Cars Gone Wild: The Major Contributor to Unintended Acceleration in Automobiles is Pedal Error

Abstract

“Unintended-acceleration” automobile accidents typically begin when the driver first enters the car, starts the engine, and intends to press his/her right foot on the brake while shifting from Park to a drive gear (Drive or Reverse). The driver reports an unintended (uncommanded) full-throttle acceleration, coupled with a loss of braking, until the episode ends in a crash. Pedal misapplications – where the right foot contacts the accelerator instead of the brake that was intended – have been linked to these accidents (Schmidt, 1989, 1993) which, in the 1980s, were thought to occur only at the start of a driving cycle (and/or with the car in Park). But, in 1997, we identified over 200 pedal errors as the cause of accidents reported in the North Carolina database; these crashes occurred during the driving cycle (Schmidt et al., 1997), and/or with the vehicle in a gear other than Park. Our present work provides a more thorough analysis of these North Carolina Police Accident Reports from 1979 to 1995. The vast majority of pedal misapplications (over 92%) (a) occurred during the driving cycle, (b) were generally in “unhurried” conditions, and (c) were categorically separate from those events referred to as unintended-acceleration episodes at start-up. These ideas are explanatory for the recent (2009–2010) surge of unintended-acceleration reports, perhaps even suggesting that all of these crashes are caused by pedal errors, and that none of them are based on some vehicle defect(s).

Human Factors in Sudden Acceleration Incidents

“…These findings are consistent with findings that have utilized much older datasets (e.g., Perel, 1976;Schmidt & Young, 2010), and they more accurately represent the current-day drivers and passenger vehicles on the road.…”

Modeling Types of Pedal Applications Using a Driving Simulator

“…In this study we attempted to identify the foot trajectories that might be associated with pedal misapplications. The types of incorrect pedal applications were similar to those in other studies (Schmidt & Young, 2010;Tran et al, 2011;Young et al, 2011), but our study also included pedal types for correct applications (direct hit, hesitation, and corrected trajectory). The corrected pedal movements associated with hesitation and corrected trajectory should not lead to pedal misapplications but are of interest because delays in responses may present a safety concern in the real world depending on the criticality of a timely response (Doshi et al, 2012).…”

“…Rogers and Wierwille (1988) defined three types of pedal errors-serious, catch, and scuff-and they also suggested four potential sequences of these applications. Tran et al (2011), Schmidt and Young (2010), and Young, Heckman, and Kim (2011) considered two types: slip/miss and wrong pedal. Past studies provide definitions of pedal errors, but a complete examination of foot movements should also include types of correct pedal placements as well.…”

"Unintended Acceleration": Human Factors Engineering Issues and Solutions

“…But, later, we also identified over 200 pedal errors as the cause of crashes reported in the North Carolina database; these incidents occurred during the driving cycle (Schmidt et al, 1997;Schmidt & Young, 2010), and/or with the vehicle in a gear other than Park. Our present work provides a more thorough analysis of these North Carolina Police Accident Reports, and includes an analysis of over 3,750 reports from 1979 to 1995.…”