Investigating the effect of long trip on driving performance, eye blinks, and awareness of sleepiness among commercial drivers: A naturalistic driving test study

A total of 120 commercial drivers from four age groups participated in the expressway driving test in Shandong, China to perform 2, 3, and 4 h continuous driving tasks and collect the data on the driver's blinking, driving performance and self-reported level of sleepiness. Two-way repeated measures ANOVA was used to evaluate the effects of driving duration on the variation of the eye-blink behavior, driving performance and subjective feeling of sleepiness across the different age groups over the time periods tested. Additionally, Pearson product-moment correlation was used to quantify the association between the variations of the dependent variables. The results showed that there was significant difference between groups, significant effect over time and significant interaction between the age and driving duration in the variations of the driver’s blink frequency, blink duration, closure duration, speed perception, choice reaction time, number of incorrect action judgments and subjective level of sleepiness. However, a significant difference varied over time, but no effect of the interaction between groups and time were found in the variation of the driver’s attention allocation value. Furthermore, driver’s eye blink measures were more sensitive to sleepiness and older drivers were more likely to get sleepy in long distance driving.