Performance evaluation of the HCM 2010 platoon dispersion model under midblock pedestrian and truck traffic friction conditions

The urban street segment analysis chapter of the Highway Capacity Manual 2010 provides a methodology for evaluating automobile performance on street segments within an urban roadway network (TRB, 2010). The methodology involves applying a platoon dispersion model to predict platoon arrival profiles at a downstream signalized intersection; using the predicted arrival flow profiles to compute the proportion of vehicle arrivals on green, and subsequently compute the control delay, average travel speed and level of service (LOS) of the segment. The predictive ability of the HCM 2010 platoon dispersion model has not been independently evaluated using field data. This paper, therefore, uses field data to evaluate the performance of the HCM 2010 platoon dispersion model under friction and no friction traffic conditions. The traffic friction conditions include pedestrian and vehicular interactions on urban collector street segments and the presence of trucks within the traffic stream on principal urban arterial segments. Based on the results obtained, the HCM 2010 platoon dispersion model performs relatively well in predicting platoon arrival profiles on urban street segments with no friction traffic conditions. The results, however, show the model's performance is limited on urban street segments with pedestrian and truck friction conditions.