ABSTRACT
The use of a hand-held cell phone by a driver while driving in Japan has been prohibited since 1999. However, the number of traffic violations related to the using of hand-held cell phones in 2008 was about one million two hundred thousand, and it has been increasing each year. The aim of this study is to examine impacts of cell phone conversations on the driving performance of fatigued drivers. Ten male students performed No-task (NT) and conversation (cognitive tasks) with handsfree (HF) and hand-held (HH) cell phones while driving in city traffic in which the maximum speed limit is 40km/h. Each participant was given a practice run on a monotonous road for more than 50 min in order to become familiar with the driving simulator and to induce fatigue while driving. Reaction time to step on brake in response to pop-up event was significantly slower in HH conversation than in NT, but there was not a significant difference between HP conversation and NT in reaction time. In addition, NT showed relaxed braking deceleration compared with both HF and HH conversations at red traffic lights. The present study suggests that talking on the phone while driving has negative impacts on performances of fatigued drivers.
