Morphological Dynamics of Tram-Led Regeneration: A Space Syntax Study of the Trambesòs Line in Barcelona

Abstract

Surface-guided tram systems are increasingly being recognised not only as mobility instruments but also as agents of urban regeneration that reshape spatial and social dynamics. This study evaluates the configurational impact of the Trambesòs tram in Barcelona on accessibility, integration, and urban cohesion within the Levante del Besòs area. A Space Syntax analysis was conducted in UCL DepthmapX for axial map analysis and visual graph analysis within a 500 m radius around each station. Three typologies of intervention (site-specific, articulation axes, and saturation pieces) guided the assessment. This analysis shows that Avinguda Diagonal and Avinguda Meridiana are primary structural corridors, while stations Glòries, Ca l’Aranyó, and Pere IV recorded the highest accessibility and visual openness. The results indicate that targeted interventions have positive impacts on the Space Syntax metrics regardless of their spatial centrality, highlighting the critical role of this diverse intervention typology in shaping the study area’s spatial configuration and influencing a hierarchy of social appropriation and use. It is concluded that the Trambesòs tram and associated urban interventions have jointly enhanced centrality and permeability in key sectors, and specific peripheral enclaves have local functioning. These findings, focused on spatial and morphological patterns, may support future interventions in urban design and mobility planning. Although the analysis centres on spatial configuration, future research may integrate socioeconomic variables to broaden the understanding of regeneration processes.

1. Introduction

Surface-guided public transport has significantly reshaped territorial dynamics within broader debates on contemporary urban transformations. This is largely because of its capacity to articulate and structure the multiple transformations associated with the regeneration process within a physical–temporal framework of intervention grounded in the ideal of public space as polysemic support for urban life [1]. In this regard, the tram emerges as a structuring axis of the urban system, enhancing the connectivity between segregated areas and promoting a more integrated spatial structure. Beyond its structural role, it is essential to acknowledge that trams, and overall, surface-guided public transport play a vital role in the daily mobility of urban populations. This functional dimension positions it as a key component within a sustainable mobility system where multiple transport modes coexist and complement each other. Its contribution is reflected in its improved accessibility, reduced congestion, enhanced intermodality with active modes, and strengthened territorial cohesion. Several studies have emphasised this dimension, highlighting its role in energy efficiency, operational flexibility, urban equity, and sustainable urban development [2,3,4]. The importance of electromobility systems in cities has been analysed in the literature, and their usefulness in mobility and sustainability has been proven [5]. Thus, articulation between public transport and urban morphology is proposed as a key strategy for strengthening both accessibility and urban cohesion.

The role of public transportation in urban planning and design has evolved significantly, moving beyond a reductionist approach, which focuses primarily on meeting mobility and accessibility demands, toward a more comprehensive framework that positions it as an instrument of urban prefiguration. In this expanded role, public transport not only responds to urban growth but also guides it by shaping new urban dynamics through its infrastructure and empowering cities with a renewed sense of urbanity. This shift has had direct implications for inhabitants’ accessibility, both in terms of the number and quality of urban instances they can reach [6,7], and for urban cohesion and territorial balance, which are key urban ideals to be pursued and promoted. Thus, transportation has emerged as an agent of urban regeneration, capable of improving accessibility, generating new centralities, and transforming the spatial patterns in which it is embedded.

The evolving nature of urban accessibility issues, particularly those that determine and measure the link between mobility and accessibility, has a direct impact on the domain of everyday life where mobile objects gain meaning in a lived reality [8,9]. This represents a significant transformation in understanding and complementing the traditional supply-oriented perspective. Contemporary debates on mobility—as expanded later in the theoretical review—have repositioned mobility as a dynamic lens for interpreting urban life.

Accessibility is understood as one of the key ideals of contemporary urbanity [10,11,12], essential for equity, sustainability, and urban quality of life [13]. Beyond being a purely functional indicator, it serves as a mechanism for quantifying urban transformations and assessing their territorial impact. The sustainability of a given territory is largely dependent on the dynamics generated by such transformations and the extent to which higher levels of accessibility correlate with resource efficiency as well as the effective use and distribution of goods and services that structure, articulate, and support urban life [14].

From a morphological perspective, the way the mobility infrastructure modifies the urban grid indicates the relationship between transportation and urban patterns. In this sense, the Trambesòs case demonstrates how intervention techniques have resulted in distinct morphological geo-layers organised at three levels: punctual interventions, articulation axes, and saturation zones [15].

This study builds upon the qualitative framework developed in the article “(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” [15], which identified three typologies of urban intervention: punctual interventions, articulation axes, and saturation zones, in the context of the Trambesòs tram infrastructure. These typologies reflect multiscale logic: punctual interventions activate local contexts, articulation axes connect dispersed interventions, and saturation zones consolidate them into integrated urban nodes. These three typologies were defined as complementary strategies within the broader logic of internal urban transformation. Punctual interventions refer to localised and small-scale actions in public spaces or facilities that activate immediate surroundings and generate nodes of activity and spatial reorganisation. Articulation axes are linear corridors that connect different urban sectors and link dispersed interventions across territories, thereby enhancing the morphological continuity and transversal mobility. Saturation pieces are characterised by high functional and symbolic density and result from the agglomeration of multiple punctual interventions and articulation axes within a larger area, consolidating metropolitan nodes of integration, and spatially unifying previously fragmented sectors. This classification provides a framework to analyse how each intervention type contributes to accessibility, integration, and urban cohesion.

