Developing the Rate of the Traffic Accidents Model at the Undivided Roads Based On the Relationship among the Speed, Density and Traffic Flow (Case Study: Rasht- Roudsar Corridor)

Traffic accidents analysis, from the technical and safety points of view, includes its rate and severity. This research focuses on the effectiveness of the traffic parameters like, speed, volume and density on the occurrence of the accidents. Rasht- Roudsar corridor is considered as a black corridor to model the relationship between accidents rate and traffic parameters and the model validity is assured by considering another similar corridor name: Ghaen- Birjand. Using worldwide relationships of traffic parameters to localize traffic accidents rates is the main feature of this study. Using the nonlinear and multi variable regression method to develop the model shows that an exponential function would best fit. Speed- Volume diagram follows an S curve and the result explicit an inverse relationship between accident rate and car speeds with a coefficient equal to 0.25, while there is a direct relation between accidents rate and the traffic volumes with a coefficient of 0.0005.