This report provided an industry reference on the environment, fuels, and vehicles and support mechanisms for the UK public transport sector. It covered new low-emission engine and fuel technologies in the bus and rail sectors, and included: the current state of play regarding emissions reduction across the transport sector; modal shift and technological change to meet lower-carbon policies; EU and UK environmental policies, including those on low carbon, air quality and noise, for bus and rail, as well as the effects of private vehicle policy development and voluntary agreements; environmental reporting by public transport companies; a technical review of cleaner fuels and engine technologies (including exhaust after-treatment, electric and hybrid engines, and hydrogen and fuel cells); EU and UK support mechanisms, and UK fiscal policy, including discussion areas for policy and change.