This study focused on the morphological analysis effect of public transport on urban regeneration, highlighting the relationship between tram stops, adjacent public spaces, and their contribution to urban life, fostering social cohesion. This study incorporates configurational and urban morphological analyses around the Trambesòs tram infrastructure. Urban morphology, also referred to as urban form or urban geometry [16], focuses on the physical layout and spatial structure of the city, analysing how streets, plots, buildings, and public spaces are configured and composed [17]. Although some scholars incorporate socio-cultural and economic dimensions, the discipline remains rooted in the study of the physical attributes and spatial structure of urban environments [18]. Urban morphology provides the foundational framework for urban syntactic analysis, as it establishes the formal and spatial components for understanding how spatial urban form are organised and interrelated, revealing the different patterns that shape an urban area, e.g., connectivity between spaces or streets, hierarchies, and scales in the organisation of the urban fabric. Building on this morphological foundation, we apply a Space Syntax-based analysis with the UCL DepthmapX 0.8.0 tool for a quantitative perspective of the influence of the tram on key nodes of urban life, i.e., public spaces and facilities, particularly those linked to public spaces and urban infrastructure. Analysis of the urban form provides insights for planning, design, and the evaluation of urban transformation. While this stage focuses on the spatial and morphological configuration of the urban fabric in relation to tram infrastructure, socioeconomic dimensions and land-use are equally critical for understanding the complexity of the cities. Future research could integrate these dimensions to deepen the understanding of how accessibility, equity, and urban transformation evolve alongside tram-based interventions.

To guide this analysis, the study is structured around the following research questions, which seek to bridge the previously developed qualitative framework with a quantitative spatial analysis: How do different types of urban interventions (punctual interventions, articulation axes, and saturation pieces) contribute to the emergence of new centralities and urban cohesion? How does the Trambesòs tram infrastructure influence urban integration, choice, and axial and visual connectivity in the Levante del Besòs? How do Space Syntax metrics or urban analysis relate to the 3 types of intervention and support the validation and refinement of the intervention logic proposed?

These questions provide an analytical foundation for a configurational approach that integrates the morphological theory with empirical spatial data. By focusing on the socio-spatial effects of public transport on urban regeneration, highlighting the relationship between tram stops, adjacent public spaces, and their contribution to urban life and social cohesion. Building on this framework, this study aimed to evaluate the spatial impact of the Trambesòs tram on accessibility, integration, and urban cohesion in the Levante area of the Besòs River, with special attention paid to public spaces and urban facilities that were part of the area regeneration and restructuring process and part of the internal logic of intervention.

This paper is organised as follows: Section 2 presents the literature review. Section 3 describes the methodology with the study area and explains the two types of analysis used and the metrics concepts of Space Syntax, UCL DepthmapX tool. Section 4 presents the results of the urban spatial analysis and relate the urban metrics with the tram stations and the 3 types of intervention. Section 5 discusses the implications of urban regeneration. Finally, Section 6 presents conclusions and recommendations for urban planning.

2. Literature Review

The analytical framework developed by Hillier and Hanson through Space Syntax provides a means of understanding the relationship between spatial configuration and urban mobility while offering tools for evaluating accessibility and cohesion in urban environments [19]. Based on this theory, the University College of London (UCL) developed the DepthmapX software [20]. This approach argues that the design of urban space directly influences movement patterns and social interaction, an idea denoted by Hillier as the “theory of natural movement” [21]. Under Natural Movement Theory, different street grids generate distinct pedestrian flows almost independently of specific attractors. Space Syntax theory has allowed the development of sub-theories that emphasise the complexity of urban systems, as “Movement Economy” argues that urban socioeconomical activities reinforce this potential movement, while “Pervasive Centrality Theory” suggests that core urban functions are not limited to defined centres but instead spread across the entire urban fabric, creating a more complex and interconnected patterns than polycentric models [18,22].

Space Syntax provides a framework for analysing urban form by quantifying perceptual accessibility and movement potential through core axial maps metrics [23] (these parameters will be explained in the methodology). By translating complex street configurations into measurable indicators, it enables urban diagnostics of walkability and mobility patterns. Rather than modelling individual “pedestrian choice making” [22], it uses topological analysis to reveal how cities function spatially. It evaluates how users navigate the urban fabric through turns and linear continuity, beyond straight-line distances or direct links. Researchers highlight its relevance to sustainability and mobility; Yamu et al. showed that highly integrated streets and pedestrian-oriented urban fabrics encourage walking, cycling, and transit use, reducing car dependence and supporting more sustainable, inclusive, and accessible cities. They argue that the configuration of buildings and street layout shape social interactions and subsequent socioeconomic activities and that Space Syntax provides tools of analytical techniques to correlate spatial metrics, like integration and choice with diverse socioeconomic datasets [23].

