Identifying Processes of Smart Planning, Governance and Management in European Border Cities. Learning from City-to-City Cooperation (C2C)

Abstract

Nowadays, especially in a European environment, it is almost given that border cities cooperate, or should cooperate. Nevertheless, several obstacles are jeopardizing the cities cooperation prosperity. Therefore, the understanding of most of the factors and processes possible involved in the success or failure of Cross-Border Cooperation (CBC) strategies and projects are pivotal to seek long-lasting territorial sustainability. Contextually, the study enables to identify three most influential factors and processes that should be considered to achieve territorial sustainability of CBC projects of City-to-City Cooperation (C2C) from a political-strategic perspective, being: Connectivity—movement between cities; political commitment; and the developing of common planning master plans.

1. Introduction

The times we are living need methods and opened and integrative politics to face the problems and needs of the territories. Solutions to these problems depend on social and economic signs of progress that can only be achieved as a common goal of the countries: Freedom, sovereignty, cooperation, social, and territorial cohesion, without forgetting sustainability [1,2,3,4,5].

Moreover, such challenges and impacts are even more evident in borderlands [6,7,8]. Therefore, the understanding of most of the factors and processes, and also from different perspectives, which are possible involved in the success or failure of Cross-Border Cooperation (CBC) projects and strategies are pivotal to seek long-lasting territorial sustainability.

In this regard, eleven European cities, were selected and therefore, the public and experts’ perceptions were analyzed.

Contextually, the study aims to give an answer to the following research question: Which are the factors and/or processes involved in the long-term territorial sustainability of Cross-Border Cooperation (CBC) strategies and projects of City-to-City Cooperation (C2C) from a political-strategic perspective?

Therefore, the present study allows a better knowledge for the involved actors and decision-makers of how border cities cooperate, and which processes they use to achieve success in their CBC projects and strategies. In this regard, the present study is based on exploratory methods. These methods allows us to extract the perceptions of the involved in the CBC projects under analysis. The study population consists of the cities’ population and experts’ who expressed their views on the past and future of the CBC project of his cities is involved in, as well as the main actors of these CBC projects.

In this regard the study starts with the present introductory chapter, followed by a brief literature review regarding the common planning process at the light of the EU integrative perspective, a methodological approach regarding the used methods on the experimental part of the work, the results and their consequent discussion and conclusions, as well as a closing chapter focusing on the study limitations and future research lines.

2. The Planning Process—From an Integrative European Perspective. A Brief Overview

This section intends to highlight the potential planning, associated with common planning and European territorial integration policies, to achieve sustainable development in borderlands.

As a starting point, it should be considered that 56 countries in the EU have no direct instructions or provisions enforcing, or even a defined plan for spatial planning—territorial management still falls under member-states’ jurisdiction—under the principle of EU “subsidiarity” [9]. According to Rabé, Toto, and Dhima [10]: “While this is so, it is equally clear that the EU’s indirect role in spatial planning is steadily increasing, mainly through sector policies particularly in the areas of regional policy, rural development, environment, and transport. Another way in which the role of the EU is indirectly increasing in spatial planning is the principle of territorial cohesion”.

Moreover, it also should be highlighted the EU Cohesion Policy, such as: The 2007–2013 program, the initiatives European Spatial Development Perspective (ESDP) since 1999, the European Spatial Planning Observation Network (ESPON), or even the European Territorial Cooperation (INTERREG); these initiatives been so relevant in terms of development in EU territories [11,12,13]. Furthermore, the ESDP establishes five means for their implementation: (i) Application via EU regulatory oversight; (ii) via member states inter-cooperation; (iii) via borderlands and regional cooperation; (iv) application of the ESDP in member states; and (v) application through international cooperation—i.e., pan-European. In fact, ESDP represents the most relevant policy document for EU guidelines in development [12]. According to Rabé, Toto, and Dhima [10] and Loures et al. [9], the ESDP is: “(…) a new dimension of European policy (…) since for the first time the EU was starting to pay explicit attention to territorial planning as an instrument to achieve broader social and economic goals”. One of the main goals of ESDP was to clearer territorial impact orchestration of EU policies, which could be divided vertically and horizontally, respectively: (i) Across the different sectors (ii) across the levels of government and administrative boundaries [9,12]. Based on the main goals of EU policy, the ESDP follows the same objectives, operating on three main pillars: (i) Cohesion; (ii) conservation of natural resources and cultural heritage; and (iii) a more balanced competitiveness of the European territory. Therefore, in order to meet these goals, the ESDP focus on three key spatial development policy objectives: (i) Development of a polycentric and balanced urban system and strengthening of the partnership between urban and rural areas. This implicates overcoming the outdated contrast between city and countryside; (ii) promotion of unified transport and communication concepts which support the polycentric development of the EU territory and are a critical precondition to allows European territories to seek their integration into the Economic and Monetary Union. At a regional scale, some measures should be considered; and (iii) development and preservation of natural and cultural heritage through smart management. Therefore, it will contribute as for the preservation and deepening of regional identities as for the maintenance of the natural and cultural diversity of the European cities and regions in the next decades [14].

