Development of a method for optimizing the traffic light cycle at intersections in mountainous areas (case study of cities in the North Caucasus)

Introduction. Optimizing traffic signal control is a critical task for improving the efficiency of transportation systems in mountainous areas, where intersections operate under challenging terrain, steep gradients, and specific seasonal traffic flow dynamics. The objective of this research is to develop a method for optimizing traffic signal cycles for two-lane intersections in mountainous areas, using the key intersection of Kosta Avenue and Moskovskaya Street in Vladikavkaz as an example. The study aims to determine rational parameters for the duration of traffic signal phases and develop an adaptive control scheme that takes into account daily and seasonal fluctuations in traffic flows in mountainous areas. Research methods and materials. The method is based on the Lighthill-Whitham analytical condition, which guarantees the absence of vehicle accumulation, and the proprietary Kudayev-Buzdov methodology, based on an analysis of traffic load factors and the stability of phase schemes adjusted for mountainous conditions. A modified Webster formula was used for the calculations. The study was conducted using remote sensing data and in-kind traffic measurements for three scenarios: morning, afternoon, and evening peaks, taking into account altitude and seasonal traffic fluctuations. Research results. Calculations showed that the intersection in the mountainous area operates reliably with a two-phase design with adjustable timing parameters. For the morning and evening peaks, the optimal cycle time was 44 seconds, and for the afternoon period, 27 seconds. A criterion was developed for switching to a three-phase mode when the proportion of left-turn maneuvers exceeds 25% and heavy vehicles are present. This allows for an increase in throughput by 10–12% and a reduction in delays by 15–20% in challenging road conditions. Discussion of research results. The results demonstrate the effectiveness of the proposed method for adaptive control in mountainous conditions. The influence of traffic flow structure, intersection geometry, and altitude factors on the selection of the optimal traffic light mode is discussed. Conclusion. The developed method represents a scientifically validated tool for optimizing traffic signal control in the specific conditions of mountainous areas. Suggestions for future research. A promising direction is the integration of the proposed method into a citywide intelligent transportation system using real sensor data and implementing machine learning algorithms for fully adaptive control in real time

Altitude (triangle · Data collection · Intersection (aeronautics · Mode (computer interface · Signal timing · Stability (learning theory · Synchro · Traffic flow (computer networking · Traffic and Road Safety · Traffic control and management · Transportation Systems and Logistics