According to Hillier, spatial structure determines the strategic use of land and flow of movement within the city [24,25,26]. Space syntax methodology relies on topological representations and deliberately omits metric dimensions, such as heights and land-use data [27] to isolate urban configurational effects in terms of natural movement [22]. Cities are complex systems, where socioeconomic variables can be introduced as multiple variables into morphological analysis. Beyond its methodological tool, Space Syntax has evolved into an interdisciplinary urban theory. Krenz et al. analysed over 700 Space Syntax Symposium papers (1997–2019), tracing the development of Space Syntax studies from foundational concerns of spatial configuration, movement, and accessibility to themes, such as social inequality, public health, urban resilience, and digital technologies [28]. Space Syntax and spatial modelling have become a basis for studies on how built environments influence and reflect urban behaviours, socioeconomic dynamics, and sustainability.

Parallel to morphological and configurational analysis, tram-led urban regeneration processes have also begun to be examined from a socioeconomic perspective. Several studies have pointed out that the benefits associated with accessibility gain more meaning when considered in relation to the redistribution of opportunities, services, and symbolic capital within urban space [29]. In various Latin American and European contexts, tram corridors have been shown to serve as effective platforms for spatial justice, especially when embedded within inclusive governance frameworks and participatory planning [30]. In this regard, the value of such infrastructure is not limited to traditional indicators, such as number of trips or territorial coverage, but lies in the number and quality of social, economic, and symbolic exchanges they enable.

Consecutively, these exchanges reflect and influence the socioeconomic conditions of the urban environment, determining who can effectively benefit from regeneration processes [31,32]. Recent studies in cities, such as London, Medellín, and Barcelona, have shown that transport-led interventions can foster economic revitalisation and social cohesion but may also generate unintended effects, such as gentrification or spatial fragmentation, if not accompanied by housing, governance, and equity policies [33,34]. These findings highlight the need to understand urban regeneration beginning with the lens of infrastructural components and further continuing with socioeconomic dynamics for a full understanding of urban life.

While this study focuses on spatial configuration, it acknowledges that socioeconomic dimensions offer significant analytical value for understanding urban cohesion as a complementary and necessary dimension within contemporary urban regeneration processes.

Studies across various contexts have shown that Space Syntax provides core spatial indicators that can be integrated with walkability index simulations, empirical observations, GIS-based land-use data, or computational tools to capture how street-network configuration influences movement and accessibility. Omer and Kaplan incorporated integration and choice into agent-based simulations to predict pedestrian volumes [35]. Morales et al. [36] demonstrated correlations between angular integration and choice with travel-time accessibility in Guatemalan cities, highlighting Space Syntax’s utility as a low-data planning tool. Esposito et al. contrasted axial metrics with actual pedestrian routes gathered in Bari’s Murat district [37]. Other studies evaluated park accessibility using global and local integration, a “synergy” index for perceptual legibility, and a spatial-efficiency metric [38]. Yang and Qian outperformed purely configurational models in Xi’an by integrating segment-based syntactic data with an AHP-weighted GIS-MCDA of land-use attractors [39]. In Hajjah, Palestine, Qanazi researchers overlaid integration, choice, and connectivity maps with the locations of clinics, schools, parks, and markets to define syntactic catchments, differentiating facilities serving local versus through-movement flows using Space Syntax analysis integrated with GIS and agent-based modelling [40]. These studies position Space Syntax as a diagnostic tool for analysing existing urban form but also as a prescriptive system for designing cities that are more sustainable, inclusive, and resilient.

This perspective allows for a broader understanding of improvements beyond the initial positivist perspective, often associated with the intrinsic benefits of implementing mass public transport systems, such as trams, public spaces, and facility upgrades, which were initially part of a broader urban transformation process and later became embedded in an urban itinerary. Within the systemic interaction between these elements, which are considered part of an integrated urban transport system, each urban instance has the potential to function as a node of articulation and exchange, extending its influence through the flow of public transport, which is amplified by the increasing demand for access to such places. In this sense, the tram operates as an organising pivot of the urban spatial configuration and the emerging urban environment [41], helping to rectify spatial discontinuities and/or disjunctions between urban issues and multiple instances within a shared spatial framework.

The analysis of the current state of accessibility, following the completion of the urban transformation project and independent of pre-existing conditions, must be understood within the context of the Trambesòs, which is closely linked to the redevelopment of an obsolete yet centrally located industrial area in Barcelona. This land was redefined as a strategic urban reserve to accommodate city growth and foster the new economic and social dynamics tied to the knowledge economy. In this context, most research addressing the challenges in the Levante area of the Besòs River focuses on accessibility as an indicator, largely detached from the broader process of urban restructuring, and more commonly associated with the principles and implications of the compact city model [42,43,44,45,46,47].

In addition to its function as a mobility infrastructure, the tram is conceived as a structuring agent that reorganises urban form and redefines spatial hierarchies. Its implementation generates new centralities, improves the legibility of the urban environment, and promotes the integration of previously fragmented sectors [17,48].

