The Analysis the Role of Motorcycles on Saturation Flow Rates at Signalized Intersections in Gorgan

One of the traffic parameters associated with the traffic conditions for each country is saturation flow rate at signalized intersections. One of the vehicles that is impaired the capacity of Signalized Intersections are motorcycles, that affect the saturation flow rate. Checking this field shows that the motorcycles due to their small size compared to other vehicles can cross the intersections in particular forms. In this study, motorcycles at an intersection are divided into two groups, in the traffic flow and out of it that both of them affected the saturation flow rate. Inside flow motorcycles are defined as those that are located next to or behind other vehicles and when the light becomes green, pass through the intersection with other vehicles. Motorcycles outside the flow are called to those that located in front of the stop line and they are the first vehicles that exit the intersection after the light become green. The methodology of this work is to use a video camera mounted on a tripod on the sidewalk that focuses camera lens on pedestrian lane. Recording started when the light turn to green and stopped when it became red. The purpose of this paper is to collect traffic data of the intersection by screen capture, calculation of observed saturation flow rate based on the motorcycles in the flow, estimate the saturation flow rate by Malaysian HCM based on the motorcycles out of the flow and at the end, comparison of observed and estimated saturation flow rate. The results of this study indicate that in the estimation of saturation flow rate, only the motorcycles in the flow should be considered.