(Re)Writing the City from Within: An Exploratory Approach to Sustainable Urban Morphologies from the Dialogue Between Public Space and Public Transport in Barcelona’s Trambesòs

Abstract

Research on urban transport and mobility through everyday practices has generated new theoretical and methodological approaches to achieve more sustainable urban morphologies. This paper focuses on the characterization of the process of urban (re)qualification through the binomial of public space–public transport, based on the analysis of Trambesòs tramway in Barcelona, from 2004 to the present. This methodology consisted of an exploratory morphological analysis that identified patterns derived from punctual interventions, articulation axes, and saturation pieces in the urban fabric. The results revealed three main morphological patterns: the configuration of a particular character in each public space intervention associated with the tramway, the morphological improvement and dynamization of the urban fabric, and the transformation of the city’s image through the standardization of accessibility conditions, a key social sustainability indicator. In the discussion, the results are triangulated with the concepts of urban morphology and social processes and compared with quantitative studies, which can serve as a foundation for further in-depth research. In conclusion, the tramway has facilitated a transition from urban discontinuity and segregation to continuity and cohesion, highlighting the impact of the public space–public transport binomial on more sustainable urban morphologies. This contributes to how urban morphological analysis provides new approaches to understanding public transport as an extension of public space and support for urban habitability.

1. Introduction

As an essential component of urban conditions, public transport has maintained its importance and relevance to the dynamics of a city as a whole. This is notwithstanding the fact that in the last three decades, the evolution of Information and Communication Technologies (ICTs) has significantly pointed to the systematization, interconnection, immediacy, and efficiency of the means of communication through the virtualization of various aspects of urban life [1]. This study adopts Zegras’ descriptive definition of public transport [2], which identifies infrastructure, vehicles (including pedestrians), and the physical context in which people and goods move as key components. An example is the Trambesòs tramway, where the tracks and the urban environment, comprising the urban fabric, land use, and block configuration, are linked to the urban morphology, and at the same time are an integral part of the public space, promoting social interaction and functioning as axes of connection and articulation.

In this way, this approach establishes a theoretical link between public space and transportation, which makes it possible to evaluate the performance of these systems through the variables of punctual intervention, join axes, and saturation pieces, which are explained in detail below.

Furthermore, as Oliveira pointed out [3], the integration of transport infrastructure plays a critical role in urban morphology, reinforcing the spatial and functional structure of the city. This view is also aligned with other definitions of public transport systems provided by authors such as Cervero [4], who highlighted their role as catalysts for social and spatial integration within urban areas.

This qualitative approach allowed us to understand how these infrastructures act as catalysts for the reconfiguration of public spaces and social articulation. Thus, this approach becomes necessary to support quantitative studies using tools such as Space Syntax and gravitational models.

Although transportation and communication technologies have pushed the phenomenon of metapolization of cities [5,6], they have not managed to challenge metropolitan concentration or succeed in replacing real cities with virtual ones [7,8,9]. Simultaneously, after the effects of the COVID-19 pandemic in particular, the need for physical support that allows face-to-face encounters and personal exchange (i.e., public spaces) has become one of the most sought-after (and scarce) values in urban areas.

Despite this, contemporary cities have been increasingly characterized by dispersion, disconnection, and fragmentation [10,11,12], indicating a significant dissociation or rupture between what is desired, what is thought, and what is built. Several authors have considered this dissociation as a flaw in the assimilation of the change process [13,14], further noting that a significant part of traditional public spaces has not been able to satisfy or meet the needs of today’s cities, characterized by the artificialization and denaturalization of certain urban relationships [15], leading to unsustainable processes [16]. The urban fabric, in both its physical and social dimensions, represents the different layers (relationships, buildings, routes) accumulated over time and incorporates both the territories and the groups that inhabit them. Therefore, to the extent that public spaces adapt to contemporary reality, it is possible to relativize this idea and defend the central role that public spaces and their systemic nature continue to play in the articulation and structuring of the urban fabric [17] as they still constitute physical support for the development of social and economic dynamics [18,19].

In this context, the relationship between transport and public space and its implications for mobility and accessibility has shifted from focusing on measurable and quantifiable aspects considered by urban planning to including material (physical, functional, and spatial) and immaterial aspects (perceptual, symbolic, and representational). From the intersection of these aspects in the dialogue between transportation and public space, several approaches have delved into urban morphology as a systemic support and representation of certain urban dynamics, which allows us to interpret a particular form of daily life in the city. In line with this is the work of Kevin Lynch [20,21], Pedro Brandão [22], and Aldo Rossi [23]. Studies with a greater emphasis on the systemic relationship of urban dynamics have been conducted by Gabriel Dupuy [24], who is joined by Christopher Alexander and Nikos Salingaros, who have examined the structural analysis of the city based on patterns [25,26].

In addition, mobility from everyday practices broadens the scope of the study of urban dynamics through morphology, since both have transcended from being the object of study to becoming a theoretical and methodological approach to the urban question. In line with this, it is worth mentioning the work of Latin American authors such as Guillermo Gucci and Tomás Errazuriz [27], Paola Jirón Walter Imilán [28], and Juan Montoro and Sebastián Moreno [29], among others, who delve into the problem of transportation in the city on the basis of everyday practices. These authors have delved into giving meaning to the mobile object in the material world, returning to the basis of urban experience as a representation of these practices, and to public space as a polysemic support for life in the city. This shift in approach is to be found within the social sciences in the movement known as the “mobility turn” [30,31], which has fostered an approach to the phenomena of city, society, and sustainability by studying the mobility of people, things, and ideas.

Considering the systemic point of view that sees public space as both the support of urban space as well as of social heterogeneity and its uses, the structural character of transportation and its infrastructure as something providing the backbone or vertebrante—capable of structuring and articulating the urban fabric, extending the public realm spatially, functionally, and programmatically—thus playing a central role in the contemporary city. Accordingly, the transformation value associated with public transport, specifically that of guided transport (which, owing to its immovability, allows for a prefigured urban form), is found in the possibility of hacer ciudad or making city [32].

In this context, the approach outlined in this article (re)writing the city from the inside alludes to the idea of how planning can transform the urban fabric through the modification and incorporation of infrastructure, such as guided public transport [4,33,34], incorporating the vision of Nuno Porta [35]. This emphasizes that instead of expanding fixed urban capital, we should focus on the typology and language of what has already been built, respecting the old texts that societies have written over the irreplaceable material of the ground [36]. This implies not only improving the quality of what already exists, promoting greater compactness of the urban model, but also creating new collective spaces that dialogue with the morphology of the surrounding environment. This approach to rewriting the city, in turn, presents new possibilities for addressing urban disarticulation and deterioration using a historical and morphological approach.

