The impact of environmental regulation and logistics industry agglomeration on road green logistics efficiency: Evidence from China

Decoupling road logistics from road freight activity is essential for controlling CO 2 emissions, and environmental regulation (ER) can serve as a key mechanism to achieve this goal. At the same time, logistics industry agglomeration (LIA), when reasonably managed, can enhance logistics efficiency. However, tensions arise because the rapid expansion of the logistics sector exerts substantial environmental pressure, even though the development of green logistics may partially offset its carbon impacts. Against this backdrop, this study investigates the interrelated effects of ER, LIA, and road green logistics efficiency (RGLE) in order to improve the operational sustainability of road logistics systems. Using panel data from 30 Chinese provinces spanning 2008–2023, we explore the effect of ER on RGLE and examine how this relationship varies with the inclusion of LIA using moderating and threshold effect models. Empirical results show that RGLE initially declines before increasing, with significant spatial variability. Interestingly, econometric findings indicate that ER does not directly improve RGLE but effectively enhances it through its interaction with LIA. Furthermore, the impact of ER on RGLE exhibits a “U-shaped” relationship under different LIA values. Consequently, this study concludes with recommendations to improve RGLE through optimizing LIA, and strengthening regional linkage.