This perspective aligns with a contemporary vision of urban sustainability, in which public transport—alongside its ability to reduce emissions and energy consumption—fosters a more equitable, accessible, and cohesive city. In this sense, sustainability is understood as a multidimensional quality that articulates environmental efficiency, spatial justice, and urban quality of life [29,49].

Authors, such as Dupuy [50] and Sennett [10], have highlighted how transport corridors can act as structuring elements of the territory, while Richer [51,52], Diaz [53], and others described these nodes as urban interfaces or interchange points where mobility flows, urban functions, and symbolic meanings converge.

Mobility, understood as a lived and symbolic dimension, has been revalued by the “mobility turn”, which proposes its use as a central analytical category for interpreting urban transformation [9,54]. As developed by authors, such as Tim Edensor [55], this approach redefines mobility and accessibility not merely as objects of study but as theoretical frameworks for understanding contemporary urban life. This shift has encouraged new methodological approaches for analysing urban, social, and spatial phenomena through the lens of physical and symbolic exchange relations involving people, objects, and ideas. These relations are expressed through the links between public spaces, transport systems, and urban facilities.

Likewise, the integration of transport and public space contributes to the construction of a coherent urban image. Authors, such as Brandão [56] and Lynch [57,58], have emphasised the importance of spatial continuity and symbolic legibility in shaping urban identity.

These perspectives complement the configurational approach of Space Syntax by situating spatial analysis within a broader framework that incorporates perception, morphology, and symbolic structure. This theoretical integration enables the tram to be approached as an instrument of sustainable urban regeneration, with effects on both accessibility and territorial cohesion [30].

3. Methodology

The study was focused on the Trambesòs tram network in Barcelona, considering its impact on spatial configuration and patterns of potential pedestrian mobility. A 500-m radius was delimited around each tram station, following international standards for pedestrian accessibility [59,60], commonly used in transit-oriented development (TOD) and urban morphology studies. This threshold is supported by empirical findings from transport and urban morphology research [61,62], which indicate that 500 m is both a widely accepted planning standard and a behavioural benchmark observed in dense urban contexts.

Additionally, local studies in Barcelona have demonstrated that access to public transport within a 500-m radius significantly influences walking behaviour and urban accessibility [63]. This range allows for meaningful analysis of accessibility continuity and potential pedestrian catchment areas around tram stations. Transitional areas between different urban morphologies were included to evaluate these criteria, as part of a broader system.

Urban morphological analysis seeks to understand the underlying spatial logic of urban fabrics by examining how the built environment is structured and how different elements, such as streets, blocks, open spaces, and buildings, relate to one another [17] and underscore the need to understand the reciprocal relationships among them [18]. It emphasises configuration, the way spatial systems are arranged and connected, rather than focusing solely on land use or architectural form. This analysis can be performed in Space Syntax, which provides a set of tools for the quantitative analysis of spatial relationships, offering insight into how urban form may influence patterns of movement and accessibility. Space Syntax lies in its capacity to reveal both local and global spatial properties through metrics that describe how space is embedded within a larger system. These metrics are defined forward and are used in this research as they are the core of morphological analysis.

Herein, the urban morphology of the study area was determined with a syntaxis analysis of the space to assess the effects of the Trambesòs tram on accessibility and urban cohesion. UCL DepthmapX software was used for the determination of the Space Syntax metrics: integration (HH), axial connectivity, choice, and visual connectivity. UCL DepthmapX software is based on Space Syntax theory and supports quantitative and configurational methodologies. It enables the topological interpretation of spatial relations, identifying emergent patterns of accessibility, visual reach, and spatial hierarchy within the urban network [23,25]. This approach leads to a proper evaluation of the link between urban morphology, accessibility, and cohesion through a topological analysis of the spatial network adjacent to the Trambesòs for the identification of barriers, discontinuities, and spatial hierarchies that affect urban connectivity.

The study was structured around three types of urban interventions identified in previous research [15], namely punctual interventions, articulation axes, and saturation zones-, to establish a relationship between them and their impact on urban cohesion. These categories serve an analytical function by enabling the spatial differentiation of intervention scales and their respective impacts. Punctual interventions were examined as localised nodes of transformation, articulation axes as connectors that structure continuity across the urban fabric, and saturation pieces as integrated systems that concentrate and unify multiple interventions. This typological framework supports a configurational analysis developed through Space Syntax. The quantitative analysis and its correlation with the three urban interventions allowed for the visualisation and measurement of how the tram has affected urban movement, revealing shifts in urban accessibility and the creation of new centralities. This approach also enables empirical validation of the intervention logic proposed in a previous qualitative study by assessing the spatial performance of each typology through Space Syntax metrics. To achieve this, axial map analysis and visibility graph analysis (VGA) were applied with UCL DepthmapX software to the area surrounding the Trambesòs line. Both were conducted following standard practices in the Space Syntax methodology and foundational metrics within Space Syntax theory [23,64,65], and the default settings were applied, using topological distance (step depth) as the metric for analysis.