1.1. Transforming the City from Within

From the need to rectify the deterioration or disarticulation at different scales of the urban fabric, a logic of joint and systematic intervention arises. For example, the integration of transportation systems into the urban fabric is a key aspect of their success, as Hidalgo et al. [37] pointed out for BRT-based transport systems. This logic must cater to a sustained city project, both in the production of public spaces and in providing services and facilities. By the end of the 20th century, urban transformation processes began to interrelate fragments of the city with public transportation as the vertebrante or backbone structure, generating an articulated and cohesive urban ensemble through different urban scales. This promotes fruitful [38,39] and sustainable exchanges, and the development of “a balanced city that sustains adequate levels of urban quality throughout its municipal area, from the urban structure to the quality of urban space” [40] (p. 257).

Every urban transformation process must respond to the dynamics of a specific context, the requirements established by each type of infrastructure, and the means and modes of transportation. Based on studies [40,41,42,43], three types of intervention can be established according to the size, layout, and manner in which transportation influences or conditions a given area that complements and overlaps with each other. First, there are specific interventions designed to enhance the nearby environment and recuperate deteriorated spaces in consolidated fabrics [43] by improving the quality of the delimited space [44].

1.1.1. Punctual Interventions

Most punctual interventions are located in the middle of the consolidated fabric or on undefined borders, presenting an isolated territorial condition. That is, they do not form a network of concatenated spaces, even when some formations reach a certain degree of interrelation (network form) by articulating with each other, with other fabrics, or with consolidated systems. Their interior location indicates an “action from within the daily urban fabrics, far from the structural elements of the city such as the main road infrastructure” [40] (p. 254). Hence, the nature of these interventions aims to improve public spaces and roads by subtly modifying the already configured space so that in a larger transformation process, they are directed to meet immediate needs.

The development of punctual intervention projects progressively establishes routes and links with other similar interventions or with significant local elements (squares, markets, transport stations, and schools, among others), constituting or enhancing nodes of activity in places lacking such a programmatic situation. In this sense, the transformative power of punctual interventions is based on the possibility of their dispersion in a nearby environment [45,46]. As part of the dispersion of punctual interventions, pedestrian circuits emerge to both articulate the surrounding fabric, as well as to create new interventions in the territory.

From a transportation standpoint, the influence area of each intervention is associated with the stations of urban transport networks, such as railways, BRT, metro, or tram [47] (p. 5). Pedestrianization of these areas can cause residents to develop a sense of progressive improvement in liveability conditions through transportation. Within the framework of a larger transformation project, the reduced scale of punctual interventions allows us to perceive them as points from which the associative dynamics that will characterize subsequent intervention logics are projected and share some similarities with the Small World network diagrams initially proposed by Watts [48,49,50].

1.1.2. Articulation Axes

Second, there are interventions identified as articulation axes that respond to the complexity of a city and its various transformation requirements. These axes give continuity to the logic of punctual interventions, establishing them as articulation nodes, creating fabrics that connect various points of the city, promoting the dynamization of the transformation process, and extending its impact beyond the environment in which they are placed. Within the diverse nature of articulation axes, it is possible to distinguish two levels of action: in local streets over residential fabrics (internal network), and in a new road structure of urban character (primary and secondary networks). In this context, it is important to distinguish the change in the conception of urban roads, which goes from being conceived as rapid transit road connections and creators of segregation processes [51] to road connections linked to the urban fabric.

Because the articulation axes mainly act between already consolidated urban fabrics, they can contribute to the reorganization of a city’s general systems, achieving an immediate impact on specific areas or spaces such as free public spaces or residual areas of the consolidated fabric. Therefore, the set of interventions can act as catalysts for a broader and more complex development plan because not only do they articulate recent interventions, but they can also integrate other areas not included within the original influence area, generating links between fragments and sectors of the city through the re-compositing of the urban structure so that when combined with infrastructure (mainly the road network), they can allow for the functional and programmatic diversification of a previously empty space, forming new centralities [52,53]. In this sense, the complementarity between various projects and scales of intervention seeks the formation of articulated networks of transformed, new, or already consolidated spaces, preserving the understanding of the territory through its constituent fragments.

1.1.3. Saturation Pieces

Within this logic, larger-scale interventions arise (local, neighbourhood, city, or territorial), which merge and interrelate the previous types of logic, uniting the various interventions as part of a systemic strategy that connects the city´s different sectors with the territory through pieces of saturation [42]. These interventions act as stitches over the rupture or fragmentation of the urban fabric, generating a kind of continuity within the city´s uneven growth derived from the predominant urban models of each era. Each piece pursues the articulation and precision of the edges through a vertebrante or backbone structure, which interrelates different areas and fabrics while reorganizing each fragment from the inside.

The complexity of these interventions is due to the integration of multiple systems as part of the process of merging and restructuring, as well as by the interweaving of infrastructure, facilities, and related services. This complexity positions the saturation pieces as nodes of systemic integration [17,32], where “the nodal points where various axes converge, rather than distributing flows, can be privileged spaces for reading the urban structure, to the extent that they facilitate the understanding of the backbone role of these axes” [54] (p. 117). These nodal points are alternatives to centrality [42].

Punctual interventions, as well as articulation axes and pieces, determine the logic of multiscale action in the city. In addition to a programmatic response, it allows for new forms of urban transformation and generates a unified and continuous structure. The void becomes a compositional element that articulates systems and services and functions as an access to them. This intervention logic is significant for morphological transformation processes because every time an action is integrated with others, it modifies the initial urban condition and acts as a tool of redevelopment by modifying the qualities of public space. Hence, it allows for the revaluation of its function by focusing on the “urban composition where the different elements of urban form are combined in a coherent manner” as stated by Ünlü [55] (p.33). Symbolic and perceptive aspects are also reassessed, contributing in the same way to the consolidation of the image of the city [20,21,22,56].

