A systematic review of node models for macroscopic network loading of traffic flows

Node models in macroscopic network loading procedures are used to distribute competing flows arising at motorway ramps, junctions, and intersections, influencing congestion and queuing delays. Despite decades of research on macroscopic node model development, a comprehensive literature review on their characteristics, categories, emerging trends, and further research opportunities does not yet exist. This study fills this gap by conducting a systematic literature review on the node models in macroscopic network loading frameworks. We identify representative characteristics of node models and then systematically classify and interpret those characteristics across existing node model studies present in the literature. We propose six general principles for node models and explore five extension categories characterising additional features. This paper makes two contributions to the field. Firstly, it provides a comprehensive classification of node model research, grounded in the proposed principles and extension categories. This classification is substantiated by relevant references and culminates in the development of a node model classification table. Secondly, it identifies future research directions and opportunities, providing guidance and insights for researchers and practitioners engaged in the study of macroscopic node models.