has fail-safes for such an occurrence and these parts would return a specific error when brought in for repair.
Since the most recent Toyota recall, many analysts are calling for Toyota and others to add “smart brake” technology that would allow depressing the brake pedal to override the throttle control, thus canceling any acceleration, intended or otherwise. Most European and luxury automakers and Nissan already use smart brake technology, but Ford, GM, Chrysler, Honda and Toyota do not.
Overall, unintended acceleration is fairly rare no matter the cause. Based on a Consumer Reports study of 2008 complaints to the National Highway Traffic Safety Administration, about one of every 50,000 Toyota, one of every 65,000 Ford and just one in every 500,000 GM vehicles experienced a problem.
Toyota's problem in other vehicles (Detroit Free Press)