1.2. The Role of Public Transport in (Re)Writing the City

As proposed, the interference of public transport in urban transformation processes is significant to the extent that it becomes a projection of the intervened public space. In this sense, public transport can form saturation pieces between territories, according to its influence area and service coverage. Thus, the idea of continuity in the imaginary is forged as a part of the consolidation process of an urban whole. This emanates from seeking to generate a set of axes that, when crossing through different urban fabrics, form an itinerary, that is, a network of public spaces, infrastructures, and systems. In the face of the latter, transportation plays a relevant role not only as a functional element but also as a referential entity and a sense of continuity between parts of the city. Therefore, transport infrastructure such as the tramway influences the perception and structuring of the urban landscape, reinforcing connectivity, accessibility, and urban cohesion, as well as consolidating a new image of the city.

Based on these ideas and in the current context in which the production of public space is conditioned by public institutions’ capabilities to manage infrastructure projects, interventions derived from public transport projects have become an important agent of change for urban space (re)generation and city structuring [46,57]. When analyzed, they can provide new management and intervention strategies. As stated by Flvbjerg et al. [58], although there may be a large investment, transportation projects do not always meet set targets or objectives. It is then necessary to start the analysis from a critical view of these objectives, which tend to overestimate possible gains.

Therefore, while it is notable that both categories of infrastructure—public space and transport infrastructure—as well as the planning and management processes of these spaces correspond to what Oliveira [59] (p. 1) defines as urban morphology, this article focuses on its urban–morphological analysis, particularly on the use of concepts such as the analysis of road networks, blocks, and plots. It can then be affirmed that this research is based on an urban–geographical approach, more linked to the German school, which prioritizes the analysis perspective from a human scale rather than using the typology approach of the Italian school.

Additionally, within the scope of urban morphology studies, it is possible to highlight the methodological analysis approaches proposed by Conzen [60] (p. 124), which emphasize how the city plan analysis reveals its physical structure and historical complexity, showing how it evolved in response to social, economic, and technological changes over time. Conzen [60] (p. 125) also states that the analysis methodology of city plans relies heavily on graphic and cartographic materials, especially large-scale detailed maps that show streets, property boundaries, and building plans.

In this context, a question arises that summarizes the research problem: How can we characterize the impact of the implementation and development of transportation and public space projects in urban transformations in terms of human-scale urban fabric experience and the consolidation of the city’s image?

Based on the above, this study aims to characterize the process of urban (re)structuring and (re)qualification based on the transformation capacity from the public space–public transport perspective. It uses as a case study the role played by the Trambesòs tramway in the urban transformation of the east area of the Besòs river in the district of Sant Martí, between Ciutadella/Vila Olímpica, the Glòries and Fòrum stations, in the city of Barcelona.

To achieve this, this article identifies as an analysis category three types of intervention logic that allow for the urban transformation mentioned previously, punctual interventions (stations and squares) and articulation axes (streets, avenues, and parks), which lead to saturation pieces (intermodal stations, metropolitan parks, etc.), thus allowing for a morphological analysis developed by layers. Next, this article proposes a methodological approach of the Trambesòs case analysis which takes into account the urban transformation processes derived from the three types of interventions previously mentioned, as an approach to the role played by the tramway in the urban transformation of the analyzed area.

With all of the above, we aim to contribute to the scholarly debate not only by providing strategies for what could constitute a morphological urban exploratory analysis, but also by providing important results relating to identifying among the different layers patterns of transformation, functional, and programmatic impact in the urban fabric since the opening of Trambesós (2004). With this methodology, we aim to lay the groundwork for further debate on the impact of transport infrastructure on public space interventions to guide future intervention strategies.

From an urban design perspective, this article contributes to how movement is understood as a continuum between public transport and public space, and to the understanding of both phenomena as active mechanisms of (re)urbanization, mainly in fragmented urban contexts with a lack of cohesion between mobility networks and public space. From an urban planning perspective, this allows us to delve into the understanding of transportation as a strategy to reserve territory for mobility and social interaction, both fundamental for the physical and social dimensions of the urban fabric, as well as a tool for the protection and enhancement of public spaces.

2. Methodology for the Analysis of Urban Transformations from Within: The Trambesòs Case

Based on the research problem defined in the previous section, the methodological design shown in Figure 1 is based on the notion of a case study [61]. It is defined by Trambesòs’ influence area and Barcelona municipality´s administrative division. This methodology aims to identify the urban–morphological patterns of transformation, as well as the functional and programmatic impact on the urban fabric, as well as the conditions of permeability, adherence to the environment, and visual and functional continuity of the image of the city resulting from the implementation of transport and public space infrastructures since the creation of Trambesòs in 2004 to the present. These patterns will allow us to characterize the impact of transport infrastructures on human-scale experiences, with emphasis on the urban fabric and the image of the city.

Two key dimensions are studied, a chronological one and a typological one. In the chronological dimension, a baseline is established, and the results are identified to facilitate the impact assessment of, in particular, a subsequent analysis of public space interventions before and after the tramway. It also consists of identifying, classifying, and synthesizing, under an internal logic, the structuring interventions of the Trambesòs’ influence area, based on a graphic mapping [62]. In the typological dimension, the aim is to obtain arguments to determine the impact of the tramway in the studied area. A comparative graphic analysis of layers is used again in which the three structuring interventions (punctual, articulation axes, and saturation pieces) are established as main categories.

The qualitative analysis in this study allows us to understand how the Trambesòs tramway acts as a catalyst to transform social dynamics and reorganize spatial relations in fragmented areas. Such qualitative aspects are crucial to understanding in an exploratory way the interference of transport infrastructure on urban cohesion and structure, elements that quantitative analysis can only complement later on. This approach, therefore, is presented as a first step to support further studies, where tools such as Space Syntax will help to evaluate accessibility and its impact on cohesion.

As a result, the analysis identified the patterns of transformation that affect the dynamics of the city and the functional and programmatic impact of each intervention (in terms of mobility, accessibility, and improvement of public spaces) on the urban fabric. Each intervention is characterized based on its spatial scale, typology, and the role it was intended to play at the time of its implementation, by the conditions of the given context, and by the technical restrictions of each infrastructure. Moreover, each intervention is critically addressed in its approach to reverse the disconnection between different fabrics (caused by various growth trends, such as the superimposition of incomplete compositional layers that generate a process of discontinuity and morphological rupture) and its capacity to generate permeability, adherence, and continuity within the morphological composition of the city.

Additionally, after analyzing the characteristics of the transformations in the study area resulting from the intervention strategies and the implementation of the tram (punctual interventions, joint axes, and saturation pieces), the analysis classified patterns based on their ability to generate less dissociated, more continuous, and diverse urban fabrics, thus demonstrating the presence or lack thereof of urban conditions such as permeability, as well as the emergence of new centralities.

