Abstract

Distraction to driving activity can arise from inside or outside the vehicle. Passenger presence is believed to be one of the in-vehicle distractions. However, the existence of a passenger also crucial for drivers to minimize the monotony ambiance. In this study, the conversation between the passenger and driver will be the focus of discussion in determining the distraction phenomenon. This study uncovers the effect on the conversation to the driver's performance through laboratory simulation experiments. Three types of conditions were studied, i.e., driving alone with no passenger, driving with a passive passenger, and driving with an actively speaking passenger. Driver's alertness and performance while driving was monitored as the distraction effect on transportation safety. The alertness was indicated by the level of sleepiness obtained from ratio of α/β indicator using electroencephalograph measurement. The performance was monitored from accident frequency through the crash and near-crash indicator along the driving period. As expected, results showed that driving alone experienced the highest level of sleepiness than others. Surprisingly, the driving activity with an actively speaking passenger brought the highest number of accidents than others.