Road safety, due to a large number of accidents and casualties, has become one of the most important issues of modern society. To achieve and maintain a continuous descending trend of traffic accidents, it is necessary to study the safety problem from the point of interaction of driver, vehicle and the environment (roadway). Previous studies have shown that the most important information perceived by the driver is provided by the road itself. According to these studies, the utmost effect on the driver, when making a decision about how to drive, is made by the elements of road horizontal alignment.