Based on Spatial–Regional Heterogeneity Perspective: Environmental Regulation Impacts on Green Transformation of Transportation

In the context of the urgent green transformation of China’s transportation sector, environmental regulation (ER) provides an essential opportunity to promote the green development of the transportation sector. This paper proposes a research framework to elucidate the spatial impacts of ER on transportation’s green transformation. First, the green total factor productivity (GTFP) level of China in 2018–2022 is assessed using the super efficiency SBM-GML model that considers non-desired outputs, and the spatial heterogeneity characteristics of transportation’s green transformation are analyzed. Then, the level of ER is quantified, and the spatial Durbin model is applied to reveal the spatial–regional heterogeneous linkage effect of ER on the green transformation of transportation. The results of the study are as follows: (1) The green level of China’s transportation has been increasing, but regional disparities are still obvious. Specifically, the spatial pattern of greening level is the Eastern region > Northeastern region > Central region > Western region. (2) The transportation’s green level of Chinese provinces, in general, shows strong spatial correlation, exhibiting increasingly obvious ‘high-high’ and ‘low-low’ clustering patterns. (3) Environmental regulation has a positive spatial spillover effect and a non-linear impact on the green development of transportation, showing an inverted ‘U’-shaped relationship. Further analysis reveals that there is obvious heterogeneity in the impact of ER on the green transformation of transportation in the eastern, central, and western regions. The results of the study provide reference values and suggestions for the formulation of more targeted regional transport development policies and dynamic environmental impact policies.