From the ESDP, another EU planning tools have been created—i.e., the European Spatial Planning Observation Network (ESPON) [9]. Regarding ESPON, this project aims to provide a policy for the support of the development and also to create a European scientific community in the theme of territorial development and growth in EU territories [10]. According to ESPON [15]: “Its main goal is to increase the general body of knowledge about territorial structures, trends, perspectives, and policy impacts in the enlarging European Union”. Therefore, ESPON is a pivotal tool for planners and main-actors in the planning processes within EU space—providing the technical and scientific knowledge needed for the implementation of those policies [16,17].

Moreover, these policy objectives seek a sustainable solution to the planning of areas such as infrastructure and transport planning, agriculture, and rural development, as well as to environmental issues—bearing in mind the particular situation of each region [9,11,18,19,20].

Here it also should be highlighted the INTERREG initiatives and programs. The INTERREG is the first instrument to sustain cooperation across sovereign borders within EU territories, and the program is financed by the European Regional Development Fund [9,11]. In fact, many of the ESDP policy priorities have also been addressed using funds of spatial planning projects involving partners from different countries via the INTERREG Initiative [9,11]. The INTERREG focus on three main territorial levels regarding the spatial planning agenda: (i) CBC projects, involving geographically contiguous border regions; (ii) transboundary initiatives, through large multinational spaces; and (iii) interregional initiatives and programs, among non-contiguous regions across the whole territory of the EU [9,11]. Bearing in mind these three levels, it is possible to understand the strict connection and relevance they have over cooperation on regional and spatial planning along with other economic growth issues regarding regional policy [9,21]. In fact, the Commission of the European Communities [22] states the following regarding the territorial cohesion: “Territorial cohesion becomes a key element of promoting stronger integration of the territory of the Union in all its dimensions, and cohesion policy supports the balanced and sustainable development of the territory of the Union at the level of its macro-regions and reduces any barrier effects through cross-border cooperation (CBC) and the exchange of best practices”.

Furthermore, the powerful relationship between planning and cohesion policies within EU is reinforced by the efforts of DG Regio (Commission Directorate-General for Regional Cohesion), which has a leadership position on European spatial planning initiatives [21,23,24,25]. In fact, in European urban territories, one of the tendencies is to focus on improving competitiveness through clustering, networking, as well as fostering a more balanced development between the most successful EU economic urban agglomerations and their networks [23,24,25,26,27,28]. According to Rabé, Toto, and Dhima [10]: “Priorities are promoting entrepreneurship, local employment, and community development and measures to rehabilitate the physical environment, redevelop brownfield sites, and preserve and develop historical and cultural heritage”. By the other hand, if we focus on the European rural areas and according to Loures et al. [9]: “the member states should support economic regeneration by ensuring a minimum level of access to services of general economic interest, to improve conditions in rural areas and limiting outmigration. Besides, the priorities include the investment on infrastructure connectivity to the cities centers and to the European networks; creating an integrated approach to tourism sustainable growth; investing in development poles in rural territories—i.e., small- and medium-sized towns; and developing economic clusters based on endogenous resources through the use of new information technologies [10,14].

2.1. Sustainable Common Planning

Through the previous section, it was possible to present a brief overview of International integrative projects, programs, and strategies related to development and growth related to Cross-Border Cooperation (CBC), in EU borderlands territories. Nevertheless, we should also look, briefly, to the concept and objectives of the so-called Sustainable Planning.

