Impact Of Road Geometry Traffic Condition on PCU Values Using PARAMICS

Abstract

Traffic condition in India is highly heterogeneous condition, where vehicles of varying static and dynamic characteristics occupy the same space. Expressing traffic capacity in terms of number of vehicles passing a given section of road or traffic lane per unit time will be inappropriate under these conditions. The problem of measuring traffic volume and traffic capacity of such heterogeneous traffic can be worked out by converting the different types of vehicles into equivalent passenger cars and expressing the capacity in terms of Passenger Car Unit (PCU) per hour. The objectives of this study are to develop capacity guidelines for the traffic flow on NH - 17 and to evaluate the effect of carriageway width and traffic composition on the PCU value of all the categories of vehicles. PARAMICS micro simulation software is used in this study. The PCU values of different categories of vehicles estimated from the study under heterogeneous traffic condition for observed roadway conditions and traffic compositions vary significantly with change in traffic volume. The study of effect of variation in road width under heterogeneous traffic condition on PCU indicates that for any category of vehicle, PCU value increases with the increase in road width. The results of the simulation experiment conducted to study the effect of traffic composition on PCU value reveals that at a given volume level, the PCU value for any category of vehicle under heterogeneous traffic condition decreases when their proportion in the traffic stream increases.