Mobility is one of the most important key factors that determine economic development and growth in most modern countries all over the world. Therefore, investments in infrastructure can have multiple effects when it comes to economic and social growth. What is more, economic development is directly associated with quality of life, as people tend to satisfy their advancing need for mobility with the aid of transport infrastructures. Transport infrastructure is internationally considered as an instrument of regional policy, on a national level, but their exact contribution to even regional disparities is not yet determined in the literature. Although a high quality transport system is not sufficient by itself for the development of regions, it assists in bypassing obstacles and creates the conditions for their development. Moreover, it does not create significant long-term regional changes. Egnatia Motorway is a recently constructed infrastructure project in the northern Greece and it is a part of the Trans - European Transport Network E-90. This major infrastructure project enhances the connectivity of the cities that are located across the northern part of the country while they are becoming more accessible to other greater urban agglomerations. This is achieved by connecting the reference area with the central part of the country. The aim of this paper is to identify and evaluate the impacts of the project with regards to sustainability. Sustainability is a multidimensional term, when combined with economic prosperity and social cohesion. Besides, increased accessibility is positively associated with regional development, but this is not the only factor that determines that. In particular, it will focus on whether the role of the local economies, of the different scale urban areas Egnatia crosses, has been strengthened or weakened when raised on intra-region level. For that purpose, the paper focuses on a case study of three different types of urban centres; Thessaloniki, a metropolis city, the medium scale city of Kavala and the smaller, rural city of Grevena. Although it seems to be obvious that there is a relationship between economy, urban growth and society, this research will be a tool which will help understanding how these concepts are related.
