The Study of Effect of Road Width on Passenger Car Units (PCU) of Vehicles under Heterogeneous Traffic Conditions

Abstract

Passenger car units (PCU) are used to represent the effects of varying mixed vehicle types on traffic stream. In this paper the required data is collected at eight sections of main highways of Nepal using a digital video recorder which eventually analyzed the traffic characteristics and PCU values was calculated. The study found traffic composition of Bus, Truck, LCV and Car are increasing with the increase in carriageway width but the composition of volume is found to be highest in smaller carriageway width. The speeds of all categorized vehicles are increasing linearly with the increase in carriageway width. It is found that PCU values obtained for motor cycle from all sections are smaller than the values given in NRS and for Bus, Truck, LCV found higher than the value given in NRS 2070 .This study has shown the impact of lane width on the PCU for different categories of vehicles on a Highways. It is found that the PCU for a vehicle type increases with increasing carriageway width.