Urban Problems—Diagnosis and Solutions

Abstract

The observation and analysis of reality have been a human activity for many centuries. Indeed, since the earliest of human cultures, people have been trying to understand their world and to improve its functioning. In the process, they have developed a number of different visions for the future. Urban space is characterized by its dynamism, exhibiting a fascinating blend of heterogeneity and susceptibility to rapid transformation. The primary objective of the present article is to present the urban problems and proposals for their solutions in a historical and global perspective. This work will demonstrate the historical context of diagnosing urban problems, drawing upon the literature from the past century. Depending on the geographical location, the potential exists for the sounding of an alarm or the drawing of attention to aspects that, for some, represent a reality that is difficult to overcome and for others, only a barely noticeable trend. It is asserted that this will ensure that, in the future, cities will function efficiently and be pleasant places to live. In conclusion, the development visions of cities will be presented and discussed. Visions of the future, as a reaction to the world around us, were and are a fundamental category of expectations and considerations, hopes and fears, and science and practice.

1. Introduction

Cities are places of residential function and concentration of education, public services, and business. They create economic development and are nodes of numerous networks, cultural phenomena, and carriers of civilization. These are also places where many social, economic, and spatial problems concentrate. We can see many urban problems in cities regardless of their location or national and cultural affiliation. That is why balanced and forward-looking actions for the quality of life of their inhabitants, environmental protection, and ensuring social and economic stability are essential.

In the preceding century, urban areas across the globe have experienced a series of substantial transformations, characterized by both dynamic growth and significant challenges. A range of phenomena has had a significant impact on the structure and functioning of cities. These include rapid urbanization, technological developments, climate change, as well as social and political changes. Although the process of global urbanization commenced in the early 20th century, it gained significant momentum in the latter half of the century, thus becoming one of the primary factors contributing to the urban challenges that are prevalent in the contemporary era.

One of the most significant phenomena related to urban development in the last 100 years has been intensive urbanization, especially in developing countries. According to data from the United Nations, the proportion of the global population residing in urban areas increased from 30% in 1950 to 58.3% in 2025 [1]. The incorporation of populations from other regions experiencing urbanization, in close proximity to cities and exhibiting solid functional relationships with them, results in approximately three-quarters of the global population being directly impacted by urban issues. In more developed regions and high-income countries, the index consistently exceeds 80% [1].

A critically important process taking place in metropolitan areas is suburbanization, which is developing very unevenly on a global scale. In western Europe and north America, it has been visible since the mid-19th century [2,3], while in central and eastern Europe, these processes have been visible only since the 1990s [4,5,6]. It is worth noting that suburbanization is not only the migration of people to the peripheries and changes in the level and quality of life of the population but also the relocation of companies [7].

As cities evolved into economic, political, and cultural hubs, they began to attract an increasing number of migrants from rural areas seeking improved living conditions. This phenomenon, while encouraging economic development, contributed to problems such as overcrowding, slum growth, and strain on urban infrastructure [8,9,10,11,12]. Urban overcrowding has been demonstrated to engender a number of quality of life issues [13,14,15]. The phenomenon of high human density in urban areas frequently gives rise to inadequate access to fundamental services, including but not limited to drinking water, sanitation, education, and healthcare [16,17,18]. Moreover, population growth in urban areas has resulted in the phenomenon of urban sprawl, defined as the expansion of urban areas into rural areas. This has had a detrimental effect on the quality of public space and has led to the destruction of natural ecosystems.

Another significant challenge confronting contemporary urban centers pertains to environmental degradation (among others: [19,20,21]). It is evident that, over the past century—particularly in the aftermath of the Second World War—accelerated industrial development, motorization, mass production, and consumption have collectively resulted in significant environmental challenges. The prevalence of issues pertaining to smog, air pollution, noise, water, and soil pollution has become a pervasive problem in many large cities, particularly in developing countries where the regulatory framework for emissions control and environmental protection was in its nascent stage.

It is becoming increasingly evident that climate change is also becoming an issue of increasing concern for urban areas. Rising temperatures, a reduction in green space, and an increased frequency of extreme weather events such as floods, hurricanes, and heat waves are having a serious impact on urban life. Urban areas, particularly those situated in regions susceptible to natural disasters, are confronted with the imperative of adapting to the consequences of climate change.

The phenomenon of social differentiation and economic inequality constitutes an additional crisis with which developing cities are confronted. Urban areas are witnessing an escalation in income inequality, resulting in significant disparities between affluent and impoverished neighborhoods [22,23]. It is frequently observed that individuals from economically disadvantaged social strata encounter limited access to adequate public services. This phenomenon has been shown to intensify feelings of marginalization and social disillusionment. The increasing prevalence of homelessness in metropolitan areas such as Los Angeles, New York, Mumbai, and São Paulo exemplifies this phenomenon [24,25,26,27]. In these cities, individuals experiencing homelessness frequently lack access to adequate shelter and healthcare services, highlighting a critical challenge in urban governance and social welfare.

It is crucial to show, as a main objective of this article, the urban problems and proposals for their solutions in a historical and global perspective. What is important is that, regardless of the location and local circumstances, cities around the world have faced similar problems over the last century, as recognized by international bodies of urban planners and architects. In conclusion, the problems of cities in the last 100 years demonstrate the complexity and multifaceted nature of the challenges of their development. On the one hand, cities have become centers of innovation and the economy; on the other hand, they face numerous difficulties that require rapid and effective solutions. It is imperative that sustainable development, which must encompass both human needs and environmental protection, is given due consideration in order to provide a solution to the challenges that are likely to arise in the future.

The work makes reference to earlier studies on urban issues, thereby situating its analysis within a broad historical and theoretical context. The authors make reference to fundamental urban planning documents, including the Athens Charter (1933), its subsequent amendments (1998, 2003), as well as the Machu Picchu Charter, New Urbanism, the Sofia Declaration, and the Toledo Declaration. A critical analysis of the manifestos reveals a continuity in the reflection on urbanization, while also pointing to an evolution in the approach to spatial planning. The focus has shifted from a mere functional division of the city to contemporary demands for spatial cohesion, sustainable development, and the protection of urban identity.

Consequently, the work not only perpetuates the tradition of urban planning research but also ingeniously advances it, demonstrating the pertinence of earlier diagnoses within the context of contemporary challenges such as suburbanization, spatial disorder, and the crisis of public spaces. This constitutes a valuable addition and development of the extant body of work in this field.

1.1. Literature

The extant literature on urban problems from a global perspective is quite extensive, especially when analyzing a time period of almost a century. It is evident that publications predominantly pertain to individual facets of urbanized regions, or alternatively, offer a comprehensive overview that is contemporary in nature.

The following publications, while not exhaustive of the subject of global urban problems, offer a valuable opportunity to acquaint oneself in detail with specific issues that are addressed in this work in a more general way. Some publications, like A New Theory of Urban Design [28], are an important contribution to the development of urban design theory, offering an alternative to the modernist trends that dominated at the time. Alexander’s approach, based on organic urban development and the consideration of social needs, has inspired much contemporary urban design practice, particularly in relation to sustainability and public participation in the urban design process. On the other hand, a publication by Ferguson and Dickens [29] focuses on whether community development can effectively address long-standing urban problems and which initiatives, based on social science analysis, can bring about real change. Worth mentioning is the article The rural-urban fringe [30], which is considered to be one of the first systematic studies of the urban–rural transition zone, describing the problems of cities in relation to their spatial development. Although it was published more than 80 years ago, the issues it raises remain relevant in the context of contemporary research on urbanization and spatial planning. The concept of the urban–rural transition zone is still relevant for understanding the dynamics of periurban development and the challenges of managing these areas. The urban sociology perspective was presented in the book Cities of Europe: Changing Contexts, Local Arrangements, and the Challenge to Urban Cohesion [31]. It is a comprehensive study of the transformation of western European cities in the context of socio-economic change at the turn of the 20th and 21st centuries.

The following publications are relevant to the study of urban problems in specific regions of the world. The article Problems of Urban Decline and Growth in EEC Countries: Or Measuring Degrees of Elephantness by Chesire [32] analyzes the variation in urban growth and decline processes in the countries of the European Economic Community (EEC). The authors propose a new methodology for assessing the health of urban areas, based on the analysis of socio-economic data from the 103 largest metropolitan areas in the EEC. In the book Urban Problems in Western Europe: An Economic Analysis [33], originally published in 1989 and republished in 2017, a comprehensive study of urban problems in western Europe from an economic perspective is presented. The authors examine the challenges facing cities in the context of economic, demographic, and political change and provide an in-depth analysis based on empirical data. For instance, the publications pertaining to urban issues in Germany and the United Kingdom are New trends in urban development and public policy in eastern Germany: dealing with the vacant housing problem at the local level by Glock and Häußermann [34] and Narratives of policy: the construction of urban problems and urban policy in the official discourse of British government 1968–1998 by Atkinson [35].

