The effects of a mobile telephone conversation on elderly drivers' reaction time, lane position, variation in lane position, speed level, and workload were studied in an advanced driving simulator. Twenty subjects, experienced drivers in the ages 60 to 71 years, were randomly assigned to two conditions (mobile telephone and control). It was found that the conversation over the mobile telephone had a negative effect on the elderly drivers' reaction time to a suddenly appearing event. Engagement in the mobile telephone task also led to speed reduction and increased variation in lateral position. Finally, the drivers' mental workload, measured with NASA-TLX, increased when the telephone task was added to the driving task. The results were compared to the effects on twenty young drivers' behaviour, which was studied in an identical study. The comparison showed that the elderly drivers' reaction time to an unexpected event was approximately 0.40 seconds longer than the young drivers' reaction time, when talking in the mobile telephone during driving. The elderly drivers also varied their lateral position more than the young drivers, who tended to move to the right of the road and keep a steady course when talking in the mobile telephone. In contrast, the elderly drivers kept the same mean position on the road, but increased their variation around that mean. Finally, some implications for traffic safety were discussed. (A)
Abstract