Investigation of the effects of vehicle composition on urban traffic flow

Rapidly increasing vehicle traffic in developing cities influence negatively daily life. For this reason, management of traffic flow and traffic facilities is an important aspect for their usage in a highly effective way. Along with the increase in the number of vehicles, the amount of heavy vehicles in the traffic also increases rapidly and accordingly there is a serious drop in capacity, delay and increase in environmental pollution. The heavy vehicle effect in the study, delay, headway and queue length values were determined by taking the performance criteria in traffic facilities. Simulation program, traffic analysis program and analytical methods were used for analysis. Passenger Car Equivalent (PCE) has been calculated to evaluate the heavy vehicle effects. The surveyed highway sections are signalized intersections and multilane urban highways. Within the scope of the research, various capacity and level of service determination methods used in the analysis of traffic flows used to be examined. The effect of the heavy vehicles in the traffic flow on the traffic flow at intersections and arteries was determined by examining the delay and capacity parameters. In this study, it was collected data with the video camera and the traffic facilities under examination using simulation programs. Calibration and validation procedures were performed to reflect the current intersection conditions. The results were evaluated and the heavy vehicle effect was determined.