Determining of the Parking Adjustment Factor and the Taxi Blockage Adjustment Factor for the Saturation Flow Rate at the Outlet Legs of Signalized Intersections (Case Study: Rasht City)

The presence of taxi stops within the area of signalized intersections at the outlet legs due to unnatural behavior of the taxis such as sudden change of lanes, parking activities and stopping the vehicle to discharge or pick up the passengers have led to reduction of saturation flow rate at the outlet legs of signalized intersections and increased delay as well as affecting the performance of an adjacent lane. So far, in term of evaluating effective adjustment factors on saturation flow rate at the inlet legs of the signalized intersections, various studies have been carried out, however these adjustment factors influenced by parameters including geometrical characteristics, number of lanes, the characteristics of traffic flow and driver´s behaviors are not similar at inlet and outlet legs; and due to the difference in mentioned parameters, there has not been any studies yet at the outlet legs. Hence, the consideration of the traffic effects of these behaviors on the saturation flow rate of the outlet leg is very important. The present paper evaluates and analyzes the parking maneuver time and taxi blockage time based on the lane width as well as determining the effective adjustment factors on the saturation flow rate using recording related data at four signalized intersections in Rasht city. The results show that the average parking maneuver time is a function of the lane width and is increased as the lane width is reduced. Also, it is suggested to use the values of 7.37 and 11.31 seconds, respectively for the average parking maneuver time and the average blockage time of taxies at the outlet legs of signalized intersections for the traffic designing in Rasht city.