In heterogeneous traffic comprising vehicles of wide ranging static and dynamic characteristics, due to differences in dimensional and operational characteristics, poorly performing vehicles develop resistance to the movement of high performing vehicles. The subjective variable impedance caused by a vehicle considered as the measure to quantify the equivalency value. The reference (base) vehicle considered for the purpose being passenger cars, the equivalency value is termed the passenger car unit (PCU) equivalence. Although there are several methods available for the estimation of PCU values, the use of a simulation technique is found to be appropriate. In this study, PCU values for the different types of vehicles of a highly heterogeneous traffic were estimated, using a micro-simulation technique. It was found that the PCU value of a vehicle type varies significantly with variation in traffic volume. Hence, it is appropriate to treat the PCU value of a vehicle type as a dynamic quantity instead of considering it as a fixed one. (a).
Abstract