Space Occupancy Method for Estimation of PCUs of Vehicles at Different Speed and Flow Ranges on Urban Road

Abstract

The problem of quantification of volume under heterogeneous traffic has been addressed by converting the different types of vehicles into equivalent passenger cars and expressing the volume or capacity of roads in terms of PCU per hour. The traffic movement under heterogeneous traffic condition differs, however, significantly from that of homogeneous traffic in respect of the pattern of occupancy of road space by vehicles. Video graphic technique was used for the traffic flow data collection. A Traffic Enumeration Software was used for extracting speed, flow and headway data. Space occupancy method was used for PCU determination where in the space headway of each vehicle was also taken into consideration along with the projected area of the vehicle. Dynamic PCU values of different vehicles were found out corresponding to both speed and flow ranges. Reliability of dynamic PCU values of different vehicles is also determined by using density.