Seeking spatiotemporal patterns and driving mechanism of atmospheric pollutant emissions from road transportation in china

As the most basic transportation mode, road transportation is a main contributor to atmospheric pollution. Different geographical locations and socioeconomic conditions intensify regional differences in atmospheric pollutant emissions (APEs). Understanding the spatial disparities and drivers of APEs from road transportation is crucial to China's national efforts in atmospheric pollution control. This study proposes an integrative research framework to explore the spatiotemporal characteristics and driving mechanism of regional APEs (CO, SO2, NOx and PM2.5) from road transportation in Chinese provincial regions. Guangdong, Jiangsu, Shandong, Hebei and Zhejiang are the top five emitters. The kernel estimation analysis demonstrates that the gaps for CO and SO2 emissions across regions narrow and the overall emissions decrease, with the opposite conditions for NOx emissions. The spatial autocorrelation analysis verifies a positive spatial aggregation effect, with high-high aggregation in the east and low-low aggregation in the northwest. Gross domestic product (GDP) per capita and population are the promotive factors to emissions. The effect of APEs from unit vehicle is inhibitive, with strengthening effect on NOx and PM2.5 emissions but weakening effect on CO and SO2 emissions. The effects of intensity of vehicle use and development level of road transportation are opposite. More developed regions are greatly influenced by intensity of vehicle use, development level of road transportation and GDP per capita. Both the methods and results of this study can provide better decision-making support for national and regional APEs control policies targeting transportation sector.