Visual Demand of Driving and the Execution of Display-Intensive in-Vehicle Tasks

To gain insight as to when telematics can be distracting, 16 participants drove a simulator on roads with long curves of several different radii. Participants read electronic maps displayed in the center console while both parked and driving. In separate trials, the visual demand/workload of the same straight and curved sections was measured using the visual occlusion technique. Visual demand was correlated with inverse curve radius. As visual demand increased, driving performance declined. Participants made shorter glances at the display, made more of them, but waited longer between glances. Overall, task completion time increased when the task was performed while driving (versus while parked), except for short duration tasks (a single glance or under 3 seconds timed while parked), where task time decreased. While driving, task completion times were relatively unaffected by the driving workload.