Driving simulator experiments to study drowsiness: A systematic review

<b>Objective:</b> The National Highway Traffic Safety Administration in the USA estimated that the effects of drowsiness while driving led to approximately 72,000 crashes, 44,000 injuries, and 800 deaths in 2013. Keeping this in mind, the risk and injuries of drowsy driving remain a major safety issue that clearly needs to be studied. Our purpose was to conduct a systematic review of international literature including studies on driving behavior associated to drowsy and fatigued drivers. The research focused on the prediction and effects of drowsiness, and particularly on studies based on driving in simulated environments. Additionally, we searched for studies related to driving simulators, in general, to better understand the tool’s efficacy and its advantages and disadvantages. <b>Methods:</b> This review was made in accordance with PRISMA statement guidelines. After conducting in-depth research in targeted databases, 23 studies met the inclusion criteria; the papers were analyzed regarding the type of experiment and procedures and driving performance of 690 participants was studied. <b>Results:</b> Studies revealed that drowsiness have effects on driving performance and these effects become more relevant with time-on-task and in monotonous scenarios and landscapes. In addition, some documents include validations of several technologies to detect and predict sleepiness. <b>Conclusions:</b> Overall, we can conclude that drowsiness and fatigue impair driving performance, resulting in drivers who are more exposed to risky situations.