Estimation of driver vigilance level for various cognitive distractions when drivers use advanced driving assistance functions

Abstract

According to the World Health Organization report, 162 countries have enacted legislation prohibiting distracted driving. The regulations on distracted driving mainly restrict physical and visual distractions related to the use of handheld phones, with less restrictions on cognitive distractions. However, it is not yet clear which cognitive distracted driving behaviors may lead to significant decrease in driver vigilance. The purpose of this study is to assess how different cognitive distractions affect driver vigilance when drivers use advanced driving assistance functions in a monotonous driving highway environment. Using a driving simulator and external devices, the multi-dimensional including mental workload, vigilance reaction time and accuracy, eye movement data were collected from 31 participants. Cognitive distractions types included visual-manual-cognitive distraction tasks, auditory-cognitive distraction tasks and a no-distraction task. Three Multiple Criteria Decision-Making methods were used to evaluate the driver vigilance level during different types of cognitive distractions. The results indicate that participants exhibited lower vigilance levels during visual-manual-cognitive distraction tasks (L3 and L2) compared to auditory-cognitive distraction tasks (L2 and L1) and the no-distraction task (L1). This was due to the nature of the visual-manual-cognitive tasks, such as the message-sending task, which involve both language generation and comprehension, requiring higher levels of brain activation and attention resources. Therefore, visual-manual-cognitive distraction tasks should be limited when drivers use advanced driving assistance functions. In contrast, simple auditory-cognitive distractions, such as listening to new tasks, helped drivers remain alert and maintained vigilance levels comparable to the no-distraction task. This indicates that the auditory-cognitive distractions that involve language comprehension can assist drivers in maintaining an appropriate stimulation level, thereby preventing a decrease in vigilance associated with mind-wandering. Therefore, auditory-cognitive distractions involving language comprehension can be permitted in simple driving environments. As the vigilance level was lower at moderate level for auditory-cognitive involving working memory(1-back), it is recommended to warn this type of distraction.