The experiences of cross-border cooperation (CBC), undertaken not only in Europe but throughout the world, have enabled areas to gain greater importance in recent decades at an international level, showing potential for integrative functions and joint development as exemplified by several CBC projects. The present paper assesses the impact of CBC projects by analyzing a protocol established in 2013 between the cities of Elvas and Badajoz, which induced the creation of the Eurocity Elvas-Badajoz. The paper kicks off with a critical review on territorial factors for success in CBC areas, considering the analysis of several case studies throughout Europe. The lessons learned, taken from the analyzed case studies, and the identified territorial success factors were used as assessment points for the investigation of the target study area, the Eurocity ElvasBadajoz. The investigation explores public participation perceptions towards the identification of what changes with respect to standards of life with the CBC project, providing the current state of affairs and identifying where to place efforts in order to reach sustainable development for the region. While being a transition area, it presents several opportunities for growth. These opportunities have not yet been object of analysis and debate with respect to lasting, sustainable successful growth. The present research enables the identification of several territorial factors for success in the study area, such as the connectivity/movement between cities and strong political commitment. From the identified critical factors, it was possible to highlight the importance of public transportation as a priority for achieving success in this CBC project.

Accessibility plays a major role in achieving sustainable transport, and therefore urban and regional sustainability. The urban public transport system promotes mobility and realizes a large part of urban movements. Moreover, improving accessibility in order to promote sustainable transport requires the application of new concepts and indicators as a powerful tool in the process of creating a balanced urban transport system. In this regard, one of the main goals of this research is to present an overview of the relevant accessibility indicators and assessment of accessibility in regional Cross-Border Cooperation (CBC) in order to transcendence challenges and obstacles for sustainable transportation in these regions along of Portuguese-Spanish border. This paper focuses on the accessibility of cross-border cooperation scenarios along the border regions of Alto Alentejo (Portugal) and Badajoz (Spain) where the Case Study Research Method (CSR) made it possible to recognize accessibility as a key factor in territorial success. Also, accessibility analysis can assess improvements as well as regional imbalances. In addition, this methodology can be used to identify missing links, which requires new investments enabling long-term sustainability.

Considering the complex dynamics, patterns, and particularities that peripheral and insular territories/regions present—e.g., as the fragility, they show to achieve a sustainable development and growth—a study that analyzes the land uses of this territories is seen as pivotal to identify barriers and opportunities for a long-term sustained development. Contextually, a general analysis was carried out through case study research methods covering those territorial typologies of the insular territory of Madeira Island, Portugal. The study, which was carried out through GIS mapping tools, enabled us to identify the land use changes in the last decades over the territory—allowing to establish a relation and identification of the associated barriers and opportunities presented by the territories to face the emerging sustainable development challenges. The study reveals the evident limitations of “ultra-peripheral” territories not only by the physical spatial dimensions but also by the difficulty to reconvert land uses. Thus, the main actors and their policies over the territory are even more relevant and need to be conducted in a more reasonable way—considering the fragility of this regions; such actions present higher impact over the territory and over their inhabitants’ life’s quality standards and finally on the long-term sustainability.

Spatial and urban planning processes regarding border cooperation have reached unprecedented levels in recent decades, not only due to their potential for territorial integration, i.e., infrastructure construction and planning activities worldwide. Bearing in mind the European project, for a united and strong network of nations, this scenario is more evident in European territories. In this regard, through multivariated analyzes of city cooperation on European border areas, it is possible to identify the factors that influence the territorial success and also a sustainable regional development and even their effects over the urban agglomerations. From the identified factors, the study pointed out one that is common to all cases: connectivity-movement between cities.

Political commitment and transparency have been previously identified as critical factors for territorial success, as well as factors which allow the achievement of stronger cohesion and sustainable growth of cross‐border cooperation projects and strategies. The present study is aimed at a more thorough analysis of these factors. Throughout the analysis and assessment of the European CBC case studies, where political commitment has been defined as a critical factor, political and economic transparency plays a key role. This analysis, which incorporates public and technical opinions, provides a better comprehension on how these factors influence the European panorama. It includes the key messages for policy‐makers when designing and implementing development strategies specifically tailored to the needs of these places.