Abstract:
Saturation flow rate is one of the most important parameter in planning and design of signalized intersection other being lost times and passenger car units (PCUs). Research on these components has been carried out in most developed countries such as USA and UK where traffic conditions are ideal (properly defined lanes, flat gradient, no heavy vehicle etc). Currently in Pakistan standard western values of PCU and saturation flows are being used and signals are being designed according to these standards. However, the traffic conditions in developing countries specially Pakistan is rendered more intricate because of the heterogeneous traffic conditions such as lack of road discipline, heterogeneous composition of vehicles, faded lane markings, poor driver behavior due to lack of awareness and education. Zigzag movement by motorcyclist through traffic stream is an alarming stage due to which accidents intensity has increased. Vehicles position in lane in disturbed because every driver wants to reach the front of the queue. Due to these fundamental differences it is not appropriate to use western values of either PCUs or saturation flow rate. Therefore there is a need to develop local values. In Pakistan no research has been carried out till date to develop these values. This study focuses on developing local saturation flow rate values for Pakistan. This study is carried out on various intersections of Rawalpindi and Islamabad.