The sustainable development is based on the harmony of three spheres: (i) Economic; (ii) social; and (iii) environmental [5,29,30]. In this regard, these three dimensions aim to achieve harmony among them. Therefore, when a project, a strategy or a synergy achieve it, we can say we achieve sustainability or sustainable development or growth [5]. The wide use of the concept of sustainable development starts in the after of the United Nations conferences on Environment and Development. There, it was also established as a new world paradigm after ‘Our Common Future’, in the final report of the Brundtland Commission [31,32,33].

Sustainable development is frequently understood as: ‘The development that meets the needs of the present without compromising the ability of future generations to meet their own needs’ [32]. In fact, the Brundtland Commission concluded that this is the most accepted as a definition of sustainable development, however it is often seen as vague to provide any operational value [34].

Bearing in mind these principles, when it is related to common planning in a border scenario—i.e., through a program, initiative, or project; the same sustainability principles should be used and extrapolated to the specific area of intervention.

Contextually, two scales of action, the regional, and local, will be briefly addressed in the following sub-sections.

2.1.1. The Euroregions

The Euroregionalization is a special CBC form and its essence is the cooperation mainly on a regional or local level, over the borders two or more countries. It realized by local communities of common interest. In practice, it focuses rather on public and non-governmental initiatives. The CBC in entrepreneurship is more weakly supported by European Union policy and public funds and it does not develop so fast [23,35,36,37]. According to Kurowska-Pysz, Castanho, and Mora Aliseda, [38]: “Euroregionalization means that solid, institutional forms of cooperation are introduced on a regional or local level, through the creation of, among others, associations. Their participants are mainly: Local authorities, regional authorities, non-governmental organizations, public institutions, schools, and universities. Euroregionalization is the highest degree of institutionalization of CBC structures, and its consequence is the emergence of Euroregions but it develops also according to individual interests of partners involved in CBC”. In fact, Euroregion is a territory located on the periphery of two or more sovereign states, which concept is based on a formalized CBC, on the common objectives of governments and public and private institutions and other entities operating on its territory. It has the geographical specificity and it is a form of institutionalized cooperation of the border regions of different sovereign states, taking place in full respect of national borders and laws in force in the territories of the countries involved in the creation of the Euroregion. The main goal of the Euroregion existence is the implementation of CBC, treated as jointly taken measures to strengthen and foster neighborly relations among territorial agglomerations or authorities within the Euro-regions countries. Besides, the euro regions’ activities should be based on sustainable common planning, as well as the conclusion of agreements and arrangements necessary for the adoption of implementation of such plans [35,36,37,38].

2.1.2. The City-to-City (C2C) Cooperation

Another special type of CBC that is increasing is the so-called City-to-City Cooperation (C2C). Even if it is increasing, C2C cooperation is not a novel phenomenon. C2C was started, and evolved, in European territories. In the C2C experiences ongoing, mainly in developed countries, the local governments usually define the guideline and contents of it [9]. In this regard, the primary international relations between local governments in European territories remount at the period of the post-War (1950s)—where the Council of European Municipalities and Regions, foster these transboundary synergies at the local level to provide more cohesion and union to Europe [39].

In the United States of America (USA) this transboundary development cooperation was gaining momentum in the 1970s, however, in the American scenario, this development was characterized by the total inexistence of formal regulations. After this period, a new trend of international relations of local governments became visible in the 1980—i.e., the efforts carried out by the local authorities united themselves against the apartheid in South Africa—by the United Kingdom, the United States, and the Netherlands, among others sovereign nations [39,40]. Regarding the Asian continent, the best examples could be found in China. According to Xian, Chan, and Qi [41]: “China has undergone economic and political restructuring in the post-socialist era under the background of globalization. At the same time, its provincial governments have mobilized various forms of booming North–South C2C within their respective jurisdictions during the last 10 years”.

Contextually, the experiences of CBC, are a worldwide phenomenon—i.e., the CBC projects between the Central and North America (USA-Mexico), in Asia (China-India), in the South America (Argentina–Chile or Brazil–Bolivia), among many other examples, that fosters the creation of a global network of relationships among people and nations [7,42,43,44,45,46,47,48].

In fact, these networks have been worldwide recognized by the planners, main-actors, and decision-makers in the planning and development field, as pivotal features that enable the introduction of new development challenges and paradigms into the next planning activities [9]. Thus, the set of systems and policies of the EU planning strategies as the case of the extent of the planning system, the extension, and the type of planning at the national and regional level plays a critical role [49,50]. According to Zhou et al. [51]: “It has redefined the role of the public and the private, maturity and integrity of the system and the distance between the intended objectives and the results actually obtained - dividing traditional planning mainly into four types, including regional economic planning, urban planning, comprehensive planning, and land use planning”.

