An advanced approach for estimation of PCU values on undivided urban roads under heterogeneous traffic conditions

Abstract

ABSTRACTMajority of the existing studies on passenger car unit (PCU) estimation are limited to inter-urban and divided urban roads. The characteristics of traffic on undivided urban roads are completely different from those on divided roads. This study aims to estimate the PCU values on undivided urban roads with varying traffic conditions. Estimation of PCU requires speed information for individual vehicle categories. Hence, a universal Kriging-based speed prediction model was developed and utilized for PCU estimation. The model was constructed based on the classified traffic volume and speed data that were collected by videography method on undivided urban road segments in different cities in India. The proposed model was utilized to study the effects of traffic volume, traffic composition, and carriageway width on PCU. An alternative approach of ‘Stream Equivalency Factor’ has also been suggested in this paper. Use of this approach can simplify the process of determining the homogeneous equivalent of a mixed traffic flow.