Regarding the data used to produce the cartography, we resorted to the cartographic database of the Institut Cartogràfic i Geològic de Catalunya (ICGC). From there we obtained information from satellite images and files in vector format with which we created our own cartography shown in this article. Concerning the memory of interventions in the study area, several sources were used, such as the Archivo Histórico de la Ciudad Barcelona (AHCB), Arxiu Històric del Poblenou (AHPN), Arxiu Cerdà, City Council of Barcelona, and Generalitat de Catalunya, which allowed for the construction of the interventions’ timeline.

Finally, considering that the methodological design of this article adopts a qualitative approach, primarily based on graphical analysis as a comparative technique, the discussion section incorporates what Heale and Forbes [63] define as a triangulation strategy applied here in an exploratory manner. An analysis is conducted on the results of predominantly quantitative studies within the study area, prioritizing those that use spatial morphology techniques, particularly space syntax, to remain consistent with the urban morphology framework of this research. Additionally, a second comparison is introduced by employing urban indices to evaluate the accessibility and attractiveness of trips in the area, using gravitational models, which are robust indicators in urban mobility studies.

It is worth mentioning that the proposed methodology is mainly focused on the case studied; however, it is foreseen that this type of analysis and the interaction studied can be applied to other contexts of incorporation of guided transport, complemented with quantifiable data that confront the findings of this research.

3. Results

3.1. Morphological–Chronological Analysis: Identification and Classification of Structural Interventions of the Transformation

The intermediate scale organizes the city through various interventions, bringing together specific public spaces and facilities at the metropolitan level (saturation pieces) with the smaller-scale spaces that are disseminated throughout the urban fabric as punctual interventions or articulation axes (ring roads, avenues, streets, and public transport corridors), articulating both the internal morphology of the neighbourhood and the metropolitan structuring elements that provide continuity to the city, giving rise to a logic of internal transformation. Based on this logic, identifying, classifying, and assessing the scope of different interventions through time is essential to understanding their interdependence and the transformation processes that were or were not triggered by them (see Figure 2).

Towards the end of the 1980s, Barcelona’s morphological roads did not exhibit a unified and homogeneous urban continuum that addressed the disarticulation problem between adjacent urban fabrics [65] because of its historical formation and the absence of infrastructure interventions. Stemming from this condition, several interventions took as their starting point the incorporation of important facilities and directional infrastructure which were implemented in the city´s northern part and east of the Besòs river (see Figure 2), the Sant Martí district, aiming to integrate this urbanized but obsolete area disconnected from the city dynamics [66]. As shown in

Table 1. Structural interventions of the urban transformation of the area of influence of the tramway classified according to year, typology, and scale.

Intervention		Year	Type of Intervention	Scale
Interventions prior to tram incorporation	Parc de la Ciutadella (1)	1879	Punctual	City
	Parc del Clot	1986	Punctual	Local
	Parc de l’Estació del Nord (2)	1988	Punctual	City
	Rambla del Prim (11)	1989	Joint axis	Local
	Parc de Carles I	1992	Punctual	Local
	Vila Olímpica	1992	Saturation piece	City
	Av. d’Icària	1992	Joint axis	Local
	Av. del Bogatell	1992	Joint axis	Local
	Teatre Nacional de Cataluña	1996	Punctual	City
	Auditori de Barcelona	1999	Punctual	City
	Parc Diagonal Mar (10)	2002	Punctual	Local
Interventions after tram incorporation	Av. Diagonal (extension) (13)	2004	Joint axis/saturation piece	City/Local
	Jardins d’Irene Polo	2004	Punctual	Local
	Parc del Fòrum (4)	2004	Saturation piece	City
	Reforma del Borde Costero (5)	2004	Saturation piece	City
	Jardins d’ Ada Byron	2006	Punctual	Local
	Parc del Centre del Poblenou (9)	2008	Punctual	Local
	Jardins de Teresa de Calcuta	2008	Punctual	Local
	Museo del Diseño de Barcelona	2014	Punctual	City
	Parc Gran Clarina	2020	Punctual	Local
	Jardins de Ca l‘Aranyó	2020	Punctual	Local
	Av. Meridiana (6)	2004 *	Joint axis	City
	Calle de Wellington	2004 *	Joint axis	Local
	Rambla del Poblenou (8)	2004 *	Joint axis	Local
	Gran Vía de les Corts Catalanes (7)	2007 *	Joint axis	City
	Mercat de los Encants	2013 *	Punctual	Local
	Plaça de les Glòries Catalanes (3)	In progress	Saturation piece	City
	Av. Diagonal (connection)	In progress	Joint axis	City
	Distrito 22@ (12)	In progress	Saturation piece	Local

Source: own elaboration based on multiple sources. * Remodelling.

, interventions such as Parc de l’Estaciò del Nord (1988), Rambla del Prim (1989), Vila Olímpica (1992), or Parc Diagonal Mar (2002), were developed as typologically distinct interventions which lacked a dynamic and fluid integration with the city development that effectively promoted the integration east of the Besòs river area to the city.

Later on, and in addition to the incorporation of the Trambesòs, punctual interventions, such as Jardins d’Irene Polo (2004), Parc del Centre del Poblenou (2008), Museo del Diseño de Barcelona (2014), and later Jardins de Ca l’Aranyó (2020), or the remodelling of the Mercat dels Encants (2013), managed to generate new activity nodes that expanded their influence area through the flow of the Trambesòs, steadily increasing the number of passengers from 1,837,740 in 2004 to 8,337,554 passengers by 2022 [67]. Furthermore, the renovation of different articulation axes like Calle Wellington, Avinguda Meridiana, and Rambla del Poblenou in 2004, or the extension and subsequent connection of Avinguda Diagonal, all integrated into the tramway route, resulted in greater connectivity from both the city perspective and local scale. As shown in Figure 3, the continuity of the urban fabric through the extension and redevelopment of articulation axes, such as Avinguda Meridiana (6), Gran Via de les Glòries Catalanes (7), Rambla del Poble Nou (8), Rambla del Prim (11), and Avinguda Diagonal (extension) (13), enabled the correlation of said axes with punctual actions like the Parc de la Ciutadella (1), Parc del Centre del Poblenou (9), or Parc Diagonal Mar (10) with transport stations.

