PCE in Analysis Models of the Number of Following Vehicles on a Two-Lane Road
This paper analyzes the influence of heavy-duty vehicles (HDV) on the traffic capacity of a two-lane road depending on weather conditions. The influence of the heaviest vehicles moving is expressed by the passenger car equivalents – PCE. The research was performed in Bosnia and Herzegovina, on section M-17 of the highway that tangents (touches) the zone of the city of Doboj, where the values of PCE for heavy-duty vehicles were measured at three sections with interference of on ramps and off ramps. By determining the time headway, PCE factors and their influence on traffic capacity were analyzed. The research was done for three time headway variants PC-HDV, HDV-PC and HDV-HDV. Total measured PCE factors’ value on the highway for all three sections and all three variants is 1.584; while comparing this value with HCM-2010 (Highway Capacity Manual) (TRB, 2010) it is between 1.4 and 1.5 (progressively decreasing with flow) which presents substantial deviation. That is why mathematical models for determining PCE of heavy-duty vehicles of two-lane road were developed in function of number of the following vehicles on dry and wet roadway. Developed model for establishing the PCE is based on determining time headway, which could be used to determine PCE values for particular number of following vehicles without interruption.