Motor Vehicle Accident in the Snowy Area

Abstract

Advances in the treatment and prevention of diseases have resulted in marked improvement in death rates among populations. A corresponding improvement in the death rate from accidents, however, has not been attained. On the basis of the mortality data available, motor vehicle accidents certainly appear to qualify as a public health problem which is to amenable to the epidemiologic approach used in other mass diseases. Whereas many factors in the environment may influence the efficiency and safety of the operators of vehicle, scanty data are available as for the frequency of motor vehicle accidents in a snowy area.
In the winter season of 1965, seasonal curves of number of road accidents, of persons injured and of persons killed all represented the lowest level throughout the year in Niigata Prefecture that has been known as one of heavy snowfall areas in Japan. It has been pointed out that snow tends to be accompanied by a lower volume of travel, but with increased accidents rates per unit of travel. Then, relation between the number of road accidents and the mean temperature outside the vehicle was worked out during January, February and March of 1965. The frequency of vehicle accidents rose sharply when the mean temperature fell below 1.5°C. The correlationship between the mean temperature and the daily incidence of slippy accidents pulled out of all vehicle accidents was found to be intimate, a coefficient being -0.42 with the probability level of less than 0.01. Slippy accidents tended to occure frequently on days when the mean temperature was below 4.5°C and its incidence was obviously high when the mean temperature outside the vehicle was below 1°C.
The findings indicate that an icy surface causes a high incidence of slippy vehicle accidents under the condition of low environmental temperature in a snowy area.