Mapping the intellectual structure of the refrigerated vehicle routing problem: research perspectives and structural...

The Refrigerated Vehicle Routing Problem (RVRP) has evolved from a specialized extension of the classical Vehicle Routing Problem into a multidisciplinary research domain integrating cold chain logistics, sustainability, inventory coordination, and dynamic intelligent systems. Despite its rapid growth, the field's intellectual structure remains fragmented across methodological traditions, limiting cross-perspective integration.

This study maps the evolution of the RVRP through a co-citation network analysis of 469 articles indexed in the Web of Science Core Collection. Bibliographic data were processed using the R-TOS (Tree of Science for R) package and analyzed in Gephi, generating a network comprising 3,116 nodes and 11,341 directed edges. Modularity-based community detection, PageRank centrality analysis, and keyword frequency examination were employed to identify dominant research streams and structural patterns.

The results reveal a cohesive yet moderately modular intellectual architecture, from which four dominant research perspectives emerge: (1) algorithmic optimization and mathematical modeling, (2) perishable logistics and cold chain operational management, (3) inventory-routing integration and strategic coordination, and (4) dynamic, intelligent, and multi-objective routing systems. Cross-perspective synthesis highlights increasing methodological sophistication but persistent fragmentation, particularly in the limited integration of thermodynamic variability, deterioration dynamics, and energy consumption modeling.

A critical structural gap identified across perspectives is the widespread assumption of constant temperature along routing arcs, which constrains the physical realism of many optimization models. The findings suggest that future RVRP research should move toward systemic integration, coupling routing decisions with dynamic thermal modeling, environmental variability, and energy-thermodynamic interactions. By providing a reproducible scientometric framework and a structured synthesis of emerging knowledge gaps, this study contributes to the theoretical consolidation and future development of refrigerated routing research.