The Evaluation of the Impact of Road Width on Passenger Car Units (PCU) in Heterogeneous Traffic Conditions

Abstract

This study delves into the utilization of Passenger Car Units (PCU) as a pivotal metric for gauging the influence of diverse vehicle types on traffic flow. Focusing on the context of Mogadishu, data acquisition was conducted across eight key sections of major highways. Employing digital video recorders, the gathered data facilitated a comprehensive analysis of traffic dynamics, thereby enabling the computation of PCU values. The investigation unveiled a discernible trend wherein the traffic makeup, comprising bus, truck, light commercial vehicle (LCV), and car categories exhibited a positive correlation with carriageway width expansion. Nevertheless, the volume composition peaked notably in narrower carriageway widths. Concurrently, the speed of the aforementioned vehicle categories showcased a linear progression proportional to carriageway width augmentation. Intriguingly, PCU values assigned to motorcycles consistently undershot the figures stipulated in the Mogadishu Road Standards (MRS). Conversely, PCU values for bus, truck, and LCV categories consistently surpassed the MRS 2070 benchmarks. This scrutiny distinctly elucidated the intricate interplay between lane width and PCU values across distinct vehicle types, effectively underscoring the propensity of PCU values to escalate with escalating carriageway dimensions.