Variability in Circumstances Underlying Pedal Errors: An Investigation Using the National Motor Vehicle Crash Causation Survey 2018-01-0493

Pedal errors have been widely reported as a leading cause of unintended acceleration (UA) incidents for several decades. Many governmental and scientific studies have attempted to characterize the rate of pedal errors leading to UA incidents using data from the North Carolina Crash Database. These data, however, are limited for various reasons, including the absence of an in-depth investigation of causal factors contributing to the accident. To further examine the rate of UA incidents related to pedal error, we utilized the National Motor Vehicle Crash Causation Survey (NMVCCS), a nationally representative sample of 5,471 crashes that occurred between 2005 and 2007. Using a targeted keyword search, we identified 48 potential pedal errors (30 driver-admitted), providing a national estimate of 17,919 pedal errors. We then investigated accident characteristics across these specific cases, including demographics of the drivers, vehicle characteristics, and pre-crash critical events. We found substantial variability across all of these conditions, indicating that pedal errors occur widely, irrespective of the aforementioned variables. We further found no differences in the characteristics of driver-admitted pedal errors, and other potential pedal errors. We also evaluated EDR data for those vehicles involved in a potential pedal error. EDR data were available from four vehicles, all of which were instances in which the driver did not recognize their pedal error. In these instances, EDR data confirmed that each of these drivers had their foot on the accelerator while they thought they were on the brake. The findings provide additional evidence that unintended acceleration and pedal error incidents do not result from a vehicle-based cause, but rather, result from driver error that can occur regardless of the vehicle driven, and without driver awareness.