Research on Road Vehicle Carbon Emission Estimation Based on CiteSpace and VOSviewer: Knowledge Graph Construction and Hotspot Evolution

To systematically reveal the research dynamics and frontier trends in the field of road vehicle carbon emission estimation, this paper conducts a multi-dimensional analysis of 1,446 articles from the Web of Science (WOS) core journals spanning 2005 to 2025, based on bibliometric methods. Using VOSviewer and CiteSpace tools, knowledge maps were constructed, and research hotspots, knowledge foundations, and developmental trajectories were analyzed through keyword co-occurrence, burst term detection, and timeline evolution methods. The study finds that: (1) The field has evolved through an initial stage (before 2011), a growth stage (2011–2015), and a mature stage (after 2016), with annual publications exceeding 100 after 2020. China (contributing 37%) and the United States (19%) are the most productive countries, while Germany leads in average citations per article (44 times); (2) Research hotspots focus on three major themes: “fuel consumption,” “electric vehicles,” and “vehicle routing problem.” Post-2015, “plug-in hybrid” and “dual-carbon policy” have driven a significant increase in burst strength; (3) Methodological evolution shows a trend from “static models → dynamic life cycle assessment → multi-source data fusion.” Knowledge maps reveal gaps in cross-disciplinary research between emerging technologies (vehicle-road collaboration, autonomous driving) and traditional estimation models. This study is the first to systematically review the field's dynamics from a bibliometric perspective, providing theoretical support and data references for optimizing carbon emission estimation models and formulating low-carbon transportation policies.