COMPARATIVE ANALYSIS OF DELAY AND SATURATION FLOW USING VARIOUS PCU ESTIMATION METHODS

A Passenger Car Unit (PCU) is a metric used in traffic engineering to quantify the influence of various vehicle types on traffic flow, expressed as a ratio relative to a standard passenger car. PCU factors are crucial for intersection design, as they allow for accurate estimation of traffic capacity and performance by standardizing the effects of different vehicles. Traditionally, static PCU values have been used for design purposes. However, advancements in vehicle technology over the past few decades necessitate a re-evaluation of these values through field studies. This research provides an empirical analysis aimed at determining dynamic PCU values for various vehicle types, enabling a comparison with the factors recommended by the Indian Highway Capacity Manual (Indo-HCM). Data collection took place at two signalized intersections, utilizing the headway ratio method and the queue clearance rate method to estimate PCUs for different vehicle categories. Field data on delay and saturation flow were collected following Indo-HCM guidelines, employing both static and dynamic PCU values. A comparative analysis of these values was conducted to highlight discrepancies and offer insights into the relevance and accuracy of dynamic PCU values in assessing traffic flow.