Comparing capacities at unsignalized intersections and roundabouts.

This report presents a comparative study on some of the widely used procedures and recently developed models for capacity calculation. Newly developed models consider some of the flaws in the earlier models, such as the unequal lane flows, fixed critical gaps for all lanes, and bunching. A comparison of various capacity models for unsignalizedintersections is carried out with an independent data set. The experiment involves two types of intersections namely, major /minor priority intersections and roundabouts. For each type of intersection two types of modelling approaches were considered and examined, namely empirical and theoretical gap acceptance approaches.