The recent enlargement of the European Union (EU) towards East Europe and the Balkans provides a common policy framework towards the promotion of socio-economic convergence of the 12 new member-states to the EU emphasizing the role of the transportation system. A system of indicators is developed in this paper in order to describe the new member-states’ transportation system in relation to the area’s socio-economic characteristics by comparing them to the transportation and socio-economic profile of the 15 pre-enlargement member-states. The analysis indicates relatively low levels of mobility for the study area combined with social and economic disparities. It also highlights a series of prospects that could contribute decisively towards the achievement of socio-economic convergence. Based on the experience gained by the development and application of the indicator system, the paper concludes with a series of propositions in order to enhance its contribution for the description of the features and the assessment of the impacts from the development of the new member-states’ transport system.