A new European concept - Green Corridors - has been introduced to the EU member states defining them as long-distance freight transport corridors where advanced technology and co-modality are used to achieve energy efficiency and reduce environmental impact. Key objectives of the thesis are the development of the European concept of Green Corridor regarding the theory of sustainable transport and EU transport policy, the implementation level of the concept within the East-West Transport Corridor and the relation of a’ greener’ East-West corridor to sustainable transport solutions in the Baltic Sea Region as well as towards more sustainable transport system in the EU. The analysis of the sustainable transport systems and the concept of green transport corridors have been applied to the East-West Transport Corridor in the BSR through the trans-national cooperation project EWTC II, as a case study with a review of EU documents and academic literature as well as research into the documentation of the project.