As a result of these punctual interventions and articulation axes, the area east of the Besòs river gave rise to saturation pieces formed by the union or agglutination of various interventions within a specific area. These pieces consolidated the urban transformation of a broad area that did not reflect nor compare to the urban reality of the rest of the city. This agglutination of various actions such as Plaça de les Glòries Catalanes (3), Parc del Fórum (4), Villa Olímpica, 22@ District (12), and Avinguda Diagonal (13) shares a double typification and scale and reflects a series of correlations with the Trambesòs route, the area itself, and the urban transformation processes. This transformation process has influenced an increase in mobility, which is reflected in the vitality of the streets, both for cyclists and pedestrians, and in the increased demand for public transportation. Of particular note is Glòries station, where metro line 1, the Trambesòs, and the bicing system converge, where the number of passengers entering the station increased by 170% between 2000 and 2015, making it one of the city’s main stations with the highest passenger demand per day [69] (p. 52).

As a consequence, and as stated by authors such as Arteaga [40], Borja [65,70], Busquets [71], and Camerin [72], the series of planned interventions sought to transform existing conditions through saturation (owing to the large number, programmatic diversity, and scale of the interventions). In the face of this, the uniqueness of each intervention was conditioned by the development of its surrounding fabric, the restructuring of the urbanized areas, and the enhancement of the city’s overall connectivity. This is directly linked to the insertion of the tramway, which allowed for the configuration of a more permeable, continuous, and balanced urban fabric. It simultaneously addressed both local- and city-level necessities and integrated existing spaces and facilities within transformation dynamics. The multidimensional characteristic of each intervention is framed on an intermediate scale, in which the tramway becomes the axis that defines a pattern of organization and structure, articulating the interventions with the rest of the city’s systems.

In synthesis, based on this analysis, it is possible to state that the transformation process for the northern area and the integration of the east of the Besòs river to the city can be understood from the morphological variable associated with the dyad public space–public transport in the configuration of different scale nodes (punctual interventions) and in their communication and articulation (articulation axes), in which the tramway functioned as a vertebrante or backbone. Borders precision and permeability, urban image consolidation as a functional and visual reference, and enhancement of pedestrian mobility through a balanced road distribution are some of the conditions that will be analyzed in the following sections.

3.2. Morphological Analysis in Layers: Spatial Correlation Between the Tramway, the Urban Fabric, and the Transformation’s Structural Interventions

Based on the vertebrante or backbone role that guided surface transportation has on urban structuring, the analysis of the spatial correlation among the transformation process interventions is conditioned in the first place by the immobility of the tramway route, which provides the potential to become a planning tool that prefigures the form and dynamics of growth [46]. With time, the tramway immobility has the potential to provide greater stability within the processes of urban transformation, because it encourages the implementation of common design standards and criteria in the fabrics through which it crosses. This is due to the physical adjustments that the technical requirements of the guided transportation impose on the surroundings, which are used both to reinforce the relationship between various urban entities to which the tramway provides access, as well as to build a unitary image of the city. The following is a summary of the correspondence between different roads, facilities, and spaces at the points of contact (stations) with the Trambesòs tramway, the environment, and the city’s integrated mobility system (

Table 2. Spatial correlation between the Trambesòs route, the transformation interventions, and other means of transportation as part of the integrated mobility system.

Itinerary	Trambesòs Stops	Street	Transport Connection	Public Space
TramBesòs (T4)	1 Ciutadella/Vila Olímpica	C. Wellington	Línea 4 * (Ciutadella/Vila Olímpica) Bicing	Parc de Carles I Villa Olímpica
	2 Wellington	C. Wellington	Bicing	Parc de la Ciutadella
	3 Marina	Av. Meridiana	Línea 1 (Marina) Bicing	Parc de l’Estació del Nord
	4 Auditori-Teatre Nacional	Av. Meridiana	Bicing	Parc de l’Estació del Nord Teatre Nacional de Catlunya
	5 Glòries	Av. Meridiana	Línea 1 * (Glòries) Bicing Trambesòs (T5–T6)	Plaça de les Glòries Catalanes Mercat de los Encants Av. Diagonal
	6 Ca l‘Aranyó	Av. Diagonal	Bicing	Jardins de Miquel Martí Pol Av. Diagonal Rambla del Poblenou
	7 Pere IV	Av. Diagonal	Bicing	Parc del Centre del Poblenou Jardins de Teresa de Calcuta Av. Diagonal Rambla del Poblenou
	8 Fluvià	Av. Diagonal	Bicing	Av. Diagonal
	9 Selva de Mar	Av. Diagonal	Línea 4 * (Selva de Mar) Bicing	Parc de Diagonal Mar Av. Diagonal
	10 El Maresma	Av. Diagonal	Línea 4 * (El Maresme-Forum) Bicing	Parc de Diagonal Mar Av. Diagonal
	11 Fòrum	Av. Diagonal	Línea 4 * (El Maresme-Forum) Bicing	Rambla de Prim Fòrum
TramBesòs (T5 y T6)	5 Glòries	Av. Meridiana	Línea 1 * (Glòries) Bicing Trambesòs (T4)	Plaça de les Glòries Catalanes Mercat de los Encants Av. Diagonal
	12 La Farinera	Gran Vía de les Corts Catalanes	Bicing	Plaça de les Glòries Catalanes Av. Diagonal Av. Meridiana
	13 Can Jaumandreu	Gran Vía de les Corts Catalanes	Bicing	Parc del Clot Rambla del Poblenou Plaça de la Creu Roja Distrito 22@
	14 Espronceda	Gran Vía de les Corts Catalanes	Bicing	Jardins del Clot de la Mel
	15 Sant Martí de Provençals	Gran Vía de les Corts Catalanes	Bicing	Plaça de la Palmera de Sant Martí
	16 Besós	Gran Vía de les Corts Catalanes	Línea 4 * (Besòs) Bicing	Rambla del Prim
	17 Alfons el Magnànim	Carrer d‘Alfons el Magnànim	Bicing	Rambla del Prim

Source: own elaboration based on multiple sources. * Underground/subway.

).

There are several variations in the configuration of the road network (Layer 1, Figure 4), mainly due to the circulation hierarchy that some roads in the east of Besòs have in the city. According to Table 2, most of the significant connections and articulations occur in the stations located in the Avingudas Meridiana and Diagonal, or in the Gran Via de les Corts Catalanes (Layer 2, Figure 4), which relate to pre-existing elements such as the Parc de la Ciutadella (1879) (previously planned in the Barcelona Reform Plan and Ensanche developed by Ildefons Cerdá in 1860), or to later facilities such as Parc de l’Estació del Nord (1988) or Rambla del Prim (1989).

