Evaluation of The Speed Bumps Utilization at Junctions and U-Turns on Accidents and Vehicles’ Speed and Offering Prediction Model of The Speed Bumps Effects on The Accidents Reduction

Safety indicator and range of controlling accidents is considered as one of the important criteria of evaluating transport networks. One of the effective instruments in controlling accidents and traffic is the ability to predict accidents that given this issue, traffic can be managed and the instruments of controlling speed and traffic are used. So the prediction model of the impact of using types of speed bumps in decreasing accidents has been investigated and presented in the research. For this purpose, data related to accidents in 50 junctions and U-Turns during 5 recent years in Ghaemshahr have been studied. Through field studies, parameters such as speed of vehicles, width of speed bump, height of speed bump, distance from junction, the numbers of crossing line and distances of warning signs have been selected as variable and affective parameters on the numbers of accidents. By using scattering models, the way of changes of different parameters were evaluated based on the numbers of accidents in the different places and the final model was obtained by using regression analysis in order to be used in the prediction of accidents. The results showed that if the warning signs are not used in the junctions with speed bump, it will increase the numbers of accidents up to 18% that the increase in the junctions with speed hump is about 11%.Using speed bumps and speed humps with non-standard geometry will increase the numbers of accidents 5 to 12% that the increase in the junctions having speed bumps is more than the increase in the junctions having speed humps.