Amir Masoud Rahimi - Faculty of Engineering, Department of Civil Engineering, University of Zanjan, Zanjan, Iran.
AmirMohammad Parvini - Department of Civil Engineering, Faculty of Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran.

currently, most parts of the world have shifted from traditional traffic circles to modern roundabouts with respect to the role of roundabouts in reducing accidents, increasing safety, lowering the maintenance costs compared to traffic circles with their improper functional and safety experiences. In this study, field data collected from a current traditional roundabout was analyzed by the software AIMSUN and the obtained numbers were recorded. The modern roundabout was designed by changes in the traditional one, considering the geometric standards listed in regulations. Then, the modern roundabout was analyzed by applying a heterogeneous traffic by a micro-simulation software SIDRA (5.1). The function, capacity and safety of the roundabout was analyzed assuming the superiority of modern roundabouts and acceptable LOS. The obtained results indicate that the function, capacity and safety of modern roundabouts are better than traditional ones.

Traditional Traffic Circles, Modern Roundabout, AIMSUN, SIDRA