Therefore, the shown resilience of the CBC to adapt to new scenarios depends largely on the used processes and their management—i.e., Euroregions, and C2C planning [3,4,5,6,7,8,9].

3. Materials and Methods

The present study required the use of several methods throughout research, including indirect and direct research methods and tools. The author dedicated a significant amount of time and attention to the development of a methodological framework. The methodological approach was divided into four main phases, ending with the identification of processes of smart planning, governance and management for territorial success in border areas (Figure 1). The phases were as follows: Data collection, case study selection criteria, analysis of case studies, and the processes and factors identification. Therefore, data for the study was collected through previous analysis of the selected sites, by analyzing the process of planning and design of each case study, and even through talks and informal interviews with technicians, experts, main actors and stakeholders of the transboundary cooperation process. Informal interviews and talks were engaged to identify the most relevant issues that should be answered throughout the present research, as well as the interest in this kind of study. Throughout the literature review, it was possible to cover a range of issues, considering not only the state of the art regarding the EU integrative CBC process but also the CBC at regional and local scales.

3.1. Case Studies Selection

Considering the purpose of the study eleven case studies were selected (Figure 2). Therefore, the case study selection criteria were the following: (i) cities must have done previous work on CBC; (ii) the CBC project should demonstrate forethought on the political-strategic sphere; (iii) the distance between cities could not be greater than 60 km; and (iv) at least one of the cities should have 20,000 inhabitants. In this regard, through the assessment of previous analysis of the selected case studies, as is the example of the study of Castanho et al. [7], it was possible to identify which cases meet the established criteria.

3.2. Surveys and Sampling

The research was been projected to residents, experts’ and technicians of the case study areas. The questionnaire was composed of 2 sections. The first one with a total of five questions—closed-up questions through a Likert scale assessment method. And the second with multiple-choice questions.

The sampling was composed of 200 inhabitants of the case study areas and 22 experts’ working or living in the area or its surroundings. The surveys were implemented between 2016 and 2017.

3.3. Data Analysis

After collected, the data obtained from the questionnaires was organized using in a first place the Microsoft Office Excel spreadsheet, and then statistically analyzed using the Statistical Package for Social Sciences (SPSS). Contextually, descriptive statistics were used by the author. Moreover, and bearing in mind the purpose of the research advanced statists as a Principal Components Analysis (PCA) were also applied.

4. Results

Contextually, the results in the following are provided by: (i) Indirect analysis—through the analysis of the literature review; and (ii) direct analysis—through the questionnaires, along with the informal interviews and talks with the technicians, experts, main actors, and decision-makers of the CBC projects.

4.1. Indirect Analysis

Throughout the case study analysis, many data was collected, to acquire a strong understanding of the most relevant issues that should influence the success of the CBC projects (

Table 1. Case studies analyzed topics [7,52].

Case Study	Population	Distance between Cities (Km)	Strategy of Territorial Development	Border Typology	Languages	Currency	GDP/Capita (euros)
Aachen	241,000	40	EMR 2020	Schengen Area	German	EUR	24,000
Liège	197,000				French		22,000
Strasburg	275,000	5	Cross-Border White Paper	Schengen Area	German	EUR	27,000
Khel	34,000				French		33,000
Vienna	1,740,000	55	Centrope Strategy 2013	Schengen Area	Austrian, German, Slovakian	EUR	50,000
Bratislava	415,500						37,000
Chaves	41,200	25	Agenda 2008	Schengen Area	Portuguese	EUR	13,000
Verín	18,000				Spanish		22,000
Geneva	192,000	10	Agglomeration Project France—Vaud–Geneva	Schengen Area	French	CHF	61,000
Anemmase	33,000					EUR	23,000
Nice	345,000	15	Nice Côte d’Azur	Schengen Area	French	EUR	28,000
Monaco	37,000						52,000
Saint Louis	20,000	4	IBA Basel 2020	Schengen Area	French	EUR	26,000
Basel	174,000					CHF	87,000
Tuy	17,000	3	INTERREG/POCTEP	Schengen Area	Spanish	EUR	22,000
Valença	14,100				Portuguese		13,000
Newry	26,800	20	Twin City Newry-Dundalk	Outside Schengen Area	Irish	EUR	58,000
Dundalk	31,100				English	GBP	53,000
Haparanda	9500	5	HaparandaTornio	Schengen Area	Swedish	SEK	36,000
Tornio	22,000				Finnish	EUR	24,000
La línea de la Concepción	63,300	3	-----------	Intercontinental	Spanish	EUR	16,000
Gibraltar	30,000				English	GBP	34,000

