Transport Problems (Jan 2010)
Influence of roadway width and volume to capacity ratio on PCU values
Abstract
The objectives of this paper are to determine the influence of volume to capacity ratio on Passenger Car Unit (PCU) values, speeds of the vehicles and volume of vehicles in PCUs. The limitation of Highway Capacity Manual’s PCU values is ex-plained. Statistical analysis determined that there is a significant difference in volume of cars only between homogeneous and heterogeneous traffic conditions for various road widths. Hence the PCU values of heterogeneous traffic are recommended for the design of traffic systems over homogeneous traffic conditions. The results of the present study shows that for heavy vehicles, SUVs and motorcycles, the PCU values as a function of volume to capacity ratio vary from 0.8 to 2.8, 1.0 to 2.3 and 0.2 to 0.65 respectively. The v/c ratio has a large influence on PCU values as found in this study. Under similar traffic conditions of this study, that exist elsewhere in the country, the values obtained in this study are recommended for use in the analysis and design of traffic engineering facilities.