These roads were consolidated as connectors of the most important public spaces and facilities (urban entities) of the city’s organization, which were recovered and integrated into the design and route of the tramway. Likewise, some of these roads, according to their function and design, are considered some of the most important public spaces in Barcelona, such as Rambla del Prim which connects directly with the Parc del Fòrum, or the Rambla del Poblenou, which connects with the 22@ District (Table 2).

The analysis demonstrates that the relationship between the tramway’s circulation space and the urban entities in their influence areas are determining factors in the construction of long-term connections and more prolific exchanges within the city. This is a result of the increase in the number and quality of such urban entities to which citizens associate and have access, mainly due to bolstering public transportation, and certain identified actions such as pedestrianization or continuity of the urban fabric, which will be analyzed later. In addition, such an increase in the dynamics of each sector favours the emergence of new spaces and activities that overlap with the proposed structure. In turn, they strengthen the integration between existing and new spaces, establishing a network and connectivity logic that is part of an open system (Layer 3, Figure 4).

All of these outcomes suggest that, on the one hand, the efficient development of new interventions is attributed to the intersection and connection between contact points, public space, and transportation, forming a new entity of mediation, convergence, and interaction known as the interface [73,74], from which the dynamics of cooperation between fragments or parts of the city are bolstered. On the other hand, significant spaces of the urban structure such as Avinguda Diagonal, Gran Via de les Corts Catalanes, or Plaça de les Glòries Catalanes, among others, tend to maintain their character and role in the urban layout and network, regardless of changes in the urban model, form, programming and design.

Within the scope of the transformation process of Barcelona´s eastern area and its urban integration into city dynamics, the table above and the following diagram (Figure 4) synthesize the relationship between various types of interventions developed within the internal transformation framework. The top layer shows the main and secondary roads; the second layer shows a correlation between the stations indicated in Table 2 and the most significant structuring spaces; the third layer shows the nodes associated with the tramway route; and the last layer shows their integration in the full and empty spaces of the urban morphology.

In summary, by analyzing these layers, it is possible to affirm that the incorporation of the tramway allowed connection to an urban structure that was incomplete and fragmented, completing the local grid (giving continuity to the guidelines of the original Cerdá Plan). We can identify some of these actions: the incorporation of urban scale axes based on the adopted urban road model [75] (Gran Vía de Les Corts Catalanes); the opening and continuity—as a consequence—of the mountain–sea axes (Bilbao, Bac de Roda, Espronceda streets); the pedestrianization and pacification of traffic in some arteries of the vehicular domain (Rambla del Poble Nou, the edges of the Gran Vía de Les Corts Catalanes); and the recovery of pre-existing spaces and plot openings for new facilities, making the configuration of a new urban reality based on a new and diverse road and programmatic support possible. However, this analysis showed that if this support is not sufficiently permeable, it can disrupt the functioning of the city. This aspect is analyzed in the following section.

3.3. Analysis Conclusions: Urban Permeability in the Integration of Tramway Space into the Immediate Environment

To answer the research question, Figure 5 was developed as a graphic conclusion that helps to argue that the material embodiment of the dialogue between public space and transport infrastructure in the urban fabric at a human scale is conditioned—in terms of the urban fabric´s complementarity, interdependence, and continuity—by two concepts [76]. The first is the riveraineté, which is used to characterize the degree of integration of the tramway within the urban space, that is, the type of established relationship between the transport channel and the edges of the environment, which can be continuous or discontinuous. The second concept is adhérence or adherence and corresponds to the established relationship between the transportation mode and the environment, which can be terminal (punctual) or longitudinal (stretches) [77].

Moreover, we can identify two urban space adaptation actions that intercept the friction between the tramway channel´s longitudinal continuity, which can generate a barrier in the transversal direction, and other daily uses and functions of the urban space: (a) the equitable distribution and pedestrianization of the road space and (b) the construction of a unified city image. These actions complement the major continuity operation associated with the extension and insertion of the tramway (Figure 6) on the Avinguda Diagonal.

In the Trambesòs case, the review of these factors, based on the planned articulation of urban entities, the improvement of the means of transport, and their relationship with the environment, resulted in significant progress both in terms of the tramway adherence with the environment—regardless of the discontinuity that the tramway infrastructure represents—as well as the permeabilization of Avinguda Diagonal.

Broadly, pedestrianization and equal distribution of road space enhanced the flexibility and adaptation of the tramway to the urban fabric. The Sant Marti district, which encompasses the area of influence of the Trambesòs, in 2021, recorded 1,107,455 trips per day. Of the more than 1.1 million journeys recorded, 48% were connections with other districts of the city and 35% were journeys within the district. The majority of trips within districts are made by non-motorized means, and when trips are between districts, most of the pedestrians take public transport [69,78]. This allowed for a situation in which, on the one hand, the urban image is characterized by its permeability, generating a high degree of compatibility between transport functions and existing activities; on the other hand, it enabled relationships of adhérence or adherence, which are mostly based around the tramway stop points and reinforced by their proximity and close links with the most representative spaces, services, and facilities (previously identified in Table 2 and Figure 4).

In the case of the corridor section associated with the Rambla de Poblenou, continuity is achieved because of the permeability generated by the equal distribution of road space along the Rambla, pedestrianization of this axis at the points of contact with the Avinguda Diagonal, and the fact that part of the tramway infrastructure is projected as an extension of public space, as in the case of the central promenade of the Avinguda Diagonal (which is consolidated as an axis of articulation and saturation piece). In addition, tramway infrastructure (catenaries and crossings) contributed to the proportion and order of street configurations.

All of the above contributes simultaneously to the consolidation of the city’s image and functionality, since with the development of transversal relations towards Avinguda Diagonal, based on permeability, adherence, and in balance with the longitudinal accessibility of the tramway´s linear nature, a harmonious spatial framework is established between daily life on a local scale and the broad transportation system requirements, which favours the area´s continuity and urban cohesion concerning the whole city.