The publication that makes a significant contribution to the field of urban studies by offering an original perspective on the analysis of urban problems is Urbanization and Urban Planning in Capitalist Society [36] by Roweis and Scott. A critical analysis of how urban land is shaped and used in a capitalist context was described. The authors examine how market, political, and institutional mechanisms influence the spatial structure of cities, leading to concentrations of power and social inequalities.

The following publications are specific to the country under discussion, Urbanization and Urban Problems [37] by Mills and Song, which is an in-depth analysis of urbanization processes and related problems in South Korea between 1945 and 1975. It combines an economic perspective with an analysis of public policy, offering lessons relevant to developing countries. The following section will examine the challenges faced by cities in other countries, e.g., Urbanization and urban systems in India [38] by Ramachandran; Community and nostalgia in urban revitalization: A critique of urban village and creative class strategies as remedies for social ‘problems’ [39] by Barnes et al.—an Australian perspective; Urban Challenge in East Africa [40] by Hutton; Urban environmental problems in Nigeria: Implications for sustainable development [41] by Daramola and Ibem; and Managing urban growth and development in the Riyadh metropolitan area, Saudi Arabia [42] by Garba.

It is imperative to acknowledge the significant contributions of publications in the United States, which have played a crucial role in analyzing and addressing urban challenges. It is essential to begin by citing the seminal work of Jane Jacobs—The Death and Life of Great American Cities [43]. The next paper presents an interesting take on urban problems: From warfare to welfare: Defense intellectuals and urban problems in Cold War America [44] by Light. The book People, Plans, and Policies: Essays on Poverty, Racism, and Other National Urban Problems [45] by Gans is a collection of essays analyzing major urban problems in the United States, such as poverty, racism, urban planning, and social policy. A sociologist and urban planner, Gans takes a critical look at dominant narratives about cities and stresses the need for social and economic reform. The Ungovernable City: the Politics of Urban Problems and Policy Making [46] by Yates is an in-depth analysis of the structural and political causes of ineffective urban governance in the United States. Yates argues that the problem is not a lack of financial resources but is fundamental contradictions in the political and social structure of cities that prevent effective decision-making and implementation of public policy.

A range of subjects concerning specific urban challenges have been addressed in publications, including the book Traffic in Towns: A Study of the Long Term Problems of Traffic in Urban Areas [47] by Buchanan and Gunn, which is a contemporary edition of the famous 1963 report known as the Buchanan Report. The Buchanan Report has had a major impact on the development of transport and urban planning policy in the UK and other countries. Its recommendations have contributed to the development of pedestrian precincts, traffic restrictions in city centers, and the promotion of sustainable transport. Today’s challenges of urbanization, climate change, and sustainability make the report’s ideas still relevant and a reference point in discussions about the future of cities. The following themes are addressed in a similar manner, e.g., The urban transportation problem [48] by Meyer et al. The article Urban Mobility in the Developing World [49] by Gakenheimer undertakes an analysis of the challenges of urban mobility in developing countries. Gakenheimer identifies key problems and proposes strategies for improving mobility in the context of these regions.

A range of other issues are addressed in, e.g., Urban housing policy [50] by Grigsby; Urban sores: On the interaction between segregation, urban decay and deprived neighborhoods [51] by Andersen; Compact city, urban sprawl, and subjective well-being [52] by Mouratidis; Urban morphology and the problem of the modern urban fabric: some questions for research [53] by Levy; and Social exclusion, segregation, and neighborhood effects [54] by Musterd and Ostendorf.

Wu’s article Urban Sustainability: An Inevitable Goal of Landscape Research [55] is a call for the integration of landscape ecology with the science of urban sustainability. Wu emphasizes that research on urban landscapes is essential to achieving urban sustainability, although its exact definition may be subject to debate. Another publication is consistent with this line of thinking: A new urban ecology: modeling human communities as integral parts of ecosystems poses special problems for the development and testing of ecological theory [56] by Collins et al.

In order to achieve an overview of the subject, it was beneficial to utilize the following publications. The publication that provides an analysis of the issues faced by cities, as outlined in urban manifestos: Manifesty urbanistyczne, w poszukiwaniu współczesnego modelu miasta [57] by Majda and Mironowicz. The publication presents the evolution of urban planning as recorded in official documents over the last 80 years in Europe and worldwide. These plans have been formulated by urban planners, spatial planners, and architects and have been collated in organizations such as the Congrès Internationaux d’Architecture Moderne, the European Council of Town Planners, and the Society of Polish Town Planners. In addition, politicians have participated in various forums of the European Union and the United Nations.

The analyses in this article are based on the following publications, which are discussed in detail later in this article: Athens Charter (1933) [58]; Machu Picchu Charter (1977) [59]; Charter of the New Urbanism (1993) [60]; The Charter of European Cities and Towns Towards Sustainability—Aalborg Charter in Aalborg, Denmark (1994) [61]; The Lisbon Action Plan From Charter to Action in Lisbon, Portugal (1996) [62]; Towards Local Sustainable Development in Central and Eastern Europe in Sofia, Bulgaria (1998) [63]; New Charter of Athens (1998) [64]; New Charter of Athens (2003) [65]; Conference Inspiring Futures—Aalborg+10 (2004) [66]; Leipzig Charter (2007) [67]; Istanbul Supplement to the Charter 2003 (2010) [68]; Toledo Declaration (2010) [69]; The European Spatial Planning Charter (2012) [70]; The European Charter for Spatial Planning Barcelona, entitled Vision for Cities and Regions—Territories of Europe in the 21st Century (2013) [71]; New Leipzig Charter (2021) [72]; many activities and documents of the European Union that are part of the acquis relating to contemporary urban development; and a plethora of studies conducted by UN-Habitat [73] that have examined the myriad of challenges confronting global cities.

1.2. Aim and Research Methods

The research will describe the problems of contemporary cities. Depending on the geographical location, the discourse may be characterized by either the expression of alarm or the highlighting of aspects that, from a particular vantage point, are challenging to surmount, while from another, they are merely a barely perceptible trend. It is asserted that this will ensure that, in the future, cities will function efficiently and be pleasant places to live.

The main aim of the article is to present the findings of the research undertaken, which seeks to demonstrate the urban problems and proposals for their solutions in a historical and global perspective. In addition to the primary objective, the article also focuses on the implementation of cognitive and methodological goals. The cognitive objective is to present and determine the significance of knowledge pertaining to the primary urban processes and issues that exert influence on the progression of urban development. Furthermore, it is imperative to demonstrate the repercussions of the aforementioned processes and the responses of urban planners and authorities to them. The outcome of these processes is the contemporary modernizing process that is currently unfolding globally. A wide-ranging collection of documentation was presented, encompassing a comprehensive overview of prospective urban development projects. The methodological objective is achieved through the utilization of deductive analyses. Consequently, the research problems were addressed, or their solution was presented in a comprehensive and multifaceted manner. In practice, authors also employed the method of critical analysis of the available literature (serving to present the theoretical foundations of this matter).

In the course of the analysis of documentation pertaining to urban development issues and visions (for example, charters, declarations, urban strategies), a number of criteria were taken into account in order to facilitate the assessment of the content, objectives, and effectiveness of the documentation. Thematic scope was identified as a pivotal element, encompassing the extent to which documents address analogous issues and the significance accorded to specific subjects. A further criterion that was taken into consideration was the purpose and vision of the document. A range of perspectives on the future of cities was canvassed. An integrated approach was also analyzed. The central question pertains to the document’s comprehensive approach to urban governance, encompassing the integration of diverse policy areas within a unified framework. Another issue that was addressed was that of sustainable development. The authors’ objective was to ascertain whether the document under scrutiny promotes a balance between economic development, environmental protection, and social justice, and whether it attaches significant importance to environmental issues. In the course of the review, particular attention was paid to the implementation criteria, i.e., the presence of specific actions, recommendations, and timetables in the document.

The presented list of urban problems from a historical and global perspective, referring to numerous analyses, appeals, proclamations, or manifestos, has not been presented in such an extensive form in the scientific literature so far. The documents under scrutiny were selected with the express purpose of providing a comprehensive representation of expert opinion from a variety of fields, many of which were not affiliated with any specific nation state. It was imperative to demonstrate the international impact over a considerable number of decades. In order to obtain the results presented in this work, approximately 20 documents published over a period of almost 100 years were analyzed to show the historical context of diagnosing urban problems.

