PASSENGER CAR EQUIVALENT (PCE) OF THROUGH VEHICLES AT SIGNALIZED INTERSECTIONS IN DHAKA METROPOLITAN CITY, BANGLADESH

Abstract

Road traffic systems, travel patterns, and other traffic characteristics are different for each country due to differences in geometric patterns, available commuter transport facilities, rate of development in the transport sector, and so on. Consequently, many standard relations and factors used in one region may not be suited for others. Therefore, an issue comes up to determine the different traffic engineering parameters appropriate to local urban transport system characteristics. One such endeavor is to determine the passenger car equivalent (PCE) at signalized intersections for the Dhaka Metropolitan City, Bangladesh, where traffic characteristics are completely different from any other cities of the world. PCE currently used in Bangladesh is based on values given in Geometric Design of Highways (MoC, 2001), which is the modification of the values given by Webster (1958) on the study performed in the United Kingdom in the 1950s and 1960s. Presently, the situation is far different both for traffic and road users as the characteristics have changed from that time. Hence, in this paper an empirical study was carried out to determine the PCE of different types of vehicle that reflect the actual traffic conditions of Dhaka Metropolitan City. Data was collected from 10 signalized intersections and the headway ratio method was used to estimate the PCE of different types of vehicle. The main vehicle compositions observed during the study period consist of passenger cars, auto-rickshaws, mini-buses, and buses. The PCE obtained in this study were compared to values established earlier. It was found that the estimated PCE are smaller than those being used in Bangladesh.