In the configuration of the image of the city, the tramway´s fixed and superficial route significantly influences the perception and structuring of the urban landscape, becoming a path that articulates various parts of the city in a uniform and standardized manner [68], in formal, spatial, or functional terms. In this sense, the extension, prolongation, and repetition of its specific characteristics along its route, together with the high degree of visibility derived from its superficial condition, makes it a highly distinguished and identifiable urban piece within the structure of a particular area of the territory (Figure 7).

The fact that the Avinguda Diagonal can be individualized, that is, identified as a singular and independent element in itself, does not imply a dissociation from its surroundings; on the contrary, it becomes a recognizable element that contributes to the identity and legibility of the city [22]. Hence, the double typification, as well as the linear nature of the tramway channel, facilitates the correlation between the backbone or vertebral structure, previous and subsequent punctual interventions, articulation axes, and saturation pieces. This anchoring of the tramway in the territory enables the construction of a collective image that associates the above as common elements of orientation in the city. In this sense, the dialogue established between the tramway and public space along its route contributes to the configuration of an urban identity. Moreover, it provides visual, spatial, and functional permeability; continuity; and connectivity with different urban entities and fragments of the city.

4. Discussion

This article carried out an analysis of the set of interventions (punctual, articulation axes, and saturation interventions) and actions (such as the redistribution of road space and pedestrianization) developed in the urban transformation process east of the Besòs river in Barcelona, as both part of a logic of internal transformation and their relationship with the incorporation of the Trambesòs.

In addition, we outlined the interdependencies and complementarities within the existing dialogue between public space and transportation, which are based on the correlation of each intervention with the tramway, the city’s pre-existing elements, and other urban systems, thus configuring an open network that integrates the analyzed area with city dynamics, the urban fabric, and the city’s image.

Considering this, this article discusses the potential of the tramway as a vertebrante or backbone element of public space, incorporating variables linked to programming, planning, and design of each subsequent intervention from a systemic perspective, in which each element corresponds to the whole and, in turn, integrates and provides greater continuity. Furthermore, it is consistent with one of Conzen’s [45] central urban morphology concepts of “Town-plan analysis” defined as fixation lines that have an “unusual power to influence the morphology of their adjacent areas” [60] (p. 135).

Regarding the tramway as a fixed and guided transport, technical aspects improved the physical and functional conditions of its influence area, allowing the (re)construction of the urban fabric. This is reflected in the Avinguda Diagonal extension, which provided continuity and contributed to the consolidation of the city image, placing the tramway as a means of recognizing and valuing the diversity of the territories through which it passes.

From this perspective, and as part of the process of incorporating the east of the Besòs river into the dynamics of Barcelona, the planned and agreed incorporation of Trambesós aims to create links and bind different urban entities, generating punctual, articulation, and saturation interventions, and providing access to them beneath a pattern of organization and a common image of the city. Accordingly, the development of dialogue between the tramway and various actions, facilities, and public spaces, beyond the material, spatial, functional, and temporal progress, is derived from the emergence of collective spaces that are part of a system that affects daily life. Likewise, given the relationship between public spaces and transportation, the tramway acts as an extension of the former. Therefore, it must be planned and designed as a systemic network seeking to avoid ruptures that derive from the immovability condition of guided means such as this one.

From the above, the contribution of the tramway and its relationship with public space as a tool for making the city is dictated by (a) the possibility of having a growth pattern that allows projection with a certain consent on urban development based on public policies and (b) the possibility of creating a flexible (multi-purpose) urban environment conducive to spontaneous and diverse encounters and exchanges. These exchanges are related to the quality and quantity of urban instances (places and activities) to which the tramway articulates and provides access as part of a structural system.

In this order of ideas, the reinsertion of the tramway is not only projected as a new complementary means to the existing transportation system but also as an opportunity to dynamize, interrelate, and connect a previous vision, which in many cases lacked appropriate physical support, with future needs, both under a structure of order and local medication that provides a greater sense of urbanity.

Additionally, the urban network concept, under which the internal transformation logic and every type of intervention connected with the tramway are framed, entails the establishment of spaces of interaction (interface) that give rise to cooperation dynamics between fragments and parts of the city. Thus, it is important to value and recognize the potential of these contact and interaction points between transportation and public spaces as a new entity [68], enabling a dialogue between the different systems of the city [73,74]. The above can be established as a more concrete version of the node–arc concepts proposed in the graph theory applied to the analysis of urban road networks [24].

Although the results come from qualitative analysis, they are consistent with expectations when contrasted with quantitative evaluations, such as analyses that combine traditional census, mobile phone, and OSM data. One example is the study by Graells-Garrido et al. [78], where areas such as Poblenou, Diagonal Mar, and the Front Marítim del Poblenou stand out with statistically significant values obtained through Geographically Weighted Regression (GWR), which evaluates mobility attractiveness towards neighbourhoods characterized by good accessibility indicators to retail amenities.

Although this study focuses on qualitative analysis, this type of approach is crucial in exploratory stages of analysis to understand how transport infrastructures, such as the Trambesòs tramway, reconfigure and articulate public space. Accessibility is defined here beyond conventional metrics, encompassing its capacity to generate urban cohesion and the articulation of the urban fabric. Thus, the Trambesòs tramway is analyzed as a structuring element that reconfigures spatial and social relations in previously fragmented areas, contributing to urban sustainability [3,24].

While quantitative studies allow us to measure aspects such as service frequency or passenger numbers, the qualitative approach employed offers a perceptive understanding of how public transport can act as a catalyst for changes in urban morphology, creating new centralities and fostering social interaction. As mentioned in the introduction, the tramway not only facilitates mobility but also acts as an extension of public space. Furthermore, as highlighted in the methodology, the layered analysis of urban interventions demonstrates how accessibility goes beyond physical metrics, also addressing the impact on social dynamics and urban morphology. This qualitative analysis precedes the quantitative studies, which can apply tools such as Space Syntax [79] or gravity models to quantify accessibility impacts, providing an indispensable initial framework.