Space Syntax provides different analytical tools to understand spatial configuration. Two of its primary methods, axial map analysis and visual graph analysis (VGA), focus on different dimensions of spatial experience: one based on potential movement through axial lines, and the other on intervisibility within a space. Axial map analysis is a method used to examine spatial configuration through a network of straight lines that cover all accessible spaces within an environment (urban or architectural). It is particularly effective for analysing movement potential, connectivity, and spatial hierarchy.

Axial map analysis was performed to predict flows, identify structural corridors, and evaluate spatial connectivity. This analysis is structured on the urban system through straight lines that describe the longest and most direct possible paths without visual interruptions and offers a configurational reading of the urban structure. The axial map analysis was performed in DepthmapX with a global radius (radius = n) to capture the full extent of topological relationships within the area of the Trambesòs line [21,66]. In this study, the analysis of articulation axes, i.e., streets, metrics, and axial maps were built from the fewest-line map (minimal) setup in UCL DepthmapX, which is the most conventional configuration for outdoor analysis (i.e., urban analysis). This process smoothens segmentations and counts by defining the axes as the longest straight lines in the study area [66]. Tram stations and the main public spaces were analysed using an all-line map setup in UCL DepthmapX, in which the axial metrics were defined as the average of the parameter values of the segments crossing the spot. This aims to avoid the assignment of axial metrics that represent a main street to specific spots; otherwise, by using the fewest-line map (minimal) setup, different spots on a street would end up having the same metrics. In this study, axial map analysis was performed using the following metrics:

• Integration (HH): This metric is based on the concept of closeness centrality, which measures how near/far a street (i.e., axial line) is from all others in the system [25]. Integration measures how easily a space, represented by an axial line, can be reached from all other spaces within the system. It is a global or local indicator of accessibility, depending on the radius applied. High integration values signify that a space is centrally located and requires fewer directional changes to reach from other axes. In urban analysis, high integration axes are often the most integrated streets and typically correspond to main boulevards or thoroughfares that facilitate movement and orientation across a wide area.
• Choice (normalised to a range between 0 and 1): This metric is based on the concept of betweenness centrality [21,26,65,67], as it captures the interconnection and mediating function of a given segment. Choice measures how often a segment (or axial line) is used as part of the shortest routes connecting all possible pairs of spaces in a spatial system. It reflects how strategically important a space is for the distribution of movement. Choice is a measure of how many times a space is likely to serve as the shortest route between other spaces. It reveals the movement distribution potential of a segment, identifying spaces that support flow and transition rather than destination or centrality. For every pair of spaces in a system (e.g., A → B, B → C, A → D, etc.), there are the shortest possible paths to connect to every other space (i.e., with the fewest turns or steps). Choice counts how many of these shortest routes pass through a given line. Therefore, if a line appears frequently in the shortest paths between many other spaces, it means that people are likely to pass through it when moving between different parts of the system, and it functions as a strategic connector, like a bridge, corridor, or shortcut.

Axial Connectivity: It counts direct intersections and is interpreted as the count of direct intersections [25]. It is a local measure that counts the number of immediate axial lines directly connected to a given line. It reflects the direct relational complexity of a space/axis. A line with high connectivity is one that intersects with many others, suggesting a high potential for local interactions and spatial permeability. However, high connectivity does not necessarily imply global importance or centrality.

Overall, while integration emphasises spatial accessibility and centrality across the entire system or within a defined radius, choice captures the strategic significance of a line as a transit route. In contrast, connectivity highlights the direct, local density of spatial links.

In addition, VGA was applied to assess visual accessibility and spatial perception in areas adjacent to the tram alignment. The VGA allows for the evaluation of the visual and pedestrian-scale properties of the visibility network and provides insight into how the spatial configuration can influence permitted movements [68]. It examines the visual properties of space based on isovist fields, which represent what is visible from a specific point. This method is particularly suited to architectural environments where spatial experience is shaped by visual exposure and intervisibility rather than movement paths. VGA was performed using the following metric:

• Visual Connectivity: It measures the number of locations (grid points or nodes) that are directly visible from a given point in space. This metric reveals how visually open or enclosed a space is. High visual connectivity suggests that a space affords broad visibility, which can support wayfinding, surveillance, and social interaction. It is especially relevant in architectural settings, such as museums, schools, hospitals, or public squares, where spatial experience and orientation are mediated through visibility.

To break down the abstraction of these metrics, random examples are herein used to differentiate their practical meaning and what makes them unique and relevant to analyse potential path movements and space openness.

The first case (Figure 1A) is a ring road at the periphery of a city that may have low integration because it is far from many parts of the network, and it takes multiple steps or changes in direction to reach it from most locations in the city. Since this peripheral segment is part of the shortest path for many such origin–destination pairs, it gains a high choice value. Additionally, because it intersects with many radial streets, its axial connectivity is also high. It means that this ring road plays a critical role in movement distribution, serving as an essential bypass or connector and underscoring its importance in movement distribution, even if it is not centrally located within the overall system.

