Remote Data Collection for the IQA Delay Estimation Method

One common way to measure the levels of service of signalized intersections is to estimate delays. The call for better methods for estimating delays is the source of much research that culminated in the Incremental Queue Accumulation (IQA) method. The IQA method consists of two procedures: IQA field and IQA model. Both procedures require intensive cycle-by-cycle data collection on approaching vehicles and traffic signal timing. In a study to evaluate the accuracy of the IQA method, the real-time remote data collection facility available at the Transportation Laboratory of Brigham Young University was used to create a digital video that simultaneously records the four approaches to a signalized intersection, together with signal changes for the four approaches. By using a video image analysis program that allowed frame-by-frame analysis, it was possible to collect both vehicle arrival/departure and signal timing data that were necessary for evaluating the two IQA delay analysis procedures.