, Director, Mechanical Engineering
Older drivers represent the highest injury and fatality rate per 100 million miles driven. The disproportionate fatality risk is linked to several known factors, ranging from failure to yield to cognitive and visual limitations, to seatbelt use abstention to fragility. Through a series of focus groups, usability tests, and a controlled field test, a universally designed smartphone app called RoadCoach (designed to reduce risky driving behaviors, such as speeding and hard braking) was previously found to have high usability among older drivers. In this project, researchers conducted a field operational test of the app, which examined the baseline driving behavior (3 weeks) of 28 older drivers in Minnesota and Kansas, their driving behavior with RoadCoach feedback (6 weeks), and their driving behavior during a follow-up, no-feedback period (3 weeks). The results demonstrated marginal reductions in speeding behaviors while the app was functioning, but speed behaviors significantly increased after the feedback was discontinued compared to when it was active. Hard braking and stop sign violations were significantly reduced during feedback and post-feedback. Finally, satisfaction and trust were high among users, with drivers reporting that the app helped improve their attention and focus on the task of driving.