These days, climate change issues and their impacts on the economy, social and natural system of countries have become the main concern of worldwide, even for those countries that are facing major economic problems. These issues arise from the combustion of fossil fuels. One of the major contributors to global CO2 emission is the transport sector. Therefore, in order to identify the trends and characteristics of transport carbon emissions this study reviews the relevant literature significantly; and decomposes carbon emission in this sector in 7 top transport CO2 emitter countries by applying the logarithmic mean Divisia index (LMDI). The results indicated that, during 2000–15, transport carbon emissions increased in the United States, China, India, Canada, Russia, and Brazil whereas decreased in Japan. Hence, in the majority of these countries, energy conservation strategies were not successfully implemented during the study period. In the majority of countries, the main contributor to CO2 emission reductions was carbon intensity, whereas the main drivers of CO2 emission increases were electricity structure and economic output effects. Reductions in carbon emissions could be achieved by further optimizing energy structures, limiting the private vehicle population. A set of policies and regulations, from demand-side and supply-side, must be implemented to be effective in reducing GHGs emissions. •The study analyzes the patterns of CO2 emissions in 7 top transport carbon emitters.•It uses two methodologies, a review of literature and carbon emission decomposition.•Implementing a set of climate change policies can reduce carbon emission.•The United States and China were the main contributors of transport CO2 emissions.•The main contributor to CO2 emission reductions was carbon intensity.