The traffic accidents threats humans live and its increases during the time. For this reason, this paper tries to analysis the traffic accidents by assessment of accident situations. Also, study the effect of road design elements and regulations coincide with case study in two methods applied first the five parameters individually tested. Then effective parameters tested together, correlation between accidents and the parameter, the roads and streets must design carefully and according to specifications and criteria. In this paper trying to indicate the weak points of road network and fixing this points to avoid them in the future. The ring road have a negative aspect because it extends the path and collecting local roads more than the straight paths. Also, restriction of sight distance occurs, the topographic of Erbil city is helpful in avoiding vertical curves, but the horizontal curves presented with concentric ring roads.