In Europe, limited information is available about the environmental characteristics of the vehicles stocks and of traded used vehicles in terms of vehicle's air pollutant and CO₂ emissions. In this context and on behalf of the European Environmental Agency, Ecologic Institute and Fraunhofer ISI explore available national and European data sources of vehicle stocks and trade throughout Europe and compile the available vehicle characteristics. Based on the available characteristics, the project team derives the environmental performance of vehicle stocks and traded used vehicles and assess  respective regional differences in the environmental performance of the vehicles stocks and of used vehicle trade flows.