Urban traffic light control is an important and challenging real-world problem. By regarding intersections as agents, most of the Reinforcement Learning (RL) based methods generate actions of agents independently. They can cause action conflict and result in overflow or road resource waste in adjacent intersections. Recently, some collaborative methods have alleviated the above problems by extending the observable surroundings of agents, which can be considered as inactive cross-agent

more »

... ion methods. However, when agents act synchronously in these works, the perceived action value is biased and the information exchanged is insufficient. In this work, we propose a novel Multi-agent Communication and Action Rectification (MaCAR) framework. It enables active communication between agents by considering the impact of synchronous actions of agents. MaCAR consists of two parts: (1) an active Communication Agent Network (CAN) involving a Message Propagation Graph Neural Network (MPGNN); (2) a Traffic Forecasting Network (TFN) which learns to predict the traffic after agents' synchronous actions and the corresponding action values. By using predicted information, we mitigate the action value bias during training to help rectify agents' future actions. In experiments, we show that our proposal can outperforms state-of-the-art methods on both synthetic and real-world datasets.