عنوان مقاله [English]
Safety of roads is one of the most important aspects of traffic and transportation planning in the world. The high expenditures imposed to the societies due to accidents have made the safety of roads a very significant objective in traffic engineering issues. This paper studies the interaction between the pavement index of rural two lane roadways (the destruction of pavement, the skid effect and the road width) and the daily traffic volume effect on the rate of accidents and their prediction by multiple regression models. The results of this research show that:1. In rural two- lane roadways the skid coefficient is the most important factor in occurrence of accidents, in low traffic situations, while in high traffic hours the effect of road width is more significant. This issue may be interpreted in this way that in low traffic volume, the speed of vehicles is higher and thus the skid effect is more significant, while at the same time, in high traffic situations the vehicles are influenced by the speed of the adverse side vehicles and thus the width of the roadway becomes more important.2. Generally speaking, in rural two lane roadways, the skid reduction effect in reduction of accidents is more important in reduction of accident rate as compared to that of destruction of the roads pavements3. In two lane rural roadways, the road width is the most important variable after AADT (Average Daily Traffic) and the skid and then destruction of pavements are amongst the most important factors in accidents rate, accordingly.