Abstract: Emerging traffic in medium and large cities is of major concern to develop a network which would be able to satisfy the needs of traffic. Intersections are a very important part of this network and are to be designed properly to handle the traffic efficiently. Un signalized intersections have a drawback of a large number of conflict points. Introduction of roundabouts at intersection had many advantages. Roundabouts eliminate the conflict points which lead to perpendicular crashes. It reduces driver confusion associated with perpendicular junctions and also reduces the queuing caused due to signalization. It is crucial to measure the performance of existing roundabouts in terms of its ability to handle the present traffic scenario. The entry capacity is found to vary immensely with the changing geometrics of the roundabout and circulating flow. A model can be developed using empirical analysis based on five such geometric parameters circulating flow and exit flow which proved to be significant for estimating the capacity. The model can be validated with the site data for checking its practicality. Performance analysis of rounabouts were also done by estimating entry capacity and capacity of weaving sections. And also level of service of both weaving sections and entry sections were found out as per HCM (2010) and IRC (65) respectively.

Keywords: Entry flow, Model, Level of service, HCM, IRC