Transport is responsible for about a quarter of the European Union’s greenhouse gas (GHG) emissions. That is why it is crucial to evaluate the sustainability of fuels throughout their life cycle to be able to establish which ones are the most sustainable. This is the context in which the Biolca European project is set. Its aim it to produce a web tool that will allow the sustainability of the transport sector to be evaluated and improved. The new tool, which has already been designed and is currently in the testing phase, allows the environmental, social and economic impacts associated with the use of different sources of energy in the transport sector to be calculated (petrol, diesel, bioethanol, biodiesel, electricity, natural gas, LPG, kerosene). These impacts are calculated bearing in mind the whole lifecycle of these sources of energy from extraction, generation or cultivation right up to their use. That way, Biolca enables organisations in the transport value chain to take decisions when it comes to opting for one source or another. Likewise, it will be of tremendous help in shaping public policies on different levels to prioritise or promote specific sources of energy. Funded by the European Commission, the project is being led by Ekotek and has the participation of Tecnalia, Gaiker-IK4, Factor CO2, Cespa and Bilbao City Council. The tool, which is currently being tried out on the fleet of vehicles of the latter two organisations, has been developed within the framework of the LIFE+ project.