Another quantitative analysis that can be considered representative of the findings in this article, and more in line with the spatial morphology branch of urban morphology established by Berghauser [79], is the Space Syntax analysis. Clua et al. [76] used the Visual Clustering Coefficient (VCC) to show how interventions in the urban grid of the study area exhibit values that indicate patterns of visibility and urban accessibility, comparable to the uniqueness and richness of the octagonal form contributing to the perceptual experience of the Eixample. In this regard, Clua et al. [76] highlight, citing Sola-Morales, how the diagonal within the grid is a “synthetic element that allows for an instant understanding of the two directions of the grid” and “an understanding of our location as individuals moving through the whole”. In addition, to these studies, Colamino [80], Vilà [81], Speranza [82], and Mercadé [83] complement the qualitative results obtained at this stage of the research and validate the innovative nature of this type of study. By contributing methodological and practical elements to knowledge, qualitative approaches complement and expand the scope of quantitative studies conducted in this field of study. This triangulation exercise with quantitative methodologies confirms that for the area studied, the proposed methodological approach provides initial arguments for developing diagnostics, making decisions, and even conducting foresight in urban planning. This is linked to how interventions resulting from urban mobility can both restructure and rejuvenate the experiences of citizens associated with urban forms.

Consequently, the results also allow us to move forward in the study of the relationship between public spaces and transportation, delving into the implications that both have on urban issues [84]. Concerning urban regeneration, the link between public space and transport also contributes to the search for new forms of reliance or reliance [38,39,77], appropriation, and cohesion in the city. This may ultimately lead to more sustainable city models based on the development of flexible and adaptable solutions that can evolve with urban dynamics, user needs, and the efficiency of the urban mobility infrastructure [85]. In this context, transportation, particularly guided transport, such as the tramway, can open new paths in the search for innovative ways to address problems related to both physical and social urban structures, such as fragmentation, socio-spatial segregation, and loss of identity. All of this is to promote equal access to goods and services, diversity and quality of public space, and economic and social balances in the territory. This situation has been reflected in the gradual increase in urban density in the area known as 22@, which is located within the Sant Marti district, where the Trambesòs area of influence is concentrated. This area has gone from a buildability coefficient of 2.0 m²st/m²s industrial to 3.2 m²st/m²s mixed, going from being a district with a predominantly industrial use to a diversified one with 10% social protection, 10% equipment, and 10% green areas [69] (p. 15).

Barke [86] (p. 18) stated that the relevance of an urban morphology study is directly linked to the formulation of policies regarding aspects such as urban sustainability, energy efficiency, crime patterns, and public health. The findings provided in this article methodologically enrich the analysis by defining a process that helps identify the impact of transport sustainability by focusing on the social dimension. Studies, such as those conducted by Grande-Ayala [87], show how the well-planned physical integration of BRT systems into the urban fabric enhances accessibility to basic urban facilities in neighbouring sectors, and those by Alam et al. [88] reflect the influence of this dyad of public space–public transport in determining travel mode preferences.

Accordingly, since the analysis is focused on physical and morphological aspects, it represents a partial vision of the interpretation of urban transformation via the dialogue between transportation and public space, as it shows limitations in the social, economic, and cultural aspects on which the development of each intervention has depended. Although different studies have pointed out that an urban planning model that seeks urban vitality promotes socioeconomic activities that tend to be more abundant and spatially positive in more compact urban areas [89,90], the role of transportation in these dynamics still needs to be unpacked. The above projects an interesting line of development from which to advance the assimilation of more sustainable transportation models anchored in the socioeconomic realities of each context.

Aspects such as inequality and precariousness, albeit more determined in other contexts, are significant when defining, planning, and designing this transformation process. Tackling the search for continuity and urban cohesion through an analysis that goes beyond the spatial dimension, including aspects such as participation and appropriation, is still necessary and points towards a more equitable city. Furthermore, without overlooking the need for institutional planning at the city level, these aspects play a significant role in terms of governance and democratization of the urban space, as they allow for the effective transfer of decision-making processes from the central power to the local administration and subsequently to the community in general. The tramway, as a connecting and energizing element, could acquire new potential in participatory scenarios.

5. Conclusions

Based on the vision of the city as a result of infrastructure network expansion, infrastructure capacity depletion, and continuous public space predominance in the daily life of cities [91], the construction of a new public transport infrastructure allows not only the extension of urbanization during a period of growth (generating unfinished urban spaces that condition the city´s future) but also the reinterpretation of the public space–public transport dyad as a model of urban transformation from within, that is, of the rearrangement of existing physical–spatial conditions. This contributes to generating a more balanced territory and an articulated, permeable, and continuous urban fabric that mediates between the multiple layers and scales that shape the form of the city, connecting pre-existing spaces, and giving rise to new interventions.

Because of ongoing research and because some interventions are still under development, the analysis of both the urban transformation of the east of the Besòs river and the development of a public space network in correspondence with the tramway can be interpreted as elements that have contributed to the planning and evolution of this area’s morphological integration. Furthermore, although it is outside the initial scope of the study, it can be deduced that the punctual interventions, articulation, and mainly the saturation pieces derived from the introduction of the tramway have significant implications in the city’s economic and social dimensions, as well as in other aspects of urban reality, as they contribute to the configuration of a continuous territory that overlaps the imposed administrative barriers and physical limits.

As previously mentioned, the integrated planning of the set of interventions and actions within the framework of the Trambesòs project resulted in significant improvements, associated not only with the restructuring of existing spaces but also with the production of new urban entities. In this sense, the planning, programming, and design of networked urban entities and spaces represent a valuable tool that (a) contributes to the connectivity of the city [38], establishing links that foster the number and quality of exchanges associated with the possibility of people’s access to goods, services, and urban functions, and (b) promotes the emergence of new interventions and socioeconomic dynamics that, together with other measures, contribute to the regeneration of a given area. Therefore, it can be concluded that the tramway project has continued to be a significant instrument for the construction of coherent, harmonious, and cohesive urban spaces.

Finally, it is important to complement the analysis and qualitative findings of this study with a quantitative approach, which nourishes the evaluation parameters by establishing model relationships between the elements studied. This would also make it possible to develop a methodology that can be applied to other contexts. In addition, this study should advance the measurement of spatial mismatches in terms of underutilization and overutilization of urban spaces (spatial autocorrelation) [89,90]. This can generate imbalances and discontinuities both at the local level, with the neighbourhood’s daily life, and at the urban level.

At the methodological level, the introduction of quantitative measurements in the understanding of city image and urban morphology would allow the methodology initially developed for Trambesòs to be replicable in other cities that have implemented or are in the process of implementing guided transport systems (tramway and BRT, among others). The relationship between public space and transportation has been and continues to be central to urban regeneration processes that seek to strengthen the cohesion of the urban fabric, which could also be adapted to analyze different transport–public space integration projects, mainly in metropolitan areas with discontinuous or fragmented growth, and for projects that aim to create new urban centres by improving the accessibility and quality of public space.