Eyes-free In-vehicle Gesture Controls: Auditory-only Displays Reduced Visual Distraction and Workload

Visual distractions increase crash risk while driving. Our research focuses on creating and evaluating an air gesture control system that is less visually demanding than current infotainment systems. We completed a within-subjects experiment with 24 participants, each of whom completed a simulated drive while using six different prototypes, in turn. The primary research questions were the influence of combinations of visual and auditory displays (visual, visual/auditory, auditory) and control orientation (vertical vs horizontal). We recorded lane departures, eye glance behavior, secondary task performance, and driver workload. Results demonstrated that for lane departures all prototypes performed comparably, with the auditory-only showing a strong tendency of improvements. A deeper look illustrated a tradeoff between eyes-on-road time and secondary task completion time for the auditory-only display - the safest but slowest among the six prototypes. The auditory-only also reduced overall workload. Control orientation showed only small subjective effect in favor of vertical controls.