Number of automobile accidents by prefecture from the National Police Agency's Police White Paper. In order to average the variation depending on year, the average numbers of automobile accidents in each prefecture for the 5 year period from 2004 to 2008 have been compared.

The average number of automobile accidents per year for the 5 year period was 874,297 cases, with 688 automobile accidents occurring per 100 thousand population. Kagawa had the greatest number of automobile accidents with 1,250.72 cases per 100 thousand population. This is 1.8 times the national average. This calculates to 1 automobile accident occurring per 80 population. Kagawa also has the greatest number of automobile accident fatalities per 100 thousand population, and thus is ranked 1st for both the number of automobile accidents and fatalities.

Saga, ranked 3rd, is also ranked 2nd in the number of Automobile Accident Fatalities, and can be said to be a prefecture with many automobile accidents. Other prefectures ranked high are Gunma (2nd), Shizuoka (4th), Okayama (5th) and Fukuoka (6th), indicating no particular regionality.

There are no rankings with correlative factors of 0.4 or more or 0.4 or less, considered highly correlated, and there seems to be no association with other rankings.

Although there was a clear positive correlation between the number of automobile accident fatalities and the number of automobile registrations, it is interesting to note that there is no regionality in the number of automobile accidents and that it is not related to other social trends. This may be a shrewd guess, but there may be differences in whether or not accidents are reported as automobile accidents depending on the police department of each prefecture. This refers to differences in the number of aribitrary accidents. Because there is a clear inclination in the number of automobile accident fatalities believed to have less room for arbitrariness, this possibility cannot be ruled out.

One other possibility may be in the rate of automobile accidents settled amicably out of court. However, because whether or not accidents are settled amicably is believed to be most probably related to prefectural natures in which case some correlation with other rankings would probably be seen, this possibility may not be that high.