This knowledge showcases prepared by ADB outlines the key issues that affect counting of carbon emissions, measurement criteria for data and indicators, and addressing carbon emission through various surveys and approaches. It was felt that there is little information on the impacts of global transport policies and measures, making it hard to measure changes in fuel economy, local emissions, and vehicle use. Counting carbon in transport projects depends on who is counting. The agents might be third-party donors who estimate the CO2 implications of transport-related projects.