Driver eye glance behavior and performance with camera-based visibility systems versus mirrors

Objective Drivers' ability to extract visual information efficiently from mirrors or camera-based visibility systems impacts driving performance when carrying out maneuvers such as lane changes. The objective of the research was to compare drivers' eye gaze behavior and driving performance with mirrors versus camera-based visibility systems (i.e., CMS, or camera monitor system) to identify any differences and possible impacts on safety. Methods A test track study was conducted comparing drivers' eye gaze and lane change behavior when driving a vehicle equipped with outside mirrors versus a prototype CMS. Participants' opinions regarding usability and comfort in using mirrors versus the tested CMS were also obtained using a post-drive questionnaire. Results Study results were somewhat mixed but did demonstrate that with the tested CMS, participants took longer to pass a slower moving vehicle and maintained a greater resultant distance from the passed vehicle. Additionally, participants had a greater number of fixations to the CMS displays compared to the outside rearview mirrors. Results also found slight perceived advantages for the tested CMS in regard to ease of use, comfortability, and visibility. When asked to choose which rear visibility technology they would prefer to use in everyday driving, most participants preferred the outside rearview mirrors over the tested prototype CMS or having both systems. However, not all lane change and gaze metrics followed the same pattern. Conclusions In this study, participants' longer time to pass a slower moving vehicle, greater distance when passing a slower moving vehicle, greater number of fixations, and lower subjective ratings with the tested CMS may indicate difficulty in judging distances and focusing on the electronic image. This study provides preliminary findings that suggest differences in driving behavior exist between a single tested prototype CMS and outside rearview mirrors and is a foundational step toward evaluating whether these trends are consistent across different systems and overall implications for safe driving behavior.