Capacity Analysis and Signal Timing Design (A Case Study of Zero Km Intersection)

Abstract

This report comprehensively analyses the existing conditions at the Zero KM Intersection and its various access routes. The primary objective is to evaluate the intersection's capacity and design appropriate signal timings. As one of the busiest and most significant intersections in the valley, connecting key areas such as Srijana Chowk, Lakeside, and Parsyang, its performance was assessed regarding control delay using methodologies from the Highway Capacity Manual (HCM) 2000. Traffic volume was manually measured, focusing on weekday office hours from 9:00 am to 11:00 am and 3:00 pm to 5:00 pm. Results indicated motorcycles and bicycles constitute the highest traffic volume, while heavy goods vehicles have the least. The peak 15-minute flow during peak hours was used to calculate the Peak Hour Factor (PHF), informing further calculations. A standard saturation flow rate of 1900 PCU/hour/green/lane was adjusted using various factors for each lane direction. Vehicle movements were categorized into lane groups labelled 'A' to 'F,' and control delay data for each leg and flow direction was used to determine the Level of Service (LOS). Finally, manual signal timings were designed using Webster's Method, with the more excellent value of each phase utilized to calculate the total cycle length.