Review the parameters of geometric design of roads and its influence on highway safety (Iran's comparative analysis and case study)

Fast increase and widespread use of automobiles since 0961`, caused some negative results in all around the world. One of the main subsequent problems of this phenomenon is car accidents. Factors which cause car accidents can be categorized by considering their relation with humans, roads, and cars. In highway design stage, it is very important in highway safety to make coordination between human factors and two other factors. It seems that human factors such as driver, pedestrian, and passenger, have the most important role in accidents. Nevertheless, controlling road factors is very easier than controlling human factors. Moreover, through a suitable geometric design, we can compensate other factors and decrease the number of accidents subsequently. So, it is obvious that creating a suitable geometric design is very important factor in road safety. In this article, factors and features of geometric road design have been reviewed, and some explanations on how and how much these factors can affect highway safety, have been provided. The relationship between safety and geometric road design has been reviewed according to results drawn from studies performed in different countries. In this regard, some data about a study which is previously performed on a section of Iran roads has been included, as well. In this study, this section has been divided into some subdivisions. Then, the number of accidents is determined in these subdivisions. After that, geometric parameters are expressed in these subdivisions. Finally, regression analysis is performed between geometric parameters and number of accidents. At the end of article, we reach to a significant relationship between some elements of geometric design, and number of accidents, and we describe the model which is used in this research and also the outcome results.

Keywords:

highway safety , geometric design of road , car accidents , Iran roads