In studying heterogeneous traffic, passenger car equivalents (PCE) play a significant role in converting the mixed traffic flow into equivalent hypothetical homogeneous traffic that consists of passenger cars only. As can be seen in the literature there are different measures of impedance (speed, density, vehicle-hours etc.) based on which PCE values are calculated for different types of vehicles. Since vehicle-hours and speed are functions of vehicle density, PCE values invariably depend on density. Measuring or estimating the density value is difficult under heterogeneous traffic conditions, and at the same time density is independent of vehicle length and vehicle width. Due to these reasons using the density value as a measure of impedance in calculating PCE values under mixed traffic conditions may lead to erroneous results. In this paper an alternative measure of density termed as area occupancy, is used as a measure of impedance to estimate the PCE values. A simulation technique is used to estimate PCE values under different traffic regimes. These values will be helpful in analyzing traffic flow patterns and in capacity analysis. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Abstract