New Calculating Method for HCM 2000 Queue Length Estimation Procedures with the Application of Floating Car Data

AbstractThe maximum back of queue length (MBQL) is one of the measures of effectiveness (MOEs) for signalized-intersection level of service analysis. The Highway Capacity Manual 2000 (HCM 2000) proposes a queue length calculation model, based on the Akcelik's queue model, which was developed in the 1980's, has stood the test of time as a fundamental method of traffic signal analysis. The HCM 2000 model is comprised of two terms that the first term is determined by assuming a uniform arrival pattern and the second term is associated with randomness of flow and overflow queues. However, the application of the HCM 2000 is limited as the initial queue length needs to be known at the start of analysis period for the second-term model.Using data of floating cars and loops, the authors have developed an alternative calculating method without initial queue length information for the HCM 2000 second-term queue length model. The experiment carried out at an intersection in Shanghai, China shows that the developed method can provide more accurate estimation of the queue length than HCM 2000. The later a floating car arrives in the queue, the more accurate estimation can be obtained. The proposed method is easy to understand and can produce results more reliable and accurate in citywide intersections evaluation