The Effect of Caffeine on Drivers' Alertness and Situation

Traffic accidents are one of the leading causes of death in Indonesia, with human factors being the major contributor. One contributing factor is drowsiness, which can reduce drivers' alertness and situational awareness. Caffeine consumption is widely recognized as an effective method to enhance alertness and reduce drowsiness. This study aims to analyze the effect of caffeine consumption in a cup of coffee on drivers' alertness and SA through a driving simulation. This study involved 16 male students, with an average driving experience of 3.81 years. Alertness was measured using the Karolinska Sleepiness Scale and electroencephalography. SA was measured using the Quantitative Analysis of Situation Awareness method, which includes Actual Situation Awareness, bias, and Perceived Situation Awareness. The results indicate that caffeine consumption enhances objective alertness. Caffeine also enhances drivers' detection performance, as evidenced by increased detection sensitivity. Drivers who consumed caffeine had a higher hit rate and a lower false alarm rate, indicating improved accuracy in distinguishing relevant information while driving. Caffeine also influenced drivers' bias strategy, making participants more permissive in decision-making and decreasing bias value. However, no significant differences were found in PSA and subjective alertness.