This article contributes to research on urban issues, offering an in-depth analysis of contemporary city challenges. It also provides knowledge on international documents and urban charters, which identify problems and formulate specific proposals and strategies for sustainable urban development. The publication makes a significant contribution to scientific discourse and planning practice, offering a comprehensive view of current urbanization processes and possible directions for their optimization.

The final results of this study will contribute to a better understanding of urban processes from a global perspective and will provide a basis for the future thoughtful development of cities. It is imperative to enhance the quality of life for urban dwellers, whilst also prioritizing environmental stewardship and ensuring sustainable social, economic, and environmental stability.

In conclusion, the development visions of cities will be presented and discussed. Specialists dealing with urban problems conceptualize future scenarios, investigate potential future trends, formulate visions for the future, and assess the likelihood of these scenarios and visions coming to fruition. The manifestos they create represent an articulation of a novel perception of space, a worldview that seeks to engender a shift in previous actions. The objective of this artistic endeavor is to illuminate the social and spatial predicaments that characterize urban environments. Visions of the future, as a reaction to the world around us, were and are a fundamental category of expectations and considerations, hopes and fears, and science and practice.

2. Results

2.1. Historical Context

The uncontrolled growth of cities in the 19th and early 20th centuries prompted urban experts to work toward creating coherent and transparent principles for the design and development of cities. The inaugural initiative of this nature was the establishment in 1928 of an international organization of modernist architects, known as the International Congress of Modern Architecture (CIAM). The objective of the initiative was to facilitate mutual consultation, consolidation, and promotion of the development of contemporary architecture. CIAM organized congresses, during the fourth of which (1933), under the chairmanship of Le Corbusier, the Athens Charter was adopted [58]. This document constituted a set of postulates concerning modern urban planning and residential architecture. In subsequent years, these postulates provided the starting point for considerations on the future of cities around the world. The document contained indications of the optimal development strategy for urban areas, emphasizing the importance of achieving high density combined with the establishment of highly efficient public transport systems [58]. The presentation outlined the primary functions of the city, including housing, employment, communication, and recreation. The fundamental postulates addressed the delineation of functional urban zones and the establishment of an orderly and salubrious environment conducive to habitation. The Charter was published in 1943, in anticipation of the conclusion of World War II, as a proposal of recommendations for architects tasked with the reconstruction of destroyed cities. In the post-war period, it exerted a profound influence on the development of housing as a manifesto of modernist urban planning and the theory and methodology of spatial planning at that time. Notwithstanding its considerable ideological saturation, the operation of the institution continued until the 1980s. [58].

Subsequent years witnessed the establishment of the Machu Picchu Charter (1977), which built upon the provisions of the Athens Charter while placing greater emphasis on intuition, mystery, and individual needs. The study’s primary assumptions pertain to urban areas and their respective regions, the progression of urbanization, the internal segmentation of cities, residential structures, transportation networks, the availability of urban land, natural resources and environmental degradation, cultural and historical identity, and technological development [59].

The New Charter of Athens was adopted by the European Council of Town Planners (ECTP) in 1998 at an international conference in Athens. The ECTP has decided to conduct a review and update procedure of the Charter on a quadrennial basis [64]. Consequently, following the update in July 2003, the subsequent document was designated the New Charter of Athens 2003 [65]. The subsequent amendment in 2010 resulted in the establishment of the Istanbul Supplement to the Charter 2003 [68].

The European Spatial Planning Charter (2012) emerged from the amalgamation of the Istanbul Supplement to the New Charter of Athens (2003), accompanied by supplementary content concerning spatial planning. This development is a consequence of the ongoing review procedure [65,70]. Concurrently, it was agreed that the following documents would be included: a set of “Perspectives” on the Charter, identifying the major challenges for each stakeholder group and an action plan for the next decade on the application of the principles set out in the Charter. The present Charter is founded upon the principles established in the New Charter of Athens of 2003, delineating the distinct characteristics and potential of the planning discipline. The objective of this initiative is to enhance the levels of trust, coherence, and solidarity within the domain of spatial planning practice [65,70].

In consequence of the update one year later, the European Charter for Spatial Planning Barcelona, entitled “Vision for Cities and Regions—Territories of Europe in the 21st Century” (2013), was established. This document comprises the vision and principles to which urban planners throughout Europe are bound [71]. An interesting contribution to the discussion on the nature and future of cities is the Charter of the New Urbanism (1993), the founding text of the New Urbanism Movement at the University of Chicago, “cultivating the thought of Krier, Jacobs, and Alexander”. The organization’s membership comprises individuals from a diverse range of civic circles, including public and private sector leaders, local community activists, and professionals from multiple disciplines. The manifesto advocates for sustainable urban development that is pedestrian-friendly and respects context [60].

The objective of organizing conferences on the eco-development of cities and municipalities was to address concerns regarding the protection, strengthening, and sustained development of these urban areas. Examples of such meetings include those of representatives of local authorities, associations of local governments, governments, the European Commission, and non-governmental organizations. The following conferences and agreements have been held in relation to sustainable development in the localized context: The Rio Summit in Rio de Janeiro, Brazil (1992); The Charter of European Cities and Towns Towards Sustainability—Aalborg Charter in Aalborg, Denmark (1994); The Lisbon Action Plan ‘From Charter to Action’ in Lisbon, Portugal (1996); and ‘Towards Local Sustainable Development in Central and Eastern Europe’ in Sofia, Bulgaria (1998) [74].

The following conferences were held: the Hannover Call of European Municipal Leaders at the Turn of the 21st Century in Hannover, Germany (2000); the Johannesburg Call in Johannesburg, South Africa (2002); and the Inspiring Futures—Aalborg+10 Conference in Aalborg, Denmark (2004) [75]. The Campaign for Sustainable Cities and Communities was initiated at the conclusion of the First European Conference on Sustainable Development, which was held in Aalborg in 1994. Initially, 80 local European representatives signed the manifesto and pledged to adhere to its guidelines. To date, the Aalborg Charter has received signatories from more than 2000 local and regional levels (metropolitan areas, cities, towns, counties, etc.) spread across 42 countries. The Second European Conference for the Sustainable Development of Cities and Towns (Lisbon, October 1996) [75], which attracted more than 1000 participants, gave impetus to further campaigns. This emerged in the Lisbon Action Plan, which further translates the principles of the Aalborg Charter into concrete action. It is evident that both the Aalborg Charter and the Lisbon Action Plan provide a framework with which local and regional authorities can support their sustainable development [61,62].

In 1998/99, a series of four regional conferences were held on specific issues for all parts of Europe. The primary objective of these conferences was to promote the “Local Agenda 21” and the concept of sustainable development throughout Europe. The following institutions were hosts to the events in question, listed in sequential order. The following locations were visited for the purpose of the study: Turku, Finland (3–6 September 1998); Sofia, Bulgaria (12–15 November 1998); Sevilla, Spain (21–23 January 1999); and The Hague, the Netherlands (23–25 June 1999). The culmination of these conferences was the formulation of a special declaration by the regional conference [76]. The third “Pan-European Conference on Sustainable Cities and Communities” was held in Hanover, Germany, from 9 to 12 February 2000. It is evident that throughout the course of the aforementioned conference, a total of 62 European local and regional authorities appended their signatures to the Aalborg Charter [61].

For a considerable duration, the European Union refrained from formulating urban policies, as it lacked the formal authority to do so, in accordance with the provisions of the Treaties. However, it is important to acknowledge that the role of cities in relation to cohesion policy and regional development policies cannot be disregarded. Consequently, normative models for cities have been increasingly defined by political bodies. This process began in May 1999 in Potsdam by the ministers responsible for spatial planning matters, who presented the European Spatial Development Perspective: Towards Balanced and Sustainable Development of the Territory of the European Union. The document demonstrates an acknowledgement of the necessity to conceptualize the sustainable development of cities [74].

The New Leipzig Charter—“Green City” (2021) is one of the pillars of the European Union’s new urban policy, representing a continuation and development of the original 2007 Leipzig Charter on Sustainable European Cities. The history of the EU Urban Agenda is intrinsically linked to the aspiration of EU Member States to encourage sustainable, equitable, and resilient urban development [67]. It is also worth mentioning the activities and documents of the European Union that are part of the acquis relating to contemporary urban development [77]. It is also pertinent to mention the work of the United Nations (UN) for sustainable urban development around the world. Within the UN, there is a specialized program dealing with issues of urbanization and human settlements, including the promotion of sustainable urban centers. This program is known as the United Nations Human Settlements Program (UN-Habitat). UN-Habitat is responsible for the organization of global debates and conferences on the challenges of sustainable urban development.

