The transport sector represents the largest oil consumer sector in the world and therefore one of the main challenges for climate change and energy security of supply policies. Improving energy efficiency in this sector is a matter of urgency. This report presents a concise overview of technical and non-technical measures that can be applied to improve energy efficiency in the transport sector as well as of policy instruments that may be implemented to promote application of these measures. Various options are discussed in the context of current trends and of short and long term environmental and economic objectives in the transport sector. Furthermore energy efficiency initiatives and relevant activities of various international organisations are mapped. The report was prepared as a discussion paper for the meeting of the PEEREA Working Group on Energy Efficiency and Related Environmental Aspects on November 9-10, 2006. PEEREA is a international working group involving 51 member countries under the umbrella of the Energy Charter (see: www.encharter.org).