The US Highway Capacity Manual (HCM) delay progression factor method is extended to the prediction of queue length, queue clearance time, proportion queued (stopped), queue move-up rate and stop rate. This is achieved by the introduction of an additional progression factor and adoption of the HCM overflow term adjustment factor for use in other formulae. This provides a simple method to allow for the effects of platooned arrivals on the performance of coordinated signalised intersections. The method is useful at the level of basic capacity and performance analysis of a single intersection where detailed platoon patterns generated at upstream signal stop lines are not available. The arrival types defined by the HCM as the basic input to define the characteristics of platooned arrivals are adopted for use in calculating the additional progression factor in the same way as the original HCM progression factor for delay. Application of progression factors to the cases of two green periods per cycle, shared lanes, opposed turns and short lanes is also discussed. A formula for estimating the travel time (and associated travel delay) of an uninterrupted movement is given in the Appendix.
Abstract