The United Nations has issued a call for a paradigm shift in the methodologies employed in the domains of urban planning, design, financing, and governance. This call has been articulated within the United Nations New Urban Agenda document, which was adopted at the most recent Habitat conference in 2016. The document presents a global vision, goals, and priorities for sustainable urban development over the next 20 years. It is instrumental in implementing the objectives of the UN Agenda 2030, with a particular focus on Goal 11, which emphasizes the creation of sustainable cities and communities. The primary objective is to establish equitable, secure, sustainable, and resilient urban centers that provide a superior quality of life for all residents. This is to be achieved whilst ensuring social inclusion and environmental sustainability [73].

The recently adopted UN Urban Agenda underscores the imperative for collaboration among all levels of government to facilitate the realization of sustainable, integrated urban development. The document delineates a series of demands pertaining to the social, economic, and environmental dimensions, which UN members have committed to implementing in their respective countries. One of the tools employed by UN-Habitat to facilitate a global discussion on the direction of urban development is the biennial World Urban Forum. This event enables systematic tracking of current trends and challenges, and their integration into local development contexts [78].

The Davos Declaration: The document Towards a High-Quality Baukultur for Europe was formally adopted on 22 January 2018 at the Conference of European Ministers of Culture in Davos, Switzerland. The objective of this initiative is to advocate for a holistic approach to spatial design, encompassing both cultural heritage and contemporary construction. This approach is founded on a comprehensive set of values, including social, aesthetic, environmental, and functional considerations [79].

The OECD has dedicated a considerable amount of time and resources to the subject of urban development. This commitment is evident in the work of two key bodies: the Committee on Regional Development Policies and the Working Group on Urban Policies. These two entities have been instrumental in establishing the OECD’s own databases, conducting a series of metropolitan and urban reviews, conducting thematic analyses, and fostering the exchange of experiences among members. Following a period of research and development that spanned more than two decades, the OECD Principles for Urban Policies were established in 2019. The overarching aim of these principles is to provide support to member states and cities in the development of coherent, integrated, and effective urban policies [80].

During the EU’s 2014–2020 financial period, cohesion policy was utilized to implement integrated strategies addressing social, economic, and environmental challenges. The European Regional Development Fund (ERDF) stipulated that a minimum of 5% of its resources be allocated to the promotion of sustainable urban development [77]. Integrated Territorial Investments were initiated to promote coordinated urban actions, and Urban Innovative Actions (UIA) were launched to fund innovative urban projects. Furthermore, the URBACT program persisted in its efforts to encourage the exchange of knowledge and the dissemination of best practices among urban centers.

In the 2021–2027 period, sustainable urban development remains a priority within EU cohesion policy, with at least 8% of the European Regional Development Fund (ERDF) allocated nationally for this purpose. Territorial instruments such as integrated territorial investments and community-led local development will continue to be utilized. The 4th edition of the URBACT program will facilitate ongoing cooperation between cities. Moreover, the European Commission is launching the European Urban Initiative (EUI) to strengthen integrated urban development and better connect it to EU policies, particularly cohesion policy. The European Commission has asserted that cities must play an active role in the design and implementation of European policies [81].

2.2. Current Cities’ Problems

It is not feasible to provide a comprehensive description of all the documents listed above; this is not the objective of this study. It is assumed that the various problems that are likely to be encountered by residents will be addressed and that the issues most strongly articulated in urban manifestos will be presented. Despite being published many years ago, some of these texts are still relevant today, as a well-functioning city remains the ideal to which we aspire.

The cities’ problems can be divided into several thematic sections, which collectively present the most pressing issues currently facing cities. The city is primarily constituted by human beings—residents and those who benefit from the advantages of agglomeration. This underscores the significance of demographic considerations in the pursuit of optimal urban form. The issue of overpopulation was already addressed in one of the earliest documents seeking to determine the optimal design for a modern city—the Athens Charter (1933) [58]. The consequence of this state of affairs is, amongst other factors, substandard housing conditions. The Machu Picchu Charter, a document that follows on from the recommendations of the Athens Charter, also draws attention to the increasing number of people living in cities [59]. This is a direct cause of the ecological, energy, and food crises. In a similar manner, the core emphasis of the 1998 Athens Charter is oriented toward the requirements of residents and users of cities in a rapidly evolving global context [64]. The European Spatial Planning Charter (2012) also emphasizes that one of the primary challenges confronting urban areas is the management of demographic shifts [62]. The shifting demographic landscape of Europe’s ageing society is characterized by a transformation in the balance between different age groups, which is giving rise to novel and expanding social challenges. This issue is also addressed in the Leipzig Charter [67] and the Toledo Declaration [69].

Another frequently raised issue is the social problems of cities. The Athens Charter of 1933 emphasized that cities had ceased to fulfil their basic function, namely to satisfy the psychological needs of their inhabitants [58]. The New Athens Charter of 2003 [65], the European Spatial Planning Charter (2012) [62], the Leipzig Charter [67], and the Toledo Declaration [69] emphasize that discrepancies in the standard of living of agglomeration residents and social inequalities are becoming increasingly visible, deepened by unregulated markets and the process of globalization [75]. The challenges posed by unemployment, poverty, social exclusion, homelessness, crime, and violence are increasingly impacting urban residents, thereby diminishing their quality of life. Conversely, the Charter of the New Urbanism [60] draws attention to the growing anonymity of urban communities and economic and social segregation in cities. In the Sofia Declaration [63], the issues of poverty and unemployment are addressed, in addition to the issue of unequal access to resources and power during the transition phase, which has resulted in the exacerbation of social disparities. The consequences of this situation are felt most acutely by women, young people, the elderly, and minority groups. The Toledo Declaration also identifies weak cohesion and increasing social polarization as threats to urban areas, exacerbated by significant economic disparities within individual cities [69].

The analyzed documents present a historical and thematic overview of key urban planning charters and declarations addressing the challenges of modern urbanization. The genesis of this discourse can be traced back to the 1933 Athens Charter [58], which first identified a paucity of green space, recreational areas, and functional zoning. Subsequent documents, including the Machu Picchu Charter, the New Athens Charters (1998, 2003), the Charter of the New Urbanism, the European Spatial Planning Charter (2012), the Sofia Declaration, and the Toledo Declaration, have successively expanded upon these concerns. The core issues emphasized across these documents are as follows:

• The paucity of accessible, open green spaces is a matter of concern;
• The issue of urban fragmentation and lack of cohesion in urban form is of particular concern;
• The phenomenon of socio-spatial segregation is characterized by the presence of distinct areas that are distinguished by significant disparities in socio-economic status, often referred to as ‘enclaves of wealth and poverty’;
• The expansion of urban areas into surrounding rural regions, often referred to as ‘urban sprawl’, and the unregulated development of suburbs, known as ‘unregulated suburbanization’, are significant issues in contemporary urban planning and environmental studies;
• The decline of historic centers and the loss of architectural identity are phenomena that have been observed in recent years;
• The environmental and social implications of uncontrolled land consumption and infrastructural dispersion are of significant concern.

Suburbanization, a prominent trend, is observed to vary in both scale and timing on a global scale. It emerges earlier in Western contexts and more recently in Central and Eastern Europe. This process has implications for both residential patterns and the spatial distribution of economic activity. Collectively, these charters advocate for integrated, compact, and cohesive urban development that supports high living standards, sustainable land use, and the preservation of both cultural heritage and natural environments.

A significant proportion of the manifestos under scrutiny is dedicated to the environmental challenges faced by urban areas. The Machu Picchu Charter asserts that environmental degradation is a consequence of rapid and unplanned urbanization and the exploitation of natural resources. In densely populated areas, the issue is primarily characterized by inadequate sanitary conditions, substantial water and food contamination, and the violation of noise standards. A further problematic issue pertaining to urban activities is the diminishing availability of natural resources and the escalating costs of energy [59]. The New Athens Charter of 2003 underscores the gravity of environmental degradation, emphasizing its status as a pressing concern. It acknowledges the decline in biodiversity and the escalating threat of extreme phenomena, such as floods, which underscore the necessity for urgent action. There is a necessity to integrate the natural environment with the urban environment and to promote the sustainable use of resources. Furthermore, the location of investments that fail to consider the natural environment is evident [65]. A significant component of the European Spatial Planning Charter (2012) pertains to environmental concerns, including the escalating issue of pollution and environmental degradation [62]. Conversely, the New Urbanism Charter highlights the correlation between the deterioration of the natural environment in urban areas and the resultant unfriendliness of the living environment, as well as the high energy consumption of cities, which renders them unecological [60].

