An Intelligent Multi-agent System for Urban Traffic Signal Control Leveraging Reinforcement Learning and Graph Neural Networks
摘要
Urban traffic congestion remains a critical challenge, largely due to static signal control systems that fail to adapt to real-time traffic dynamics. We propose a multi-agent traffic signal control framework that integrates Graph Neural Networks (GNNs) with the Soft Actor-Critic (SAC) algorithm under a Centralized Training with Decentralized Execution (CTDE) paradigm. Each intersection is modeled as an agent that learns to optimize signal phases based on local observations enriched with neighborhood context through a graph attention encoder. The reward function balances local intersection efficiency with global throughput and prioritizes public transport. We evaluate our approach in the Bologna-Pasubio scenario using the SUMO simulator. Our method shows its potential for adaptive and coordinated traffic control since it reduces average travel time by 87.3%, waiting time by 98.2%, and the number of halting vehicles by 84.3% compared to a fixed-time baseline.