Understanding the Automotive Pedal Usage and Foot Movement Characteristics of Older Drivers

This study was driven by the prevalence of older drivers’ overrepresentation in crashes caused by pedal application errors. Previous research has shown tasks prone to pedal errors, which include emergency braking, parking lot maneuvers and reaching out of the driver’s window. However, pedal usage characteristics of older drivers while performing on-road driving tasks are unknown. The objective of this research was to understand pedal usage characteristics of older drivers during on-road driving tasks in an instrumented vehicle. Twenty-six drivers over the age of 60 completed 10 stopping tasks as the baseline for stopping performance, a startle-braking task, two forward parking tasks and two reaching out of the vehicle tasks. Results for this instrumented vehicle study showed significantly positive correlations between stature and the percent of foot pivoting, and between shoe length and percent of foot pivoting in the baseline stopping tasks. Drivers were more likely to use foot lifting in emergency braking than in the baseline tasks. Foot movement strategy did not affect lateral foot placement in either the baseline stopping tasks or the startle-braking task. When reaching out, lateral foot placement on the brake biased rightward, compared with the lateral foot placement prior to reaching out. Approaching a gated access or parking garage space did not significantly slow down a driver’s foot transfer from the accelerator to the brake. To validate the findings, future work should examine pedal usage characteristics in a more controlled environment, using a larger sample size that would include younger drivers.