Transport infrastructure was one of the foundations of development and cohesion strategies in the European Union and elsewhere in the world. However, despite the considerable resources invested in its development, its impact on economic growth remains indefinite. In this paper the aim of the research was to examine the extent to which the transport infrastructure, represented by regional highways, contributed to the regional economic growth of the NUTS 2 region of the European Union. The analysis was carried out separately for the NUTS 2 regions in the EU-15 countries (developed) and for the NUTS 2 regions in the new EU-13 countries (underdeveloped). The impact of the infrastructure is analyzed, but in relation to other factors that may also condition economic growth (according to the availability of data, certain additional independent variables representing innovations and technology, as well as the socio-economic and institutional conditions of the region are included). The results of the regression analysis point to the conclusion that the development of transport infrastructure does not represent the "driver" of economic growth in developed regions and that the emphasis in the development policies of these regions should be placed on other factors (other independent variables which have shown statistically significance in the model). For underdeveloped regions (NUTS 2 regions in the new EU-13 countries), regression results show that the positive coefficient of the "traffic" variable is statistically significant, but only in the final step of the regression (which includes all four additional independent variables used in model). Because of this, and also because some of the additional independent variables in the model are statistically significant, it can be concluded that development policies in this group of regions also need to take into account other potential factors of regional economic development.