Unintended Acceleration: A Review of Human Factors Contributions

Abstract

The evidence is reviewed for a human factors explanation of the phenomenon of unintended acceleration, whereby at the start of a driving cycle an operator experiences full, unexpected acceleration for as long as 12 s with an apparently complete failure of the braking system, often leading to an accident. There is strong support for the view that the right foot contacts the accelerator even though the driver fully intended to press the brake because of inconsistency in foot trajectory generated by spinal- or muscle-level variability. There is considerable evidence that the variable, inconsistent processes that generate muscular forces and their timing are the source of these errors. Issues related to the reasons the driver is not aware of such errors and why they can persist for so long are reviewed. In view of this evidence, future examinations of this problem should be directed toward a fuller understanding of motor control processes in pedal operation.