Passenger Car Equivalents for Vehicles at Signalized Intersections within the Kumasi Metropolis in Ghana

Abstract

Passenger car equivalents (PCEs) used in Ghana have been adopted from other countries and, therefore, cannot be said to capture the impact of local conditions in signalized intersection analysis. In this study, passenger car equivalents were evaluated for three vehicle categories; cars, medium vehicles, and trucks, which use signalized intersections within the Kumasi Metropolis, Ghana. The objective was to develop PCEs which truly reflect the prevailing traffic mix, flow conditions and the effect of roadside friction at the intersections. Data was collected on discharge headways at eleven signalized intersections controlled by pre-timed signals,and using the headway ratio method, PCEs of the three categories of vehicles were estimated. PCE values were higher at intersections with roadside friction than those at intersections devoid of such friction. In comparison, the values obtained from the study are larger than those adopted from elsewhere and probably reflect more accurately the impact of local conditions on discharge at the intersections. This underscores the need to develop PCEs appropriate to local conditions rather than adopt from other standards.