Caffeinated chewing gum as countermeasure to drivers' passive task-related fatigue caused by monotonous roadway

This study analyzed driver passive task-related fatigue caused by a monotonous environment and the effectiveness of caffeinated chewing gum as a countermeasure. Data collected by a driving simulator in the laboratory were used to measure changes in driving performance. A self-perceived measure of fatigue was also analyzed. Seventy-Two subjects were asked to drive for 70 min along a straight road after receiving one of the following substances (treatments): caffeinated chewing gum, a cup of coffee, or placebo chewing gum. The 72 subjects were subdivided into three groups of 24 each, and all participants were asked to take part in two driving sessions: one control drive without administration (no treatment) and one with administration (one of the treatments). The negative effects on driving performance of prolonged driving and the effectiveness of the standard deviation of the lateral position in representing worsening driving performance were demonstrated. This analysis indicated that intake of caffeine in the form of caffeinated chewing gum (100 mg caffeine) improved driving performance in less than 10 min. Drinking an ordinary cup of coffee (with the same caffeine content) did not improve driving performance in the same short time interval.