Evaluation of signalized Intersections in Erbil City

Abstract

Signalized intersections are key nodes of urban road networks. Delay and Queue length are the major parameters that are used to qualify and quantify the performance of Signalized intersections. In this study, it was attempted to measure the queue length in the field by using video recording camera, then comparing it with the calculated values using Highway Capacity Manual (HCM 2000) method, and determine the parameters that influence it. Queue length is studied at five signalized intersections located on two major ring roads in Erbil City. The data has been collected using video recording technique. This study performs a comparison between field measured back of queue and HCM 2000 method for calculating back of queue. The results showed that the two models are close to each other in under-saturated conditions but HCM values gave higher values than measured values in over-saturated conditions obtained. Adjusted coefficient of correlation of the regression analysis was equal to 0.852, which showed a good relationship between field measured and the HCM back of queue formula in case of linear relationship. For better performance, it is recommended to redesign traffic signal timing and redesigning the intersections geometrically.