The Sofia Declaration primarily concerns environmental aspects, with particular reference to insufficient natural resources, poor housing and working conditions, air pollution, excessive noise, degradation of the landscape and environment, and poor water management. The conference in Sofia constituted the second of four regional conferences for the eco-development of cities and municipalities. The fundamental premise of the concept under discussion was to “serve the idea of sustainable development”, with the understanding that both the economic and human development policies must guarantee health and a high quality of life within the exploitation potential of existing ecosystems. Concerns pertaining to the worldwide deterioration of the natural environment, which exacerbates economic challenges and societal disparities, possess both global and local dimensions. The assertion that sustainable development represents the sole path of progress that will ensure the avoidance of conflicts and the establishment of peace is a key tenet of the Sofia Declaration [63].

Another initiative for sustainable development was the Inspiring Futures Conference—Aalborg+10 [66]. At this event, 650 local and regional authorities from 32 European countries signed the “Charter of European Cities and Municipalities for Sustainable Development—Aalborg Charter”. The signatories made a promise to act for sustainable development at the local level by committing to “engage in the activities of Local Agenda 21 and to join the European Campaign for Sustainable Cities and Municipalities”. The Aalborg Charter comprises three primary sections. The initial segment constitutes a proclamation by European cities and towns in favor of sustainable development. This constitutes a political framework that enables local authorities to instigate the processes of formulating sustainable development plans at the local level. In Part II of the Aalborg Charter, the signatories initiated the Campaign for Sustainable Cities, with the objective of encouraging and supporting cities and municipalities in their efforts toward sustainable development. The Aalborg+10 Declaration emphasizes the need to reduce the carbon footprint of cities and promote sustainable transport, energy efficiency, and green infrastructure. As outlined in Part II of the Aalborg Charter, the fundamental activities of the campaign are delineated, with an emphasis on the encouragement of all local authorities, cities, and towns to participate by adopting and signing the Charter. As stated in Part III of the Aalborg Charter, those participating in the Campaign are encouraged to lead Local Agenda 21 processes. Furthermore, the Charter presents the process of developing a local action plan [55,61,66]. This subject is intimately associated with the global struggle against climate change, and it constitutes a pivotal component of urban policy and spatial planning. Nowadays, the issue of reducing greenhouse gases has been identified as a key concern in numerous documents addressing urban issues on a global scale.

The document under consideration commences with the assertion that metropolitan areas are incapable of accommodating an escalation in ecological challenges and environmental degradation. Conference members provided support for the implementation of local strategy and European policies, including the Lisbon Strategy, the European Sustainable Development Strategy, the Sixth Environmental Action Program, the Urban Environment Strategy, as well as the European initiative on climate change, on governance, on the implementation of the UN Millennium Development Goals and the Johannesburg Implementation Plan. In a similar vein, the Leipzig Charter on “Sustainable European Cities” (2007), created as a document of the Member States of the European Union, was established [77].

Urban infrastructure is a relatively under-researched area in urban studies, and as such, it does not occupy much space in urban manifestos. The most frequently reported issues pertain to transportation. The Machu Picchu Charter [59] and the New Charter of Athens 2003 [64] emphasize that the poor quality and efficiency of infrastructure are the result of the financial and social problems of cities. The issue of transport has become increasingly problematic, with many commentators attributing this to the rise of suburbanization, which has resulted in longer commutes and, by extension, a deterioration in services and facilities. The European Spatial Planning Charter (2012) asserts that the development of new transport infrastructure and network infrastructure is frequently characterized by a disorderly and haphazard approach, with the primary objective of providing connectivity between the dispersed activities of urban areas and their chaotically developed components. This approach often results in the excessive division and destruction of land, a major natural resource that is not renewable [70].

It is evident that economic and commercial issues were addressed in a limited number of manifestos. As stated in the Athens Charter of 1933, industrialization was presented as both a driving force of city development and a force with the potential to destroy the urban fabric [58]. This phenomenon is especially evident in European cities, which were distinguished by widespread industrialization that impacted numerous aspects of urban life [31]. In urban areas of that period, a marked predominance of economic interests over social interests was also evident. The aforementioned issues continue to represent a significant challenge for numerous urban areas. The Machu Picchu Charter regards economic growth as a force that is inimical to the quality of life. This phenomenon occurs when urban planning becomes a priority, with the needs of the city’s inhabitants being overlooked [59]. A significant challenge faced by numerous cities is the scarcity of housing, a matter that has been addressed in the Leipzig Charter [67]. The 2003 Athens Charter places particular emphasis on the manner in which globalization serves to augment the impact of external factors on the development of urban areas, thereby diminishing the capacity of domestic resources and regional networks to exert influence [65].

As stated in the European Spatial Planning Charter 2012, the challenges faced by cities include globalization and the decline of traditional industries [70]. Conversely, the Charter of New Urbanism places emphasis on underinvestment in city centers [60]. During an informal meeting of EU ministers on Urban Development, the main topic of which was “integrated urban regeneration”, the Toledo Declaration (2010) was created. The objective of the present study was to reflect on the challenges that the current globalizing world poses to cities and to achieve more sustainable development, as well as to indicate guidelines for integrated urban regeneration [69]. This decision was consistent with the precedent set by the rulings in Leipzig and Marseille. The aforementioned declaration highlighted a number of issues, with the necessity for revitalization being a key concern. In addition to this, the financial and economic recession experienced by the cities was identified as a significant challenge.

The subjects of urban management and social participation have also become the focus of those creating urban manifestos and declarations. The Machu Picchu Charter underscores the fact that, despite numerous appeals and publicity, the problems or needs of cities listed in this chapter are frequently not given due consideration in regional and national plans. It is evident that, at the level of planning and decision-making, they are rendered ineffective, thereby causing a marked disconnection between the desired and actual state of well-functioning cities. This process is further hindered by the exclusion of local residents from active participation, thereby impeding their capacity to influence decisions that impact their immediate environment [59]. The New Charter of Athens (1998) also emphasizes the dearth of effective and well-functioning social participation, a problem that remains pervasive in numerous cities. The primary concern is the inactivity of various social groups and the absence of interaction between them [64]. This issue is associated with the necessity to establish a novel system of governance that incorporates social participation, as emphasized in the New Athens Charter 2003 [65].

The European Charter on Spatial Planning (2012) highlights urban governance systems that are frequently constrained by the perspectives and voices of permanent residents and influential economic interests, favoring lobbyists [70]. The Toledo Declaration underscores the waning public interest in the planning process, as evidenced by the underrepresentation of public participation and the prevalence of uncontrolled, chaotic urban governance [69].

The manifestos analyzed demonstrate an absence of consideration for the cultural issues that are prevalent in urban areas. The Machu Picchu Charter underscores the pivotal issue confronting urban centers, namely, the pernicious impact of spatial constraints on the preservation of cultural and historical values. These values, often deemed “less lucrative” in the context of urban planning, are continually under threat due to the persistent scarcity of space allocated for “more lucrative” functions within urban areas. This phenomenon is a contributing factor to the deterioration of the standard and quality of life of the inhabitants of agglomerations [59]. The cultural diversity that characterizes European cities is a key factor in their unique identity and distinction from other regions. As stated in the New Athens Charter of 2003, since the advent of the 21st century, cities have become increasingly indistinguishable, resulting in a threat to their cultural identities and individualities [65]. The European Spatial Planning Charter (2012) highlights the increasing cultural homogenization, the emergence of novel development pressures, and the erosion of local identity in urban areas [70]. The New Urbanism Charter highlights the issue of urban heritage at risk. The preservation of buildings with significant social and cultural value is a complex challenge in urban development, particularly in densely populated cities [60].

2.3. Development Visions

The development visions presented in manifestos, charters, or declarations constitute a response to the problematic state of urban environments, which are characterized by their failure to function effectively and fulfill their fundamental roles, including the provision of physical and mental needs for their inhabitants. The following section will present a selection of documents and their search for a suitable form of the city.