). Therefore, general settings were analyzed as: Statistical data for the population of the cities; data relative to the distance between the cities of these border cities; the ongoing strategy of territorial development; the border typology; the used languages, currencies; and the GDP per capita.

4.2. Direct Analysis

To explore the public perceptions, five-question closed-up questions, through a Likert scale assessment method, were addressed to the cities’ inhabitants. The participants were asked to address the agreement level with five sentences, where: 1—totally disagree; and, 5—totally agree. Therefore, the majority of the sentences (I, II, and IV) the selected answer was 3 in 5 points Likert scale. Regarding sentence III, the higher value was found in the number 4 in a 5 points Likert scale. Also, it should be highlighted sentence V: “The implementation of the cross-border cooperation strategy enabled an increase in job opportunities for both cities?” where the residents’ totally agree with this sentence—being the highest value found in the number 5 in a 5 points Likert scale. The results described are shown at

Table 2. Likert scale questions.

Sentences	Agreement Level
	1	2	3	4	5
I	3.1	28.1	34.3	18.7	15.6
II	6.2	15.6	37.5	25.0	15.6
III	18.7	25.0	18.7	31.2	6.2
IV	18.7	21.8	31.2	18.7	9.3
V	6.2	9.3	28.1	25.0	31.2

(I) There is generally a duplication of equipment in the area of cooperation of both cities; (II) Even if there is an increasing cooperation between cities, regarding services and infrastructures, I still feel the need to seek services outside their influence area; (III) There is a high quality of data sharing and cooperation between both Cities at the planning level; (IV) There is a high quality of data sharing and cooperation between both Cities at the services level; (V) The implementation of the cross-border cooperation strategy enabled an increase in job opportunities for both cities.

.

Besides, a multiple-choice question (question a,

Table 3. Multiple-choice questions (a and b).

Questions	% of Participants Choice
	a	b
Enhance connectivity—Movement between cities	13.3	17.7
Promote the development of a strong territorial strategy	6.6	2.2
Promote strategies for no equipment duplication on nearby areas	4.4	4.4
Increase the sense of belonging	6.6	4.4
Benefit from similar equipment utilization rate—Euro citizenship	2.2	2.2
Increase the opportunity to access European funds	4.4	2.2
Proximity to socioeconomic flows	4.4	2.2
Raise local planning and life’s quality standards	4.4	2.2
Promote strategies for reducing the loss of young citizens	8.8	6.6
Promote development of common planning master plans	11.1	17.7
Political commitment	13.3	15.5
Citizen involvement from the beginning of the process	6.6	6.6
Transparency and commitment between cities	2.2	13.3
Creation of a specific and well-advertised Eurocity plan	11.1	2.2

a—Please identify which are in your opinion the 3 most relevant factors for territorial success in Cross Border Cooperation projects? b—Please identify which are in your opinion the three main challenges cities need to consider in cross-border cooperation?

) was used, where the participants should identify the three most critical factors for territorial success in CBC projects. Furthermore, the participants were also asked to answer to another multiple-choice question (question b, Table 3), where they should identify the three main challenges cities need to consider in CBC environments.

Through a PCA, fourteen variables were analyzed (

Table 4. Analyzed variables/components through principal components analysis.

Analyzed Variables/Components	% of Variance
(i) Connectivity—movement between cities	1.86
(ii) Development of a strong territorial strategy	−0.51
(iii) Strategies for no equipment duplication	−0.63
(iv) Sense of belonging	−0.31
(v) Euro citizenship	−1.16
(vi) Access European funds	−0.83
(vii) Proximity to socioeconomic flows	−0.83
(viii) Local planning and life’s quality standards	−0.83
(ix) Reducing the loss of young citizens	0.20
(x) Common planning master plans	1.54
(xi) Political commitment	1.66
(xii) Citizen involvement	−0.11
(xiii) Transparency and commitment between cities	−0.15
(xiv) Eurocity advertisement	0.14

). The variables (i), (x), and (xi) are the three that could be considered the principals’ variables. In the first place, we have the variable (i), followed by carriable (xi), and in third place, we found the variable (x).

