عنوان مقاله [English]
With the rapid expansion of motor vehicle use in the world, road traffic – related deaths and injuries are rising sharply. More than one million people died at road traffic crashes in the year 2000 all around the world and according to the World Health Organization (WHO) that number could nearly double by 2020. Also the rate of serious injuries is estimated to be 20 times that of road deaths.In Iran, more than 28,000 people died in road accidents during year 2005. This is a very large number in comparison with the world road traffic deaths rate regarding its overall road length.Iranian traffic police department statistics shows about 70 percent of road crashes occur in the last 30 km of roads length near cities named "City Entrance Zone". There are some reasons available for this fact:Mixed Traffic: Because of locating different factories, workshops, farms, etc. near cities, different vehicle types comprising passenger cars, three wheels and heavy vehicles are available in "City Entrance Zone".More Access Roads: Many rural or industrial zones are located near big cities; therefore many access roads will be available in "City Entrance Zone".Different Behavior: The trips in City Entrance Zones have different situations; some of them are generated from the city, some of them will end in that city and the others will pass the city through another city, so drivers will have different behaviors in these zones.In this paper, some road parameters are discussed to find their influences on road accident rates. Moreover, road safety index (RSI) is defined versus road accident rate.With the analysis of accident data which obtained from traffic police department and gathering data from 14 road sections, and by using SPSS software, a model generated which shows the relationship between road accident numbers and road parameters (such as road traffic volume, road width, number of access roads and junctions, road vertical slope and city population). This model predicts road accident probability in any other road section and can be used in efficiency estimation of road safety solutions.