1. Academic Tourism

There is a gap in the literature regarding the definition of academic tourism; however, it can be characterized as a stay of usually less than a year, spent for academic reasons, outside the usual environment of a particular individual, with the aim of completing an academic degree in a university or attending language courses offered by these institutions ^[1]. Adding to that, academic tourism can contribute substantially to the development of the tourism sector more broadly ^[2], since characteristics such as change, leadership and innovation are prevalent in academic tourism ^[3].

Academic tourism can be characterized by two aspects, related to domestic academic tourism, carried out by students who move to study within their own country, or with international academic tourism, in which students go beyond the borders of their own countries ^[4]. In addition, given its characteristics, academic tourism can be considered as more sustainable than conventional tourism because it has a greater relative economic impact than conventional tourism (i.e., it is more efficient), does not generate significant impacts on the environment, and contributes to socio-cultural sustainability (i.e., it enables the expansion of knowledge through the interrelationships between different students with different backgrounds) ^[5][6]. In this sense, academic tourism has a series of elements that distinguish it from traditional tourism, such as the length of stay, rental patterns of accommodation and the large consumption of local goods, while maintaining similarities with conventional tourism, such as standard choice of destination or frequency of sightseeing ^[7].

Ref. ^[8], when investigating the economic and non-economic determinants of academic tourism demand, using panel data from 31 countries during the period from 2000 to 2010, found empirical evidence that transport costs together with variables such as living standards and relative prices between different countries are determining factors for modeling demand for international academic tourism. In the same sense, the authors of ^[1], when evaluating the determinants of demand for academic tourism in Galicia, Spain, using a sample of 324 observations from a panel composed of students from 36 countries during the period between 2001 and 2009, found evidence that among the economic factors analyzed, only the cost of travel was significant to model the demand for academic tourism. With regard to the economic impacts of academic tourism, the authors of ^[7] point out that the economic effects of this type of tourism remain small and that its economic impact is mainly driven by student spending channels, according to an assessment using panel data from 29 European countries during the 2000–2016 period.

2. Transport and Regional Development

Among the multiple factors related to the attractiveness of a given destination, from a tourist perspective, accessibility is one of the factors that is of great relevance. Although a given region has important tourist attractions, such as beautiful natural landscapes, beaches and historic monuments, its success as a tourist destination depends largely on the transport infrastructure, which must be convenient, comfortable and safe ^[9]. It has also been found that tourists will be more likely to change their tourist destinations if they are inhibited in any way by inefficiencies in the transport system ^[10]. The transport infrastructure promotes easy access to tourist destinations in addition to enabling an increase in business activities in a given region, substantially impacting the living standards of its residents ^[11]. In this sense, the development of infrastructure and the sustainable development of a region are closely related, so that the infrastructure system is an important basis for the construction and implementation of the local development of a given region, exercising a direct influence on this development by bringing tourist opportunities to less frequented areas ^[12]. In addition, it is known that infrastructure is also an essential element for the development of the described function in the most valuable natural areas ^[13].

More exactly, tourist flows tend to be concentrated in areas that have a greater number of attractions and other well-developed objects of tourist interest; one of the criteria of great relevance for this concentration is the available infrastructure in which they are inserted. Transport can, in turn, be one of the fundamental elements for regional development, since an efficient transport system in all areas can favor the development of tourism in other less visited or internationally famous areas ^[14].

When assessing the importance of transport infrastructure in the attractiveness of a tourist destination, using panel data from 28 countries during the 1990–2000 period, the authors of ^[15] found empirical evidence that transport infrastructure has significant influence in the flow of tourism to a given destination.

Similarly, the authors of ^[16], when investigating the factors that impact the satisfaction of tourists in a city in Vietnam, found empirical evidence that, among other factors such as historical and cultural attractions, infrastructure services have a significant impact on the satisfaction of tourists. In the same sense, the authors of ^[17] identified, through an exploratory investigation using a sample of 155 tourists in Vietnam, that infrastructure services, together with the safety of tourists, are a factor of significant influence for the profitability of tourism companies.

Specifically, with regard to academic tourism, the authors of ^[18], when assessing the critical determinants of the selection of tourist destinations by students from countries such as Canada, Poland and Trinidad and Tobago, found evidence that the quality and efficiency of transportation services’ locations are determinant factors for the choice of students, being closely related to their ease of use and the costs associated with their use.

3. Mediators of Satisfaction and Loyalty to Metro do Porto

Social Responsibility has come to be seen as a key factor for companies to contribute to sustainable development and achieve competitive advantages. Corporate Social Responsibility consists of the voluntary adoption of policies, strategies and measures that contribute to a more equitable society and a less polluted environment. According to the authors of ^[19], Social Responsibility for companies can be understood as an investment that creates benefits for the company, society and the environment. In this way, Social Responsibility can be integrated as a policy or into the main business strategies, allowing the organization to improve its competitive advantage, which can be a relevant component to differentiate itself from the competition and maintain sustainable relationships with stakeholders ^[20]. In the wake of the understanding of Social Responsibility and its effects, as a strategy that fosters the growth of corporate profitability and stimulates the customer’s perception, the customer will look for companies whose products will be able to satisfy them and simultaneously involve social sustainability and environmental practices. In this way, Social Responsibility strengthens the company’s image towards customers and society. Implementing an SR policy is, therefore, relevant and essential for sustainable operations and the long-term development of a company. The adoption of good Social Responsibility practices is a differentiating and enhancing element of the image of companies, territories and tourist destinations in which they are inserted ^[21]. This sense of responsibility contributes to regional and local development and the image of tourist destinations with national and international tourists. To sum up, Social Responsibility is recognized as an ethical theory comprising the civic duty of individuals as well as their underlined actions to benefit the welfare of the society.

Within the concept of customer loyalty there are several academic and scientific works, which address the evolution and the different points of the concept loyalty as well as analyze the variables that foster Customer Satisfaction and Loyalty. According to several scientific studies, in the area of service marketing, which point to the importance of companies assessing the determinants of Customer Satisfaction and Loyalty, the authors of ^{[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]} also argue that customer loyalty should be seen as a commitment established in the mission and culture of business organizations. Therefore, organizations must develop their operations without neglecting Social Responsibility, Quality of Service, Perceived Value, Corporate Image, and Customer Satisfaction since these studies concluded that these dimensions contribute positively to the promotion of customer loyalty.

Thriving companies balance profitability and profit objectives with social objectives, incorporating social and environmental concerns into their main operation, policies and business strategy ^[39]. The present work aims to show the response of a transport company to meet the needs, when the company’s image can be environmentally friendly and socially responsible and, consequently, bring reflections at the level of the destination for academic tourists.