Moreover, the fourteen critical factors identified by Castanho et al. [7], were studied in order to isolate the ones that meets only the political-strategic theme. Therefore, it was possible to isolate 5 critical (

Table 5. Political-strategic critical factors.

P1	Strong territorial strategy
P2	Common objectives and master plans
P3	Stronger political commitment
P4	Political transparency and commitment
P5	Euro-city marketing and advertisement

and

Table 6. Political-strategic critical factors related with the case study.

Case Studies	Critical Factors
	P1	P2	P3	P4	P5
Aachen–Liège	X
Strasburg–Khel			X
Vienna–Bratislava		X
Chaves–Verín					X
Geneva–Anemmase			X
Nice–Monaco				X
Saint Louis–Basel		X
Tuy–Valença					X
Newry–Dundalk	X				X
Haparanda–Tornio					X
La línea de la Concepción–Gibraltar				X

).

5. Discussion and Conclusions

Throughout the analysis of Table 2, where the participants were asked to address the agreement level with the five sentences, it is possible to verify that none of the sentences receives a “totally disagree” highest value by the respondents’, however, only one sentence (sentence V) have received the highest value as “totally agree”. Therefore, and based on these results, the populations of the analyzed case studies believe that the implementation of the CBC project provides an increase in job opportunities for the cities within the C2C cooperation strategy. In fact, these results could be in part explained by the good results over the last years in the Central European C2C cooperation area of Vienna–Bratislava—i.e., the increasing on the GDP/per capita, the strong labor market and the consequent job opportunities, or the easier of access to services [53,54]. Moreover, it must be emphasized how the synergy between the territories of Austria and Slovakia have worked in a positive way to increase territorial cohesion and also to foster the level of development for both cities, not only on the regional and national scales but also at an European scale [54].

Even if none of the sentences receives a ‘totally disagree’ as the highest value, the results show that the inhabitants are not fully satisfied with the common planning strategy regarding the non-infrastructure duplication in nearby areas. However, the cities of Saint Louis-Basel presents one of the best examples of infrastructure’s sharing within EU territories, the EuroAirport [5]. The EuroAirport located in Saint-Louis and Hésingue (France), serving the cities of Basel, in Switzerland, Mulhouse in France and Freiburg (Germany)—in fact, this infrastructure answers a complex transboundary issue as is the case of the massive urban agglomerations settled in the region [55]. In fact, there is also the successful Spanish-Portuguese cases of non-infrastructures’ duplication of the carried out by the C2C cooperation between Chaves-Verín or Tuy-Valença—where the populations of both sides of the border benefits from the same discount rates in the cities’ public services as the natives [7,56,57].

Similar to what occurred with the non-duplication of infrastructures (sentence i), the inhabitants still feel the need to look for services outside their influence area—even if there is increasing cooperation between cities (sentence ii). Here, it is possible to understand how relevant the selected strategy is for territorial development. Therefore, the chosen strategy should be based on a smart planning process—i.e., focusing not only in a few problematic fields identified on the region but instead choose a strategy with a larger scope, aiming to answer more social, economic, and environmental needs existing on the territory. Contextually, there is the successful example of the C2C cooperation between the cities of Strasbourg–Kehl, where the defined strategy for territorial development (Cross-Border White Paper) have given answer to a wide range of projects and therefore meet the needs of the population [58]. In fact, in this region the searching for successful strategies for territorial development strategy are not a new phenomenon, according to Anderson [59]: “The commissions discussed projects such as Rhine’s top high-speed rail link, which began in 1992, and the second bridge in Strasbourg. Interest in the work of these commissions was increased by participating in the EC Interreg program and by abolishing border controls at the Rhine border”. Besides, in this specific case, some other factors also played a key role, as the example of the political commitment factor [59,60].