Another scenario (Figure 1B) is a narrow alley that connects two major streets in a central and dense urban block. As it only connects two streets, its axial connectivity is low; however, it forms the shortest route between multiple pairs of origins and destinations across the urban grid. As a result, it has a high choice value, meaning that many people are likely to use it as a shortcut through the block. Also, it has a high integration for its centrality in the study area.

Finally, the last scenario (Figure 1C) is a local street with many small cul-de-sacs branching from it in a suburban neighbourhood. This main local street may connect to many small streets or driveways, giving it high axial connectivity. However, it has low choice because it does not lead to or lie between important destinations, and therefore, it is rarely part of any shortest path connecting distant areas. People mostly arrive there as a destination, not to pass through on their way elsewhere. In this case, integration will depend on the centrality of this local street to the whole space.

Through these spatial metrics, patterns of connectivity, accessibility, and mobility were identified to reflect the transformation of the territory and establish correlations with the urban interventions.

The core of this study is the area of the Trambesòs tram and neighbouring Barcelona (Figure 2), which is in the Levante area of the Besòs River. The Trambesòs tram corridor lies within the San Martí district, an area with a population of 253,000 inhabitants [69]. It is embedded in the Eixample urban structure, characterised by a regular orthogonal grid of urban blocks [70].

The Trambesòs stations were analysed with a 500-m radius (Figure 2A), and the main streets and public spaces are depicted in Figure 2B. The map presents the set of neighbourhoods traversed by the Trambesòs tram line, namely Villa Olímpica de Poblenou, El Poblenou, Diagonal Mar I el Front Marítim del Poblenou, El Parc i la Llacuna del Poblenou, Provençals del Poblenou, and El Clot, which have been part of urban regeneration initiatives. This area was part of the redevelopment of the seafront and the implementation of the 22@ innovation districts [71], both reshaping the spatial and functional dynamics of the area. The area illustrated in Figure 1B along the Trambesòs tram line reflects the orthogonal urban fabric of San Martí, characterised by a mix of residential, cultural, recreational, and institutional uses.

The public spaces analysed in this study, including key parks and structural streets adjacent to the tram corridor, were selected based on the selection and classification of prior studies. Figure 2B highlights the most representative public spaces surrounding the tram corridor for quantification, with Space Syntax analysis of their spatial performance within the study area. This selection allows for a comparative reading of spatial metrics in relation to the type of intervention that links morphological structure with urban design strategies.

To synthesise the research process, Figure 3 illustrates the methodological workflow developed in this study. First, a qualitative morphological analysis identified and classified the existing intervention typologies. Building on this taxonomy, the second phase formulates spatial hypotheses about how each intervention type generates new centralities. In this study, these hypotheses are tested quantitatively using Space Syntax (UCL DepthmapX) to evaluate the spatial and morphological impact of tram-led transformations in terms of accessibility and urban cohesion. Forth, the cross-validation confronts the three types of typologies with the quantitative metrics. These analyses focus on the physical and functional restructuring of the Levante area of the Besòs River. This methodology can be extended by incorporating temporal dynamics, examining how intervention effects evolve across different timeframes and by integrating socioeconomic, demographic and cultural variables to capture broader dimensions of urban cohesion and resilience.

4. Results

4.1. Trambesòs Corridor: Urban Transformation and Spatial Accesibility Context

The Levante area of the Besòs River in Barcelona has undergone a significant process of urban transformation in recent decades driven by regeneration strategies aimed at improving key urban indicators, such as accessibility, integration, and urban cohesion. This process follows the logic of joint and systematic intervention in which public transport serves as a structuring element of the city, fostering an articulated and cohesive urban structure across different spatial scales. The reintegration of the Trambesòs tram has been one of the key structuring elements in this transformation, functioning as a connector of the urban fabric and a catalyst for new spatial and social dynamics. Therefore, as explained in Section 2, the Space Syntax analysis in UCL DepthmapX was developed to determine axial connectivity, choice (betweenness centrality), visual connectivity, and HH to analyse space and urban social dynamics [15].

The results of the spatial map analysis in UCL DepthmapX are shown in

Table 1. Space Syntax metrics summarised with UCL DepthmapX from Trambesòs area: HH, axial connectivity, choice with fewest-line map (minimal) representation, and visual connectivity.

Metrics	HH	Axial Connectivity	Choice	Visual Connectivity
Minimum	1.068	1	0	3
Maximum	4.416	44	0.452	4685
Average	2.203	7.625	0.0281	1085
Standard deviation (SD)	0.600	6.824	0.0602	916.4
Value analysed (Count)	171	171	171	27,625
Low metric	11 (<1.40)	86 (<5.3)	137 (<0.0452)	9413 (<471.2)
High metric	3 (>4.081)	37 (>2450.10)	2 (>0.407)	105 (>4216)

, where the metrics for the study area are summarised. The zone has an average integration (HH) value of 2.203, derived from 171 axes. This is a moderate integration within the urban fabric in the influence area, considering that high metrics of HH account for values higher than 4.081, and only 3 out of 171 axes have this high of a quantification. Moreover, only 11 out of 171 axes have a low HH value, which means that the closeness centrality is good in the study area. The average axial connectivity (7.625) suggests a cautious connection density with a high standard deviation (SD) and less than 1% of the axes showing high values. In this case, large metrics imply a well-connected street grid with multiple nodes and immediate spatial continuity in proximity to various urban elements associated with the transformation process of the Trambesòs line. Only two axes showed a high metric for choice, while 80% had low metrics that may have resulted from the orthogonal grid. Regarding visual connectivity, this parameter showed a similar trend to HH, with a remarkable 66% of the total spots above the low metric. The metrics summarised in Table 1 serve as references for subsequent comparisons across stations and intervention types.

