A Model to Optimization Roundabouts with More Than 10 Entries / Exits

Nowadays the use of roundabouts due to reduce delay time, stops delay and landscaping is more common and take place of signalized intersections. But it must have strong justifications (e.g. do not locating a roundabout for oversaturated intersections). Totally some roundabouts due to geometric design and several entries and exits should be improved besides traffic analysis. In this research a method to revise abnormal roundabouts with more than ten entries - exits will be presented. Finally a case study will be surveyed. In this case which has abnormal geometric design and heavy traffic at peak hours a methodology for these king of roundabouts will be presented.