Simulator Study of Involuntary Driver Distraction under Different Perceptual Loads

Involuntary distraction, which occurs when driver attention is diverted unintentionally by irrelevant stimuli or events, is often overlooked in experimental studies. The present work explores how involuntary distraction affects individual drivers and whether varying perceptual load in the driving environment modulates involuntary distraction engagement. In a simulator experiment, variability in glance behavior toward irrelevant stimuli was observed among participants, and higher self-reported everyday distractibility scores using the Cognitive Failures Questionnaire were found to be associated with longer glances, but not the number of glances, toward the irrelevant stimuli. These relationships suggest that the Cognitive Failures Questionnaire scale may correlate better with the ability to disengage from a distraction than with the ability to suppress automatic attentional capture. The study also found delayed accelerator release times to lead vehicle braking events in the presence of irrelevant stimuli. The perceptual responses associated with the accelerator release times show that the delay occurred after participants glanced at the brake light, possibly indicating slower processing of information under distraction. Contrary to expectation, perceptual load, manipulated by the simulated road’s visual complexity, did not affect involuntary distraction engagement but directly affected driving performance. Overall, findings reveal potential safety concerns for involuntary driver distraction, but further work is necessary to understand how individuals with different attentional limitations are affected by this distraction type.