What are the stimulants on transportation carbon dioxide emissions?: A nation-level analysis

The transportation sector is the second-largest contributor to CO2 emissions globally. To develop a low-carbon country, identifying factors influencing transportation CO2 emissions on a country-by-country basis is necessary due to differences in travel behaviors and transportation infrastructures. This study identifies the CO2 emission stimulants across 145 countries. The first analysis uses stepwise and robust regressions to provide a holistic perspective. The second analysis employs the Least Absolute Shrinkage and Selection Operator (LASSO) regression after categorizing 145 countries based on their economic levels and geographical regions to obtain more detailed results. An additional LASSO regression involves grouping countries based on their OECD memberships and economic levels. The findings suggest that socio-demographics, travel characteristics, and logistics have distinct impacts on CO2 emissions at different economic levels of countries. This study reveals strong correlations between the increased share of cycling and decreased CO2 emissions, especially in all developed countries and Asian developing countries. In most countries, higher gasoline prices are associated with lower CO2 emissions. Moreover, the rise in electric vehicle usage is contributing to lower CO2 emissions in developed countries. These findings contribute to the global efforts to address transportation-related carbon emissions at the national level.