The objective of the Athens Charter (1933) was to ascertain an answer to a question that had become a source of concern for numerous specialists in the field of urban planning: namely, what form should a modern city take? The period during which the Charter was in force extended from the mid-1930s to the 1970s. The document enumerated the primary functions that it deemed essential for any given city to fulfil, categorized as follows: housing, employment, communication, and leisure. As posited in the Charter, the concept of functional zoning in urban planning constitutes a primary tenet. The Athenian Charter of 1933 advocated for the separation of residential, occupational, and recreational functions by green belts, with the integration of these functions facilitated by communication axes. The human being and his needs were averaged across the four sub-points mentioned. Society was treated as a machine. It is evident that the Athens Charter adopts a rather radical attitude toward historical buildings. The primary values prioritized by the creators (including Le Corbusier) are sun, space, and greenery. The initial objective was to accomplish this by creating larger spaces between buildings and eliminating courtyards, which were characterized by their limited illumination and served as a distinctive feature of traditional tenement housing. The solution to the issue of overpopulation was to implement a strategy of high-density development, which entailed the construction of taller buildings. The concept of increased spatial capacity entailed the development of larger residential apartments and the creation of unfenced areas within housing estates. The demolition of obsolete structures is imperative for the creation of recreational areas, necessitating the construction of new buildings. The paucity of greenery was addressed through a top-down approach, with the design of green spaces from above, encompassing planned parks, squares, and gardens on roofs [58].

The following zoning was proposed for urban areas: the urban landscape is to be organized into distinct zones, each with its own function; the city center is to serve as the primary administrative, commercial, and cultural hub, while the peripheral zone is to be dedicated to industrial and residential activities; a belt is to be established around the city center, separating industry and commerce from residential areas; and the periphery is to be reserved exclusively for residential development, inscribed within the green belt [58].

In the process of urban design, economic and political factors predominate, while social considerations are often marginal. The aforementioned assumptions were directed more toward the collective than the individual. It is widely accepted that the Athens Charter engenders a sense of spatial loss, primarily due to its fragmentation of the blocks and the subsequent loss of the courtyard. Nevertheless, it is an irrefutable fact that “the most fundamental tenets of the Charter remain constant and continue to hold relevance” [58]:

• In terms of urban planning, residential districts should be situated in areas of the city that are conducive to human habitation;
• These areas should be selected based on factors such as topography, climate, and the presence of green spaces and sunlight;
• The layout of residential districts in the city plan should be informed by health conditions in a given urban zone;
• Each residential district should have a green area of a suitable size, arranged in a rational manner;
• This green space should be intended for various purposes, including play and sports for children and adults, children’s gardens, areas of kindergartens, schools, and other public buildings.

The distance between residential and working areas should be minimized. Industrial districts should be separated from residential districts by ‘neutral zones’ (i.e., areas designated for greenery and sports). Small, integral establishments (i.e., those providing crafts, supplies, and repair services) should be located in residential districts and serve the local population. Residential districts should be isolated by greenery from major communication arteries [58].

The 1977 Machu Picchu Charter posited the notion that urban planning should not be divorced from its environmental context, emphasizing the importance of considering functional relationships in urban design. It was imperative to interpret and respond to the needs of residents, especially through the provision of urban services, the creation of facilities and forms appropriate to the needs of residents, and the care of cultural resources and values. It is imperative that there is systematic and continuous interaction and cooperation between design professions, city residents and communities, and political leadership. The city should be regarded as a multifunctional organism, lacking internal divisions, the basis of which is interaction and communication between residents. Achieving a high level of quality of life is just as important as achieving balance in the natural environment. Another salient issue is that of societal participation in creative social participation, which is manifested in various forms, including the participation of users in the design and construction of new facilities. It is imperative that housing is responsive to the evolving requirements of diverse social, age, and economic demographics. Consequently, cities should endeavor to provide affordable housing for less affluent social groups, thereby counteracting social exclusion to the greatest extent possible [59].

In order to ensure the effective functioning of public transport systems, it is imperative that they be meticulously planned with two key considerations in mind: the needs of urbanization and the decreasing availability of energy resources. Conversely, planners must conceptualize the city as a perpetually evolving entity, particularly in regard to its transport infrastructure. Their deliberations ought to be informed by a forward-thinking perspective, ensuring that decisions made today do not impede future development prospects but rather foster them. Furthermore, the planning process must consider the necessity of maintaining optimal accessibility to urban areas, or at the very least, identifying the most efficacious solution for the limited accessibility of such areas. It is imperative to acknowledge the significance of environmental concerns, as they pertain to the natural world and its preservation. The Charter demands the most expeditious actions by municipal services and urban planners to curtail further environmental contamination and the degradation of ecological standards in urban areas. Furthermore, it is imperative that all cultural and historical values in urban areas are safeguarded. The revitalization and renovation of historical areas must take into account contemporary construction of high architectural quality, and new technologies, thanks to their skillful use, should contribute to the development of cities, and not to their degradation. The remit of planners should not be confined to the creation of local spatial development plans but should also encompass their implementation and monitoring to ensure that recommendations are being put into practice. It is imperative that actions for each city and region are individualized by creating appropriate standards and development bases. This process must take into account the natural environment and available resources. Such measures are intended to prevent the adoption of unsuitable solutions from other cities, which are subject to different natural and cultural conditions, from being implemented. The failure of such solutions can result in the introduction of urban and spatial chaos over time [59].

The New Athens Charter (1998) was a response to the development of open urban spaces, principally city parks and green areas of housing estates, which resulted from the efforts to create a compact city (laissez-faire in spatial planning). The fundamental assumptions of this document pertained to the principles of designing “the entire historic centre as a single organism subject to protection and comprehensive restoration” (the same rigorously observed conservation methods should be maintained in relation to ordinary buildings as in the case of historic buildings). The general principles of 21st-century urban planning have been described [64].

It is imperative that city centers are equipped with public spaces that are universally accessible and serve a function that is not subject to restricted use. The revitalization of the center must be comprehensive, as an organism linked synergistically. The value of space in urbanized areas is a value in itself (it is subject to protection because it is endangered). The value of open areas (greenery) is the highest value and should be protected above all. The protection of urban development assumptions that give cities an individual character (authorial urban solutions) is also vital [64].

The Charter is predicated on the introduction of novel management systems and methodologies for engaging citizens in decision-making processes, leveraging the advantages offered by contemporary forms of communication and information technologies. Concurrently, the Charter has the capacity to exert a substantial influence on the evolution of urban areas, where planning assumes a pivotal role, as well as in regions where its impact is comparatively negligible [64].

The vision set out in the New Athens Charter of 2003 placed emphasis on the enhancement of the most valuable features of cities, including cultural wealth and diversity. Urban settlements ought to organize themselves in networks and base their activities on competitiveness, innovation, and the use of the creative aspect that accompanies such centers. It is imperative that these units are capable of integrating the urban environment with the natural one, and that their multifunctional activities contribute to the well-being and comfortable life of their inhabitants [68].

The conceptualization of the future of cities is predicated on the notion of the “coherent city”, a concept which encompasses multi-level integration in the spatial, social, economic, and environmental domains. Temporal coherence can be defined as the continuation of historical continuity and the preservation of the city’s identity. A significant long-term objective is the conservation of urban diversity, a factor that exerts a considerable influence on the level of “urban culture”. The concept of social cohesion is intricately linked to that of social balance, respect for human rights, and the diversity of the communities that constitute society. The New Athens Charter of 2003 underscores the significance of public involvement through systems of representation and participation, access to information, and active citizenship in shaping the future of their urban environment [68].

Social cohesion can be defined as the balance and adaptation between different cultural groups, as well as a sense of identity and intergenerational relations. The phenomenon of economic cohesion is intrinsically linked to the processes of globalization and regionalization, whereby local and regional economies are increasingly dependent on external localities and regions. In order to maintain a competitive advantage, cities must engage in continuous learning and adaptation to changes in service provision. Furthermore, it is imperative for cities to establish network connections in order to enhance their competitiveness. The concept of diversity in economic development encompasses the presence of economic links that serve to promote diversity [68].

The notion of environmental coherence is associated with ecological balance, nature conservation, and sustainable utilization of resources. The field of urban design occupies a pivotal role in the realm of urban renewal, with the overarching objective of cultivating healthy cities that seamlessly integrate nature, landscape, and accessible open spaces. In accordance with this concept, it is imperative to reinforce the network of functional spatial relationships both within and in the immediate vicinity of urban areas. It is imperative to ensure the coherent character and historical continuity of cities, as well as to improve the quality of life. Urban design is an activity that has the potential to contribute to the process of urban renewal [68].

A further task for the future is the coherence of actions of urban planners and spatial planning specialists, in order to create a network of connections between cities. Furthermore, it is imperative to ensure a high level of social peace and comfort of life, as well as work, conducting business, and access to service facilities. The vision of cities of the future articulated by the creators of the New Athens Charter 2003 encompasses the issue of social participation. An increasing number of cities, particularly those experiencing rapid development, are evolving beyond their traditional role as mere residential areas for their inhabitants. These centers are characterized by their dynamism, attracting a considerable number of interested parties and users on a daily basis. It is imperative to recognize the right of these individuals to participate in the decision-making process concerning the city. The vision of future coherent cities presents their multiculturalism as an asset. The preservation of cultural identity among residents should be pursued in conjunction with the promotion of traditional practices among other groups [68].

