This study investigated the changes in electroencephalography (EEG) activity in train drivers during a monotonous train-driving session. Four combinations of EEG activities were also compared to investigate the difference in performance of these equations. The four equations tested were equation 1 (θ/β), equation 2 (θ/(α+β)), equation 3 ((θ+α)/β), and equation 4 ((θ+α)/(α+β)). A total of fifty male train drivers were recruited to perform a 30-min monotonous train-driving task while 2-channels of EEG (frontal and temporal) were recorded. At the frontal site, significant differences were found for theta (p=0.045) and alpha (0.0001) activities, and at the temporal site, significant differences were found for delta (p=0.007) and theta (0.01) activities. For the average of frontal and temporal site activities, significant differences were found for delta (p=0.004), theta (p=0.001), and beta (p=0.048). Significant difference were found for temporal site for equation 1 (θ/β) (p=0.04), and equation 4 ((θ+α)/(α+β)) (p=0.02), and for the average of frontal and temporal site activities, significant differences were found for all four equations (equation 1 (p=0.001), equation 2 (p=0.006), equation 3 (p=0.04), and equation 4 (p=0.002)). These findings can be utilised as a potential fatigue indicator.