Accessibility in European Peripheral Territories: Analyzing the Portuguese Mainland Connectivity Patterns from 1985 to 2020

The inner periphery European countries, as is the case of Portugal, are characterized by poor access to essential areas and services of general and social relations. Contextually, this paper aims to explore the linkages between inner peripheries, ultra-peripherality concepts, and the concept of accessibility from 1985 to 2020, in parallel with the analysis of some demographic trends in the same research period. Thus, the study deals with accessibility and the analysis of accessibility-related spatial distribution to represent the traditional core—periphery pattern, with the highest accessibility in the center of the mainland and west coastal area, and the lowest accessibility in remote regions. The results show that the distribution of the road infrastructure is not uniform in Portugal. Furthermore, the NUTS II regions of PT13 Lisboa e Vale do Tejo (the Lisbon region) and PT11 Norte (northern Portugal) have the greatest road per km2. The Lisbon region has the highest concentration of national roads globally, while the northern region has the highest concentration of municipal roads. These two regions are, by far, the most densely populated, encompassing about ¾ of the national population and GDP.