CVLight: Decentralized Learning for Adaptive Traffic Signal Control with Connected Vehicles

TL;DR

CVLight is a decentralized reinforcement learning approach that uses connected vehicle data to optimize traffic signals across multiple intersections, demonstrating superior performance and scalability in synthetic and real-world scenarios.

Contribution

The paper introduces CVLight, a novel decentralized RL scheme utilizing connected vehicle data and a new Asym-A2C algorithm for adaptive traffic signal control.

Findings

Outperforms state-of-the-art algorithms in synthetic networks.

Significantly reduces training time with pre-training technique.

Effective in real-world case study with low CV penetration rates.

Abstract

This paper develops a decentralized reinforcement learning (RL) scheme for multi-intersection adaptive traffic signal control (TSC), called "CVLight", that leverages data collected from connected vehicles (CVs). The state and reward design facilitates coordination among agents and considers travel delays collected by CVs. A novel algorithm, Asymmetric Advantage Actor-critic (Asym-A2C), is proposed where both CV and non-CV information is used to train the critic network, while only CV information is used to execute optimal signal timing. Comprehensive experiments show the superiority of CVLight over state-of-the-art algorithms under a 2-by-2 synthetic road network with various traffic demand patterns and penetration rates. The learned policy is then visualized to further demonstrate the advantage of Asym-A2C. A pre-train technique is applied to improve the scalability of CVLight, which significantly shortens the training time and shows the advantage in performance under a 5-by-5 road network. A case study is performed on a 2-by-2 road network located in State College, Pennsylvania, USA, to further demonstrate the effectiveness of the proposed algorithm under real-world scenarios. Compared to other baseline models, the trained CVLight agent can efficiently control multiple intersections solely based on CV data and achieve the best performance, especially under low CV penetration rates.