Optimizing traffic flow at signalized intersections is essential for improving urban mobility in mixed traffic environments. This research paper explores dynamic Passenger Car Units (PCUs) at signalized intersections in Indian cities, addressing a range of vehicle types. A specialized methodology was developed to accurately calculate PCUs and saturation flow rates under various traffic conditions. The study evaluates the impacts of traffic composition, lane width, and approach grade on saturation flow rates. Key findings indicate that lane width and turn radius significantly affect the capacity of left-turn lanes, highlighting their critical role in enhancing intersection efficiency. Additionally, as traffic volume increases, PCU values decrease more for heavy vehicles compared to smaller ones, and peak-time saturation calculations reveal higher degrees of saturation at lane approaches.