What are the measures and strategies already taken by OECD countries to reduce or stabilise greenhouse gases from road transport? What frameworks exist to evaluate the impact and efficiency of these measures and strategies? And how effective are they? With the continued growth forecast in car ownership and distance travelled, what are the expected trends in CO2 emissions and their consequences for the potential achievement of the Kyoto Protocol? What models are available to predict the level of CO2 emissions? Are they useful? This report, which has been prepared by an OECD Working Group, uses a number of illustrative and pragmatic cases to provide important insights into these major questions.