The goal of Amitran is to define a reference methodology to assess the impact of Information and Communication Technologies in traffic and transport on CO2 emissions. This methodology is intended to be used as a reference by other research, demonstration and deployment projects and addresses different modes for both passenger and freight transport through a comprehensive approach. The aim is to contribute towards more robust decision-making by bodies investing in ITS, assisting them in more effectively attaining environmental policy goals. Although the approach focuses primarily on road transport (as the majority of the ITS applications cover this mode), it also covers transport by rail, inland waterway and short sea shipping.