Regional differences and determinants of environmental efficiency in China's road transportation industry

The spatial imbalance of road transportation hinders environmental efficiency (EE) improvement. Moreover, the driving factors and evolutionary characteristics of EE regional differences remain unclear. To clarify these, we calculate the EE of thirty Chinese provincial road transportation industries from 2008 to 2020. We also investigate regional difference decomposition and EE evolution trends while exploring the drivers of EE in three regions. The results show that the overall EE presented a fluctuating upward trend and evident spatial differences. Transvariation intensity was the primary source of the widening gaps in provincial EEs nationwide. Additionally, technological progress and increasing water and railway transport contribute to improving the eastern region's EE while decreasing the EE of the central region. Rising population scale improves the EE of the eastern and central regions, while strict environmental regulation improves the western region's EE. Road infrastructure improvements prominently increase the EEs in all three regions.