Risk and Driver Behavior with Adjustable Pedals

Recently, various automotive manufacturers have developed and installed adjustable pedal systems that allow the pedal package (accelerator, brake, and clutch) to be moved in unison toward or away from a driver's standard (and historically fixed) position. To determine if there was a possible danger associated with adjusting or manipulating the pedals while operating the vehicle, we engaged in two separate investigations. First, we evaluated the potential risk associated with adjusting or manipulating in-vehicle controls, such as tuning the radio or moving the seat position, for an estimate of how the operation of similar devices influences vehicle safety. Our analysis of accident data from North Carolina shows that about 60 accidents per year occur while drivers are adjusting a radio, with only a few annual accidents tied to other in-vehicle controls such as wipers, mirrors, and heaters. Based on these findings, accidents associated with pedal location adjustment are likely to be extremely rare. Second, we completed a fixed-base simulator study to evaluate how the manipulation of the adjustable pedal system influenced driver behavior and vehicle control. Changes in pedal position had no detectable influence on brake reaction times. Adjusting pedal position (on demand from the experimenter) had only a very small effect on measures of speed, lane position, and brake reaction time, in all cases within the range of effects found with operation of radios, cell phones, and seat controls. Findings from this aspect of our work add further confidence to the prediction of low accident risk for pedal location adjustment. Implications for driver behavior and vehicle safety are discussed.