Performance Evaluation and Improvement of Four-Legged Intersection: A Case Study of Satdobato Intersection of Kathmandu Valley, Nepal

https://doi.org/10.46610/IJTMTN.2025.v01i02.003

Abstract

Due to the higher traffic volume and limited opportunities for infrastructure enhancement, the Satdobato intersection in the Kathmandu Valley experiences extreme congestion, especially during peak hours. This study analyzes the current operating performance of the intersection through the SIDRA Intersection 8 simulation software and suggests ways to enhance it. Traffic data were obtained through videography and manually calculated to find peak hour volumes, saturation flow, and back-of-queue lengths. The base model was calibrated and validated using real data. Two alternatives were explored: (1) constructing a flyover between the Mahalaxmisthan and Gwarko approaches, and (2) implementing lead-right signal phasing with optimal timing. With the existing setup, the intersection was at Level of Service (LOS) F, with average vehicle delay at 238.2 seconds and degree of saturation at 1.320. The flyover scenario improved the performance to LOS C with a delay of 30.6 seconds, and the signal optimization timing scenario yielded LOS E with a delay of 76.7 seconds. The alternative flyover exhibited the highest improvement at that intersection. This research recommends considering pedestrian volumes, coordination between adjacent intersections, and the application of newer versions of software for fuller analysis.