The Effects of Distraction Type and Difficulty on Older Drivers’ Performance and Behaviour: Visual vs. Cognitive

Abstract

Driver distraction is an important contributing factor to increase crash risks. The effect of secondary task engagement may vary by interaction types and driver age. Thus, it is essential to understand the impacts of distraction type and age on driving performance for improving the safety of in-vehicle secondary task design. This paper aims to assess potential risks induced by visual and auditory secondary tasks while driving. Thirty drivers, consisted of fifteen younger drivers aged 25 ∼ 35 and fifteen older aged 60 ∼ 69, were recruited and asked to drive in a simulator. They conducted two driving sessions, one for visually distracted driving and the other for cognitive distraction. The order in which secondary tasks were presented was counter-balanced. Driving performance and behaviour data were collected continuously using multiple measurement devices for vehicle speed, lane position, electrocardiogram, and gaze pattern. Differences in younger and older drivers’ performance while conducting the secondary tasks were compared. The result indicated that the effect of interaction types, i.e., visual and auditory, on older drivers’ performance was significant. More difficult secondary task creates greater age difference in driving performance. However, eye movement and physiological response were not significantly different between younger and older drivers. This result could suggest older drivers’ lower risk awareness of cognitive distraction.