Also, for the sentence (iv), the above scenario repeats—once, the results show that the inhabitants are not fully satisfied with the quality of data sharing and cooperation between both Cities at the services level. Thus, the cities data and services should not only be shared but also coordinated. In this regard, could be given the case of the Portuguese-Spanish Euro-city Elvas-Badajoz-Campo-Maior, where an infrastructure of accessibility and connectivity connects both territories with none border control, however, the lack of transportation coordination between these two cities leads that this accessibility is almost inexistent [61,62,63]. By the other hand, there are also successful cases where data sharing and services coordination works smoothly—i.e., the case of the cities of Geneve-Anemmase or Copenhagen-Malmo [7,63].

By the analysis of Table 3, it is possible to understand the three most critical factors for territorial success in CBC projects (question a) for the respondents—which are in first place the enhance connectivity—movement between cities and, the political commitment; in second place promote development of common planning master plans and, the creation of a specific and well-advertised Eurocity plan; and in the third place promote strategies for reducing the loss of young citizens. Nevertheless, regarding the three main challenges cities need to consider in CBC environments (question b), according to the participants responses, they differ from question a, being: (in first place) enhance connectivity—movement between cities and, promote development of common planning master plans; (in second place): political commitment; and (in third place) promote strategies for reducing the loss of young citizens.

Here the three factors that repeat in the participants choices in both questions (a, and b) should be emphasized; the enhance connectivity—movement between cities, the political commitment; and to promote the development of common planning master plans. Bearing in mind the relevance of connectivity-movement between cities, some EU successful example of C2C cooperation are easily found—as the above-mentioned cities of the Benelux Region of Geneve–Anemmase, the Scandinavian cities of Copenhagen–Malmo [7,63], the Irish C2C cooperation of Newry–Dundalk [5], or the Central European cities of Cieszin–CeskyTesin [36], the East European cities of Oradea–Debrecen, Ruse–Giurgiu among several other cities along the Danube corridor [18,64]. Moreover, political commitment was also relevant to the participants of the analyzed cities. In this regard, it is possible to identify two similar cases—La Línea de la Concepción–Gibraltar, and Nice–Monaco. These two cases of C2C are formed by cities with “independent” governments, as the United Kingdom colony of Gibraltar or the Principality of Monaco, which face a similar issue related to fiscal transparency and commitment [65]. Besides, in those case studies exists a great unbalanced regarding GBP/per capita between Gibraltar and La Línea de la Concepción, as well as the same with Monaco and Nice; always favoring the city with an “own government”.

Regarding the relevance of developing common planning master plans, there is already several C2C cooperation projects within EU territories considering this typology of common planning—i.e., the cities of Vienna-Bratislava, Chaves-Verín, Tuy-Valença Haparanda-Tornio, or even Saint Louis-Basel. However, and based on the participants’ responses these common planning strategies should be increased to provide a better and wider answer to the populations’ needs.

Moreover, through the application of a PCA analysis (Table 4) it was possible to isolate the three most influential factors and processes that should be considered to achieve long-term territorial sustainability of CBC projects of City-to-City Cooperation (C2C) from a political-strategic perspective, being: Connectivity—movement between cities; political commitment; and, the developing common planning master plans.

In fact, these results are corroborated by the critical factors identified by Castanho et al. [7], however, when the political-strategic theme is isolated, the results differ. Therefore, and based on the research results, the main-actors, technicians, and decision-makers of the C2C cooperation projects should consider in their planning, management, and governance, the following planning principles are proposed:

• Choose strategies for territorial development with a wide-scope;
• invest in the common planning of accessibility and connectivity infrastructures;
• promote public participation in the development of common planning master plans;
• create policies for increasing the political and fiscal transparency.

6. Study Limitations and Further Research

Even if this research expands our knowledge and understanding regarding the most influential factors and processes that should be considered to achieve territorial sustainability [66] of CBC projects of City-to-City Cooperation (C2C) from a political-strategic perspective, worthwhile prospects of future research are still needed.

The EU panorama is evolving quickly leading to uncertainty of the patterns and directions of CBB C2C projects [67], and consequently the challenges. Therefore, a close monitoring process should be carried out. Although the selected case studies could allow us a relevant perspective of EU reality, if a larger sample of case studies as well as from other EU locations were selected, we can retain even more insights regarding this issue. Besides, the study focus only on the political-strategic theme, however, for the understanding of a complex process as CBC, other themes and perspectives should be studied.

As final remarks, further studies and researches, as well as close monitoring process of the CBC projects of C2C, are seen as pivotal to enrich this subject and expand our knowledge on the theme.