Urban congestion remains a persistent challenge in rapidly growing cities of developing countries, particularly in regions burdened by prolonged conflict and infrastructural neglect. This study investigates an adaptive, low-cost traffic signal control approach tailored for Sana’a, Yemen a city facing chronic traffic congestion, limited data infrastructure, and constrained public resources. Using the open-source traffic simulator SUMO (Simulation of Urban Mobility), we modeled a key intersection in Sana’a to evaluate the performance of two controllers: a traditional fixed-time signal and a context-aware adaptive controller that dynamically adjusts signal phases based on real-time vehicle density.
The simulation integrates machine learning for congestion classification and real-time signal adaptation, producing performance metrics across vehicle throughput, queue length, and signal efficiency. Results reveal that the adaptive system significantly reduces congestion compared to the fixed-time controller, demonstrating better responsiveness to fluctuating traffic loads. Importantly, this solution requires no expensive hardware or centralized infrastructure—making it ideal for conflict-affected, low-resource urban settings.
The findings underscore the potential of simulation-driven planning and low-cost AI methods in supporting smarter urban mobility, even in fragile cities. This work offers a scalable blueprint for traffic management in similar contexts across the Global South.
Introduction
Urban congestion is worsening in resource-constrained and conflict-affected cities like Sana’a, Yemen, where outdated traffic systems, poor infrastructure, and limited surveillance make traditional solutions infeasible. Intersections such as Al-Zubairi Street and Al-Hasaba face severe traffic delays, fuel waste, and pollution due to unregulated and rigid traffic signals.
2. Proposed Solution
This research introduces a low-cost, adaptive smart traffic light control system customized for Sana’a. Using the SUMO (Simulation of Urban Mobility) platform and machine learning, it simulates real-time signal control based on vehicle density and congestion prediction.
Key Features:
Uses Random Forest classifiers for adaptive signal control.
Operates on basic inputs (e.g., low-cost traffic cameras or loop detectors).
Avoids expensive centralized infrastructure.
Provides interpretable and robust performance in low-data, high-noise environments.
3. Literature Review Insights
Fixed-time signals are ineffective for dynamic traffic flows and worsen congestion in cities like Sana’a.
Adaptive Traffic Signal Control (ATSC), enhanced by AI and simulation tools (like SUMO), significantly improves traffic throughput in high-tech cities—but less is known about low-resource applications.
Random Forest models are preferred in sparse-data conditions due to their simplicity and resilience.
Prior low-cost deployments in cities like Lagos and tier-2 Indian cities show feasibility on edge devices like Raspberry Pi.
In conflict zones, systems must account for irregularities like sudden road closures, erratic driving, and degraded infrastructure.
4. Methodology
Study Area: A high-traffic intersection in Sana’a with no automated sensing.
SUMO Modeling:
Created using OpenStreetMap data and manual configurations.
Two traffic light programs were simulated: Fixed-time and Adaptive.
Simulation Setup:
10-minute sessions with 10-second data intervals.
Metrics: vehicle count, signal durations, predicted congestion.
Data stored in CSV logs and used for visual traffic analysis.
5. System Architecture
The system architecture simulates traffic flows, classifies congestion levels using trained ML models, and adjusts signal timings accordingly—all within the SUMO platform. The model loops continuously to adapt signal control in near-real time.
Conclusion
This study presents an adaptive and cost-effective approach to traffic signal management for Sana’a, a city facing chronic congestion in a low-resource, conflict-affected environment. By leveraging SUMO simulations, a Random Forest-based congestion prediction model, and fixed versus adaptive signal timing comparisons, the research has demonstrated the feasibility and advantages of intelligent traffic control in such constrained settings.
The fixed-time traffic controller, commonly used in many developing countries, was compared with an adaptive controller integrated with congestion prediction logic. SUMO simulations illustrated that the adaptive system achieved better performance in managing vehicle accumulation and green light duration allocation. The simulation logs and plotted comparisons confirm a clear reduction in average vehicle presence and improved responsiveness of signal phases.
Key findings include:
• The adaptive model significantly reduced vehicle queue lengths at peak intervals.
• Using local simulation data to retrain the ML model allowed for better context-specific predictions of congestion.
• Fixed-timing controllers failed to respond to real-time traffic variation, leading to inefficient signal phases and longer delays.
This work also illustrates the power of open-source tools like SUMO, joblib, pandas, and matplotlib in building full-stack traffic management systems without requiring commercial platforms or advanced infrastructure. The success of this pilot highlights how modest computational models can be deployed to enhance urban mobility even under conflict, lack of monitoring systems, and unreliable power.
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