Driver safety is an important and often sensitive issue for seniors. Statistics show that the elderly are more likely than other drivers to receive traffic citations for failing to yield, turning improperly, and running red lights and stop signs all indications of decreased driving ability. Currently in Japan, half of the deceased in traffic accidents are elderly people. In present study, we focused on how the pedal placement affect on braking action in emergency. First, ten healthy young and ten elderly individuals were asked to perform a simple reaction experiment by foot. Then, the same subjects were instructed to complete a braking action experiment with different pedal placement condition. The results suggested that both simple reaction time and foot movement time of elderly subjects were significantly longer than that of young subjects. Moreover, the brake pedal force of elderly subjects was lower than that of young subjects. Thus, aging influenced both of simple reaction time and braking action in emergency. In addition, even the pedal placement changed characteristics of braking action of both young and elderly subjects, the most comfortable pedal placement of elderly subjects differed from young subjects.