Traffic has increased rapidly in recent years, causing road congestion. Traffic volume information is crucial for designing, analyzing, and planning roadway network systems. Therefore, there must be a metric for assessing traffic flow rate or volume, where all different types of vehicles in mixed traffic volume are collected or brought to only one unit, namely PCU. As a result, the passenger car unit is an essential tool in transportation and highway engineering. There is a lack
of studies of passenger car equivalents according to traffic conditions and various factors in Egypt. The main objective of this paper is to determine passenger car unit (PCU) values for varied vehicle types under heterogeneous traffic conditions on Egyptian highways and intercity roads. By analyzing the impact of traffic volume, speed, vehicle dimensions, and road characteristics, the research seeks to enhance traffic modeling and planning efforts. The speed-area/Chandra method
will be employed to estimate PCU values. Required data were gathered from three main highways: Cairo-Alexandria Agriculture Road, Shubra-Banha Al-Hur axis, and Western Desert Road. The results show that the PCU values for various vehicle types across a wide range of traffic volume and highway conditions vary significantly due to vehicle types, traffic volume levels, and roadway characteristics.