The European Spatial Planning Charter (2012) comprises three sections. The initial section of this text outlines a proposed future vision for European cities and regions, with the aim of providing a response to the challenges currently being faced by Europe. This paper sets out a vision for a network of cities and regions-territories that will contribute to the well-being and quality of life of their inhabitants and other stakeholders. The cultural richness and diversity inherited from a long history will be preserved. The network will link more closely with each other through a wide range of functional, social, and cultural links. Competition between the regions will be encouraged, while at the same time striving for complementarity and cooperation. The human environment will be integrated with natural ecosystems, while biodiversity will be preserved, and the need to combat activities that affect climate change will be taken into account. In Part B of the European Planning Charter, the role of spatial planning and planners in providing a vision in light of the major global challenges that Europe now faces is set out. The third part of the European Planning Charter details the tasks (obligations) of spatial planners in Europe with regard to the vision set out in Part A [70].

The European Planning Charter is predicated on the promotion of the vision of the Integrated Cities and Regions Territory that is well-connected to all who live, work, and visit it and that is globally connected. Integration will be achieved through a complex of urban networks, many of which extend beyond national boundaries within the European continent. An Integrated City and Region Territory requires sensitivity to the relationship with the built and natural environment, as well as effective and efficient connections between urban functions, infrastructure networks, and information and communication technologies [70].

A fundamental aspect of future urban development is the necessity of harmonious collaboration between urban planners and specialists in the field of urban planning, with the objective of establishing a network of interconnected cities. Furthermore, it is imperative to ensure a high level of social peace and comfort in living, working, conducting business, and accessing services. The New Charter of Athens, developed in 2003, emphasizes the need for public participation in the shaping of cities. Urban areas, particularly those undergoing rapid development, are no longer confined to their original function as residential spaces. Instead, they are evolving into dynamic environments that attract a diverse range of stakeholders and users. It is therefore important to take into account the right of these people to participate in the decision-making process concerning the city. The vision of future cohesive cities also assumes multiculturalism as an asset. It is imperative to safeguard the cultural identity of the indigenous populace, whilst concurrently promoting the traditions of other social groups [68].

The Charter also refers to policies, actions, and interventions in which the urban planner should play a key role. The following points are to be considered in order to achieve the objective of revitalization of urban design for the purpose of protecting and enhancing the public sphere:

• Rehabilitation of degraded or poorly planned places and buildings;
• Measures to facilitate meeting places and opportunities for social coexistence and access to cultural, leisure, and recreational facilities;
• Measures to ensure an individual and collective sense of security;
• Creation of significant places and landscapes;
• Protection and management of all significant elements of natural and cultural heritage [68].

Introduced in 1993, New Urbanism aims to revitalize existing urban centers and create cohesive metropolitan regions. Transforming suburban areas into diverse and connected neighborhood communities is key, as is preserving the natural environment and cultural heritage. The principles of New Urbanism include the importance of diverse neighborhoods with a mix of functions and residents, designing communities with pedestrians, public transport, and cars in mind, and prioritizing public spaces and community facilities that are accessible to all. Architectural and landscape design should reflect local history, climate, ecology, and building traditions. Citizen participation in the planning and design process is also emphasized, as are social policies and development practices based on the 27 principles outlined in the New Urbanism Charter. Metropolitan areas are seen as the primary unit for planning and development, with an emphasis on internal development and a balance of residential and work functions. Overall, New Urbanism seeks to create sustainable and inclusive cities that respect the historic fabric and prioritize the needs of all residents [60].

The Sofia Declaration of 1998 emphasizes the need for cities to create conditions that support a stable economy, job creation, and social equity, while protecting the natural environment. To achieve this, various governance instruments should be used to motivate and incentivize investors toward eco-development. The declaration highlights the importance of sustainable infrastructure and public services, such as waste management, district heating networks, and wastewater treatment plants, to benefit both current and future generations. The vision for future cities also includes urban planning, sustainable transport systems, and cooperation between cities. Land and agricultural reform is also crucial to moving away from industrialized agriculture, promoting local food supplies, and preventing urban sprawl. The Declaration also highlights the need for effective shared management of international water resources and the development of democratic societies with citizen participation in decision-making processes. Integrity and transparency in politics are also emphasized [63].

The Inspiring Futures—Aalborg+10 conference in 2004 outlined a vision for sustainable and ecologically developed cities. The focus was on creating jobs in the knowledge economy, combating poverty and social exclusion, ensuring environmental protection, reducing the ecological footprint, responding to demographic change, promoting cultural diversity, and preventing social conflict. The commitments made in the Aalborg Charter+10 aimed to build on earlier declarations on sustainable development. Ten sections highlighted areas for attention, such as increasing public participation in decision-making; implementing effective governance cycles; protecting natural resources and ensuring equitable access; promoting sustainable consumption and production; addressing environmental and social issues through strategic urban planning; recognizing the interdependence of transport, health, and the environment; promoting the health and well-being of citizens; supporting local economies without damaging the environment; promoting inclusiveness and community support; and assuming global responsibility for peace, justice, equity, sustainable development, and climate protection. Overall, the focus was on creating cities that are environmentally friendly, socially inclusive, and economically sustainable [66].

Leipzig’s vision for cities of the future revolves around two key themes: integrated urban development and neighborhoods in crisis. To increase the competitiveness of European cities, the recommendations emphasize the creation of high-quality public spaces, urban cultural landscapes, and the development of architecture and urban infrastructure. The aim is to improve the living conditions of city dwellers. Infrastructure networks should be modernized and energy efficiency improved to improve the quality of life and environmental sustainability. The concept of mixing housing, jobs, education, and leisure activities within neighborhoods is promoted to reduce commuting distances. The Charter also emphasizes the importance of active innovation and education policies, as well as the promotion of social and intercultural dialogue. In the context of neighborhoods in crisis, the focus is on creating prospects, supporting affected citizens, and offering preventive measures. This includes improving the physical conditions and energy efficiency of housing, strengthening local economic and labor market policies, and providing access to quality education and training. Efficient and affordable public transport should also be promoted to ensure mobility for citizens in crisis areas [72].

The Toledo Declaration promotes an integrated and sustainable approach to urban development in the context of the implementation of the objectives of the Europe 2020 Strategy, emphasizing social inclusion, territorial cohesion, and the involvement of local authorities. It stresses the importance of integrated urban regeneration strategies and the need to continue European initiatives such as the Marseille process and the development of the European Urban Agenda [69].

The document points to the need for better coordination between sectoral policies and levels of government (multi-level governance), and for exploiting Europe’s territorial potential and geographical diversity. It encourages the promotion of scientific research, comparative analysis, and the dissemination of knowledge on urban issues. The declaration also includes a reference document on integrated urban regeneration as a tool for implementing three key priorities of the Europe 2020 strategy:

• Smart growth—based on knowledge and innovation;
• Sustainable growth—based on resource efficiency and competitiveness;
• Inclusive growth—promoting employment and social and territorial cohesion.

The document points out that cities are key to meeting Europe’s future challenges and that their potential should be fully exploited through comprehensive and coherent action [69].

It was asserted that regeneration can play a strategic role in the development of urban areas. This postulate has been present in the literature for a considerable period of time [82]. Maintaining the principle of eco-efficiency will ensure that such actions are conducive to the care of the natural environment, especially in connection with reducing transport needs. The promotion of multifunctionality in urban areas, in conjunction with mobility according to the principles of sustainable development and the enhancement of energy efficiency through the reuse of land, constitutes a strategy for the conservation of urban resources and the natural environment. The declaration also makes reference to social issues, primarily due to the increasing percentage of the world’s population living in urban areas. It is imperative to make every effort to reduce social problems, including social exclusion and poverty, and housing policy is of particular significance in this regard. In terms of economic issues, it is imperative to acknowledge that “cities concentrate most of Europe’s human, social, cultural and economic capital, etc., within their territories, which renders the optimization and revitalization of cities of paramount importance for the global competitiveness strategy” [69]. In turn, given the importance of spatial planning, architecture, and culture in cities as repositories of a rich and diverse European history and culture, it is essential to ensure the quality, functionality, and aesthetic appeal of urban areas and public and other open spaces. It is imperative to enhance openness, participation, responsibility, and effectiveness in the governance of cities.

