Validating the Incremental Queue Accumulation Method for Left-Turn Delay Estimation

This paper examines the proposed incremental queue accumulation (IQA) method for the analysis of traffic flow at signalized intersections. The paper considers the formulation of the IQA method for protected plus permitted left turns. Validation of the model is presented by using the NGSIM high-resolution vehicle trajectory data set developed for an arterial in Atlanta, Georgia. A comparison of the existing Highway Capacity Manual (HCM 2000) method with the IQA method shows that the IQA approach produces delay estimates that are closer to field measurements. Several issues associated with the arrival and departure curves produced by the IQA method are examined.