In axial map analysis, integration values were used to identify the axes with the highest levels of closeness centrality within the urban fabric surrounding the Trambesòs. The map in Figure 4 represents the spatial distance of accessibility in the urban axes within the influence area. Axes in red indicate high topological accessibility, whereas blue indicates high segregation. Axial analysis revealed a hierarchical spatial distribution with the highest integration (HH) values, represented in red, identified in the Avinguda Diagonal. This axis functions as a structural backbone of the system and serves as a key mobility corridor. The Carrer Tànger/Carrer Marroc axis has a high integration (HH) value, largely because of its proximity to significant public spaces, such as the Parc Central del Poblenou and the Jardins de Miquel Martí i Pol. These adjacent open spaces enhance the topological centrality of the axis by reducing the access depth. This indicates that such spaces not only fulfil social and symbolic functions but also act as key articulating elements in the socio-spatial configuration of the area.

This axial analysis reinforces the notion that the orthogonal grid of the Eixample maintains a high degree of morphological continuity and spatial cohesion in the areas surrounding the Trambesòs corridor, even amid variations in HH values (Figure 4). A low HH is obtained in the axes within the interior blocks of the urban fabric, such as Jardins d’Irene Polo and Parc de la Ciutadella. The axes shown in blue (Figure 4), such as Carrer Wellignton, indicate low topological accessibility and a potential disconnection from the urban system surrounding the Trambesòs tram line, likely due to territorial fragmentation dynamics or the presence of urban barriers, such as the Barcelona Zoo. The differentiation and hierarchy identified through HH values allow for the inference of movement concentration patterns and the identification of areas with lower urban cohesion, providing critical insights for guiding future interventions along the Trambesòs tram system.

Axial map analysis using the choice metric represents the frequency with which each segment forms part of the shortest paths within the urban network (Figure 5). This metric identifies the axes of the urban fabric surrounding the Trambesòs tram line that are most likely to be used as part of the optimal trajectories. This indicator, associated with betweenness centrality, reveals that Avinguda Diagonal and Carrer Tànger/Carrer Marroc function as structural through-corridors within the mobility system of the Trambesòs area of influence. The highest choice values were obtained for both streets, followed by Av. Meridiana concentrates potential flow and acts as a bridge between different urban sectors. Streets with open public spaces associated with or near saturation pieces present a high value. In contrast, the lowest choice values were observed in most of the other streets around the Trambesos tram line. Calle Wellington and Rambla del Prim present low values due to the peripherical location, which indicates a reduced role within the optimal paths of the network. These differences further support the hierarchy outlined above and form the basis for the overall analysis in Section 4.2.

Axial connectivity analysis revealed a high concentration of direct connections along major axes, such as the Avinguda Diagonal (Figure 6). This is a structural corridor aligned with the Trambesòs tram, underscoring its central role in the spatial articulation of the territory. Axial connectivity represents the number of direct connections (intersections) in which each axis holds with others in the urban fabric. It is important to highlight the potential as a key urban linkage node with the highest axial connectivity values found in the Avinguda Diagonal and Avinguda Meridiana. These thoroughfares exhibit a high capacity for immediate connection with surrounding streets that position them as fundamental components of the morphological structure of the Eixample neighbourhood and as integrative corridors for both pedestrian and vehicular flows. In addition, the analysis suggests that Avinguda Diagonal and Avinguda Meridiana have been consolidated as inter-neighbourhood connectors, whereas other streets, such as Av. d’Icària and Av. Del Bogatell, with axial connectivity values of 6 and 3, correspondingly, still exhibit less permeable morphological conditions.

VGA was conducted to evaluate the visual dimension of the urban space around Trambesòs tram stations to further investigate spatial experience and perception. The visual connectivity metric represents the degree of visual connection between a point in the urban environment and its surroundings and reveals how visibility is distributed across the urban fabric. As illustrated in Figure 7, areas with a high degree of visual connectivity, such as gardens, open spaces, and squares, adjacent to Avinguda Diagonal and Plaça de les Glòries recorded high values. In contrast, areas such as streets and interior gardens registered significantly lower values, reflecting the presence of visual barriers. These results are crucial for understanding how spatial structure affects orientation, wayfinding, and pedestrian movements.

4.2. Space Syntax Metrics of the Type of Intervention Around Trambesòs: Joint Axis

The street axis analysis in

Table 2. Axial fewest-line map metrics with Space Syntax, UCL Depthmap for joint axis interventions (streets and avenues) in the Trambesòs area.

