How younger and older drivers’ steering reversals change with cognitive distraction during both day and night-time driving

Distracted driving is known to contribute to undesirable driving outcomes, including near misses and crashes. While the adverse effects of driver distraction are well recognised, the modality of distraction and individual and environmental factors also matter. With this in mind, this study explored how age, lighting conditions, a DetectionResponse Task (DRT) and cognitive load affect vehicle control, investigating the effects of steering wheel reversal rate (SWRR). A driving simulator study was conducted with 20 younger (MAge = 22.60, SDAge = 1.22) and 17 older (MAge = 65.82, SDAge = 3.78) drivers. Drivers completed two experimental drives (day-time and night-time), during which they were also required to complete the n-back and DRT tasks. The effect of these conditions on SWRR was examined separately for both 0.5° and 2.5° reversals. Results show an inverse change in night-time driving for both small and large reversal rates, with an increase for older drivers and a decrease for younger drivers compared to day-time driving. In addition, cognitive load was associated with fewer large reversals in the absence of DRT, whereas the presence of DRT resulted in an increase in both small and large steering reversals. The findings enhance our understanding of how driver distraction and other individual and environmental factors affect steering control.