The Toledo Declaration clarifies the meaning and interpretation of an integrated approach to the development and regeneration of urban areas, emphasizing that the city should be seen as a coherent whole. This approach requires resolving conflicts and contradictions between policies, avoiding short-term management, and the creation of long-term strategic scenarios. With regard to revitalization, the document states that the aim is to optimize, preserve, and enhance the existing ‘urban capital’, including social capital, cultural heritage, and the built environment. Degraded urban areas should be seen not only as a problem but also as a potential source of development—both human and physical. Unlocking this potential should contribute to the civic progress and economic growth of the whole city [69].

3. Discussion

Population growth and urban expansion lead to increased consumption of natural resources, air, water, and soil pollution and the loss of biodiversity. Sustainable development allows for the introduction of activities aimed at minimizing negative impacts on the environment, such as promoting renewable energy, recycling, energy efficiency, and the development of green infrastructure, such as parks and green areas in cities.

Sustainable city development also means taking care of the health and well-being of its residents. Investing in clean air, better public transport, access to recreational and green areas, as well as promoting physical activity and a healthy lifestyle, contributes to improving the quality of life. Cities that focus on sustainable development are more friendly and comfortable for their residents. Sustainable development promotes the use of modern, energy-efficient technologies that reduce energy consumption. This allows cities to reduce their energy bills and also reduce their dependence on fossil energy sources, which has a positive impact on local and global economies. Using renewable energy sources, such as solar or wind energy, makes the city more independent and less exposed to energy price fluctuations.

The World Cities Report 2024 is a document that evidences a degree of concern for contemporary urban areas. Cities and Climate Action is a publication by UN-Habitat [73]. The document under scrutiny herein undertakes an analysis of the impact of climate change on urban areas and the role of cities in counteracting the climate crisis. Key issues include the problem of urban areas, which are particularly vulnerable to the effects of climate change, such as floods, heat waves, storms, and droughts. Concurrently, they bear a substantial responsibility for a considerable proportion of global greenhouse gas emissions. Furthermore, the issue of the escalating threat to urban populations is addressed. Projections indicate that by the year 2040, a population of over 2 billion residing in urban areas may witness an increase in temperature of at least 0.5 °C. This phenomenon carries significant implications for public health and the integrity of urban infrastructure. It is imperative to emphasize that in order to construct and sustain climate-resilient systems, cities require an annual investment of between USD 4.5 and 5.4 trillion, whereas the current funding allocation stands at a mere USD 831 billion. A salient issue is the decline in green areas. The average percentage of green areas in urban areas worldwide has decreased from 20% in 1990 to 14% in 2020, which has a detrimental effect on the quality of life and the ability of cities to adapt [73].

The recommendations set out in the report include the adoption of an integrated approach, the strengthening of local actions, and an increase in investments. It is imperative that cities implement strategies that combine adaptation to climate change with mitigation, taking into account social, economic, and environmental aspects. The provision of support for initiatives, both local and municipal, in the development and implementation of climate policies is of paramount importance in ensuring effective adaptation. It is imperative that increased funding is allocated to the development of climate-resilient infrastructure and the promotion of green technologies and nature-based solutions. The report emphasizes that cities play a pivotal role in the global effort to combat climate change and must assume an active role in the formulation and execution of policies at all levels of governance [73].

With regard to the main objective of this article, it can be said that the problems of cities over the last almost 100 years and the solutions to them are interestingly consistent with the conclusions of the aforementioned report. Have societies been unable to cope with the challenges of urban development for decades? The question can also be asked as to when it will be possible to implement long-term rather than ad hoc measures.

Sustainable development aims to create cities that are accessible and inclusive. This means ensuring equal access to education, work, healthcare, and culture for all social groups. Sustainable cities also support the creation of spaces that support social integration, where people of different nationalities, cultures, and social statuses can coexist in harmony and mutual respect. Climate change is one of the greatest challenges of the modern world. Cities, as places of concentration of human activity, are crucial in the fight against global warming. Implementing sustainable development strategies in cities, such as reducing CO₂ emissions, efficient water management, or increasing green areas, is essential to counteract the catastrophic effects of climate change. Sustainable urban development promotes economic stability in the long term. A responsible approach to resource management and investment helps avoid crises related to the excessive use of natural resources or environmental pollution. Sustainable development also supports innovations that can stimulate economic development and create new jobs.

Theories and strategies of urban development from the Global North can offer valuable insights and frameworks but must be adapted to the specific social, economic, cultural, and environmental contexts of the Global South. Urban theories emanating from the Global North have the capacity to serve as a source of inspiration and to offer general guidance; however, it is imperative that these theories be critically adapted, rather than being applied without critical scrutiny. Moreover, these theories should be complemented by knowledge and practices that have been developed within the local context and that are sensitive to that particular environment.

It is interesting to see whether the problems of the world’s cities and the ideas for overcoming them are sufficient to prompt corrective or optimizing action. The persistence of some urban problems for almost a century suggests that they are too difficult to solve or that the authorities of these cities are reluctant to take action.

In this respect, it would be interesting to carry out further research aimed at tracing the actions taken by the city authorities in response to the problems identified.

4. Conclusions

The city, it was written decades ago, “is probably man’s greatest achievement”. A dozen years ago, Peter Hall pointed out that while the city as a socio-spatial environment is subject to deep criticism (and rightly so), cities, especially large cities, while imperfect, while creating many problems, and while raising concerns about the future, are at the same time irreplaceable environments for innovation and creativity [83]. The expectations and hopes attached to the city have been with it throughout its history. The origins of the city are linked to new needs, both in terms of the organization of social life and of agricultural or cultural activities, and in terms of the organization and provision of the space needed to meet these needs. At the same time, this human environment, which has been created over thousands of years, is subject to constant criticism, modification, and transformation, with the constant hope of achieving an ideal state, or at least something close to it [84]. This article is concerned with the presentation of urban problems, which may be defined as articulations of a novel perception of space. Urban manifestos are, by their very nature, a form of worldview, and it is through this medium that they seek to effect change in relation to previous actions. It is also important to note that manifestos are, to a certain extent, visions and wishes regarding the future development of cities. The objective of this article is to illuminate the social and spatial predicaments that characterize urban environments. At regular intervals, new analyses, appeals, or manifestos emerge within the disciplines of urban planning, architecture, and planning. These documents are designed to attract the attention of decision-makers to the widely recognized issues affecting urban areas and to propose solutions to these problems. The historical context and the order in which such documents were created have been demonstrated. The present study will commence with the inaugural initiative, the establishment in 1928 of an international organization of modernist architects, and the International Congress of Modern Architecture (CIAM) and proceed to review the numerous conferences that have transpired since. Understanding current EU regulations and UN-Habitat reports on cities is crucial today. The primary challenges confronting contemporary urban areas have been elucidated.

The urban manifestos are a response to the crisis currently being faced by contemporary cities, namely their functional, social, and environmental inefficiency. The most significant conclusions must be cited. For instance, the implementation of functional zoning and a technocratic approach to urban planning has resulted in the erosion of individual and historical heritage. Conversely, the promotion of social participation, environmental protection, and the integration of urban functions. A salient trend is the inclination towards the conservation of urban centers, public spaces, and green areas, underscoring the necessity for contemporary governance and civic participation. Another significant conclusion is the promotion of a cohesive city, which integrates social, spatial, economic, and environmental dimensions. Moreover, numerous documents underscore the imperative for sustainable development, energy system transformation, and climate protection as paramount concerns for the future of cities. Participation is also of significance. The involvement of residents in the shaping of urban space and planning decisions is of key importance. In recent years, there has been an increasing emphasis on the diversity and identity of cities. It is incumbent upon cities to protect their cultural identity and promote multiculturalism as an asset. The concept of sustainable development must not be overlooked. The necessity for a harmonious equilibrium between economic advancement and environmental preservation is emphasized. Another element is the creation and development of city networks—the future of cities lies in network cooperation based on innovation, competitiveness, and knowledge exchange. Furthermore, the revitalization of urban spaces should be focused on supporting health, safety, quality of life, and heritage. The importance of policy integration, the fight against social exclusion, energy efficiency, quality of life, and the protection of urban resources should also be emphasized. The common denominator of all these documents is the call for more sustainable, integrated, and locally adapted urban planning.

Assuming that a well-functioning city should be capable of coping with various types of problems and providing its residents with a convenient place to live [84], the issues most strongly articulated in urban manifestos have been presented. Despite being published many years ago, some of these texts remain relevant, addressing contemporary issues including demographic challenges, social, spatial, environmental, infrastructural, economic, and business problems, as well as those related to management, social participation, and cultural concerns. Subsequently, a series of development visions were presented, which are intended to address the prevailing urban challenges that are impeding the effective functioning of our cities and hindering them from fulfilling their fundamental roles, such as addressing the physical and psychological needs of their inhabitants.