Recently in Japan, the occurrence of traffic accidents by elderly drivers has become a social problem. It has been reported that traffic accidents caused by elderly drivers are caused by decline of cognitive impairment and physical function due to aging.
Aging also affects the driving behavior of the driver. Therefore, it is important to evaluate the long-term change of driving behavior. If the long-term change of the driving behavior can be evaluated, it can be used as a judgment for returning the driver's license by elderly drivers. However, there is no previous study that quantitatively evaluates the long-term change of driving behavior by elderly drivers.
Therefore, in this study, we analyze the long-term change of driving behavior by elderly drivers. This analysis uses data collected by car insurance companies. This data records driving information (vehicle-speed, 3-axis acceleration, vehicle position, driving date) and cognitive ability by an elderly driver from the present to 3 years ago. The evaluation indicator of driving behavior used the occurrence ratio of sudden braking. The occurrence ratio of sudden braking was calculated for each elderly driver from the present to 3 years ago.
In conclusion, it was cleared that the occurrence ratio of sudden braking by elderly drivers increases with aging. In particular, this secular change is remarkable for elderly driver who has low cognitive ability. Furthermore, it was shown that there is possibility to prevent elderly drivers from causing traffic accidents by monitoring their occurrence ratio of sudden braking.

Elderly Driver，Driving Ability, Cognitive impairment