Determining Accident - Prone Locations on zanjan - Abhar Freeway in Various Weather Conditions Using Geographic Information System

Road accidents are one of the main causes of mortality and serious injuries. Several factors may play a role on the occurrence of accidents. One of the important factors which in flounce on the traffic safety is unsuitable condition of climate. Among the factors that have role on a road accident، the share of climate phenomena، such as frost، rain، clear (sunny) weather is more than others. In this article effect of climate on road accident in Highway of Zanjan- Abhar (a part of freeway or Tehran- Tabriz) that is one of the most important roads in Iran، and connects the Capital city and northwest of Iran. For this purpose the daily traffic data for the years1388-1387، as well as weather conditions (clouds، sun، rain and snow) in the form of COM113 and 114 have been studied and on the frequency of accidents in each and every piece of climate zoning map the risk of accidents have been drawn using ArcGIS. Length of freeway of Zanjan- abhar is 104 Km. Results of classification and important factors show that %82 of accidents in sunny weather، %13. 1 in cloudy weather، %2. 8 in snowy weather and %1. 98 in rainy condition occurred. Also between 60-80 km and between 0-20 km have most amount of danger of accidents in most of climatic condition. Most of accidents occurred between 17-19 o''clock (simultaneous with sunset and oblique angle of radiation) and most of accident in these times was damaging، mayhem and deadly in type.