More than half of traffic accidents on arterial road networks occur at intersections. To enhance traffic safety, it is essential to identify the risk factors with qualitative manner, and to reform the configuration of intersections and improve the traffic management for removing the risk factors. In this study, first we collected the data of intersection geometric attributes and lane configurations by using virtual database (cf. Google Earth and Google Street View), which was integrated with the data of traffic accidents, road networks, and traffic volume. Then, Poisson regression models were applied to statistically identify the risk factors on categorized traffic accidents. Finally, the expected number of reduction of traffic accidents are estimated based on the regression models when the reformations are applied to the intersections in Kagawa. As a result, those findings are obtained; (i) the geometric attributes of intersections are significantly varied among prefectures (Kagawa, Shiga, and Aichi), which can be considered as regional characteristics; (ii) as the size of intersections becomes large, the risk of traffic accidents becomes worse, which implies that downsizing of intersection may contribute to improve the traffic safety; (iii) according to the proposed reforming scenario for intersections in Kagawa, there is a potential that the total number of traffic accidents could be reduced by more than 35%.
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