b. sari sarraf

Road accidents are important factor of deaths and serious injuries both in living and financial aspects. It threatens severely human societies. Among the climatic factors playing role in road accident such as precipitation, snowing, blizzards, ice, fog and etc. In this study, their effects in Tabriz-Jolfa road were studied and analyzed. This road with 130 km length is one of the most important connecting roads of East Azerbaijan. Therefore, data and information related to road accidents which occurred during the years 1388-89 along with the data on climatic conditions in each hour were analyzed by using the statistical methods of regression, and then by Arc-GIS software, and using the Kriging interpolation method. The accident risk map in each of the climatic conditions was prepared and drawn. Results show that road section between 25-30, and 60-70, and 125-130 km in sunny and clear sky conditions, the road section between 1-5, 25-30, 65-70, and 120-130 km in cloudy conditions, section between 22-35 km in rainy conditions, and 42-55 and 105110 km in snowy conditions, 55-65 and 105-110 km in foggy conditions, 22-30 and 105-110 km during hazing hours bear higher risks of accidents.

In recent years the role of climate conditions as one of the most important factors affecting road accidents has attracted the attention of many researchers; and many studies have been done in this field. This research investigates the effects of climatic parameters on road accidents in one of mountainous roads of Iran (Sardasht-Urmia Road). For this purpose, data of accidents and hourly data of climate collected form 2005 to 2007 period of time and them investigated using regression analysis, and interpolation methods. The climatic parameters of frost, snow, precipitation, cloudiness, fog and sunshine selected as the independent variable, and the occurred accidents in the research spatial area were selected as the dependent variable. Results showed that the sunshine condition as a climatic parameter has had the highest effect on road accidents in the research area and the snow and frost condition acquired the second and third rank respectively. The accidents zoning maps of Sardasht-Urmia road has been drawn in multiple climatic conditions. At the end of research some suggestions offered in order to increasing security and decreasing accidents in mentioned road.

Based on existing data’s , thousands of people die on road accidents each year that its great cultural, economical, and social effects threatens human societies severely. According to new information in 1387 Iran’s part is about 28000 sacrificed Person which is a national disaster (seif nia-1387) In this research road accidents on AharTabriz road in rainy and fogy air conditions a 6 year statistical period has been conveyed for the purpose of conveying the role of this phenomena on occurring road accidents the data’s reported by AharTabriz climatology station has been used and air condition at the moment of occurred accident which has been reported by the information center of the police has been adjusted. In this research the density map and number of road accident in rainy and fogy climatic condition has been planned by using GIS and the relationship between the accident and rainy and fogy days has been studied as a single line by using Pierson and Regression correlation. Statistic based convey (search) show that between the number of accidents and each rainy and fogy climatic conditions is a positive and strong relationship .Also it became realized KM 5-12-45-69 under rainy and KM 12-90 in fogy days are more dangerous condition in causing accident on studied road