A Critical Review of Traffic Signal Control and A Novel Unified View of Reinforcement Learning and Model Predictive Control Approaches for Adaptive Traffic Signal Control

TL;DR

This paper reviews adaptive traffic signal control methods, introduces a unified framework based on Markov decision processes, and highlights challenges and future research directions for AI-driven traffic management.

Contribution

It presents a novel unified view of ATSC approaches using Markov decision processes, enabling better comparison and understanding of existing methods.

Findings

Unified framework facilitates cross-domain analysis

Identifies common challenges in ATSC methods

Suggests future research directions

Abstract

Recent years have witnessed substantial growth in adaptive traffic signal control (ATSC) methodologies that improve transportation network efficiency, especially in branches leveraging artificial intelligence based optimization and control algorithms such as reinforcement learning as well as conventional model predictive control. However, lack of cross-domain analysis and comparison of the effectiveness of applied methods in ATSC research limits our understanding of existing challenges and research directions. This chapter proposes a novel unified view of modern ATSCs to identify common ground as well as differences and shortcomings of existing methodologies with the ultimate goal to facilitate cross-fertilization and advance the state-of-the-art. The unified view applies the mathematical language of the Markov decision process, describes the process of controller design from both the world (problem) and solution modeling perspectives. The unified view also analyses systematic issues commonly ignored in existing studies and suggests future potential directions to resolve these issues.