In the early of '90s, number of fatal accidents caused by the young drivers who are less than 24 years owned one third of total number of fatal accidents in Japan. However, number of accidents caused by the young drivers has been decreasing rapidly since 1992. Therefore, considering the effectsof cohort on aspects of the younger generation will help in understandingthe latest decline of number of fatal accidents in Japan. This study investigated the effects of age, period and cohort on the number of fatal accidents in Japan. The Bayesian Cohort Analysis is used to analyze changes ofthree effects through the use of a wide-ranging set of statistical techniques. We used the number of driving license holders as an exposure value. Results of the study that the effects of age, period and cohort indicated by the model were reasonable and understandable. Also, the cohorts born in1967-71 and 72-76 has a large increasing effect on the average effect on the number of fatal accidents, and the latest cohort born in 1982-86 has alarge decreasing effect. Also, period has a large decreasing effect on the average effect. The model indicated that traffic safety activity in Japan coordinated between many kinds of organizations related to traffic safety had some successful results. It should be noted that the number of driving mileage per age group was more desirable as an exposure value.
Samenvatting