As roadway alignment has a significant impact on the drivers on roads, careful consideration must be given to road alignment in order to reduce road accidents. Sharp curves and steep grades, for example, are known to increase the potential for accidents, and should be avoided wherever possible. In addition, the frequency of traffic accidents may vary even on roads with the same alignment if their facilities or the configuration of their cross sections, etc., differ. Thus, in designing the road alignment to minimize road accidents, it is necessary to also consider the placement of facilities and the configuration of the roadway cross section. This report seeks to provide valuable information for use in the road alignment design process by analyzing correlation between road alignment, traffic conditions and road accidents. One example of the findings of this study involved a comparison of the lane deviation accident rate on curves on four-lane roads and two-lane roads. The comparison revealed a higher accident rate on two-lane roads, and also found that the smaller the radius of curvature, the higher the accident rate, particularly on two-lane roads. In this way, a great deal of new knowledge has been obtained.
Samenvatting