How Long Can a Driver Look? Exploring Time Thresholds to Evaluate Head-up Display Imagery

Abstract

Currently, the visual demand incurred by vehicle displays is evaluated using time criteria (such as those provided by NHTSA). This 60-participant driving simulator study investigated to what extent glance time criteria applies to Head-up Display (HUD) imagery, considering 48 locations across the windshield (and 3 in-vehicle display positions). Participants were required to make a long controlled continuous glance to a sample of these locations. Consequently, the time at which lateral/longitudinal unsafe driving occurred (e.g. deviating out of lane, unacceptable time to collision) could then be assessed. Using the selected measures, the results suggest that drivers are able to maintain driving performance for longer than recommended NHTSA guidelines for in-vehicle displays whilst engaging with HUD imagery in various locations. Importantly, the data from this study provides initial maps for designers highlighting the visual demand implications of HUD imagery across the windshield.