ABSTRACT
In deciding which type of control to provide at an intersection, there should be some criteria used. A typical criterion used in some situations is to minimize the delay to vehicles. While there are established methods for estimating dalays at signal control, there does not seem to be any standard or well established method by which the delay to vehicles at roundabout approach can be obtained. This thesis presents a procedure by which this delay can be obtained. The signal control is used here as a typical example of any other control, the delay produced by the two controls (Roundabout and Signal Control), at various demand flows and turning problems are obtained and can then be compared. Empirically, by modelling the roundabout as a series of T junctions, with circulating flow having priority over entering flow, it has been shown in the literatures by previous researchers that the capacity prediction equation for the roundabout entries can be represented by the linear entry/circulating flow relationship. This equation gives the saturated entry flow in terms of circulating flow and some geometric parameters, basically entry width and flare. Here, with this entry capacity as obtained above, use is made of the low definition rectangular type of demand pattern