New Trial Analysis of Characteristics of Accidents and Traffic Violations by Elderly Drivers in Japan

The number of elderly drivers is increasing in Japan and ensuring the safety of elderly drivers is becoming an important issue. The authors previously conducted an analysis of the characteristics of accidents and traffic violations by elderly drivers based on the number of accidents in which they were rear-ended. This method was used in order to exclude the influence of driving frequency. As a result of that analysis, it was found that the likelihood of violations committed by elderly drivers was not particularly higher than in other age groups, while the likelihood of accidents caused by them was higher. The risk of causing an accident was judged to be about two times higher in elderly drivers than in the 35-44 year age group. However, the methodology presupposed that collisions in which a driver is rear-ended are accidents that occur randomly, and that they occur with the same probability in each age group. To verify the results of that study, we attempted a new analytical method that uses the number of stop sign violations, which are considered to occur with the same probability among age groups, as an indicator of driving frequency in place of accidents in which a driver is hit from behind (rear-end collisions). In the new analysis the risk of causing an accident was judged to be 1.24 times higher in elderly drivers than in the 35-44 year age group. In general, the risk of accidents caused by elderly drivers is estimated to be lower than in the previous study.