Intervention	Type of Intervention	HH (Range 1.06–4.4)	Axial Connectivity (Range 1–44)	Choice (Range 0–0.45)	Visual Connectivity (Range 3–4685)
Calle de Wellington	Joint axis	2.61	16	0.06	355–1687
Av. d’Icària	Joint axis	2.01	6	0.017	277
Av. del Bogatell	Joint axis	1.47	3	0.015	213
Av. Meridiana	Joint axis	3.37	28	0.245	1138
Av. Diagonal	Joint axis/Saturation piece	4.4	44	0.408	2059–4348
Rambla del Poblenou	Joint axis	3.28	19	0.14	308–1514
Gran Vía de les Corts Catalanes	Joint axis	3.28	18	0.06	911–1514
Rambla del Prim	Joint axis	2.45	8	0.010	717–3085

and Figure 8 reveals how certain corridors operate as key structuring elements within the Trambesòs corridor, where Avinguda Diagonal registers the highest values across the metrics. This axis excels with HH (4.4), axial connectivity (44), and choice (0.408) values that underscore their role in articulating movement and reducing fragmentation. These axes have supported connections between existing urban areas and newer centralities, e.g., Parc del Fòrum, helping to redistribute movement flows more evenly. This dominant position reflects its role as a strategic multimodal corridor and key articulator of urban flows. Avinguda Meridiana also stands out for its centrality, exhibiting high values in both choice and HH (0.245 and 3.37), confirming its function as a structural channel. Although its visual connectivity is low (1138), its role is highlighted in transverse connectivity, particularly between areas of differing urban consolidation. In contrast, Gran Via de les Corts Catalanes and Rambla del Poblenou show more moderate integration with 3.28, which indicates a primarily local function. An integrated reading of the spatial metrics reveals how the consolidation of certain articulating axes, such as Avinguda Diagonal and Avinguda Meridiana, has reinforced urban continuity in the Trambesòs corridor by connecting previously fragmented areas. As territorial structuring elements, these axes transcend neighbourhood boundaries and embed the corridor into a broader metropolitan network.

In contrast, axes, such as Avinguda de Bogatell, Avinguda d’Icària, and Carrer Wellington, show low values across all analysed metrics. This can be explained either to their peripheral location within the Trambesòs study area or to their secondary, neighbourhood-oriented nature, which positions them more as local streets than structural urban connectors.

4.3. Space Syntax Metrics of Trambesòs Tram Line

Building on the framework established in “(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” [15], this section compares the typologies of intervention presented in that work with a quantitative perspective with the spatial metrics obtained through the Space Syntax. The aim is to empirically assess how each typology has influenced accessibility and urban integration in the transformation of the area of Levante del Besòs. Spatial metrics were used to analyse accessibility patterns among tram stations and surrounding public spaces. Herein, it is described as a comparative analysis of the spatial metrics of axial analysis and VGA across tram stations in the Trambesòs corridor. For streamline interpretation, the values of axial map analysis are systematised into

Table 3. Space Syntax metrics of the axial all-line map (HH, axial connectivity, and choice) and visibility graph analysis with UCL Depthmap across tram stations on the Trambesòs tram line.

Trambesòs	HH (Range 1.9–11.8)	Axial Connectivity (Range 3–2722)	Choice (Range 0–4.46 × 10−4)	Visual Connectivity (Range 3–4685)
1 Ciutadella/Vila Olímpica	5.30	469.19	9.70 × 10−4	406
2 Wellington	5.80	470.38	1.04 × 10−3	355
3 Marina	7.32	929.33	1.64 × 10−3	1201
4 Auditori-Teatre Nacional	8.04	1016.13	1.79 × 10−3	2094
5 Glòries	8.46	1132.95	1.94 × 10−3	3921
6 Ca l‘Aranyó	8.82	1327.26	1.95 × 10−3	2188
7 Pere IV	8.50	1459.44	1.79 × 10−3	2621
8 Fluvià	7.77	1499.42	1.46 × 10−3	2439
9 Selva de Mar	7.58	1338.01	1.38 × 10−3	4315
10 El Maresme	7.25	1177.04	1.52 × 10−3	2384
11 Fòrum	7.29	1168.83	1.83 × 10−3	870

and are categorised by tram stations. Syntactic analysis reinforces the functional hierarchy illustrated in Figure 4, Figure 5 and Figure 6. Stations Glòries Ca l‘Aranyó and Pere IV are structural nodes within the system with the highest values for HH (between 8.46 and 8.82), axial connectivity (between 1132.95 and 1459.44), and choice (between 1.79 × 10⁻³ and 1.94 × 10⁻³). The visual connectivity results revealed significant differences in terms of urban legibility and spatial openness. Stations, such as Selva de Mar and Glòries, have the highest values of visual connectivity (4215 and 3921, respectively), which means that these locations are in areas with broad visual fields that enhance the orientation of users and visual accessibility, i.e., conditions often associated with adjacent parks and public spaces. For the former, Figure 9 provides a visualisation of the spatial accessibility levels for each station along the Trambesòs tram. This articulation between analytical approaches is illustrated in the synthetic map (Figure 9), which overlays key spatial metrics to identify the tram stations that function as critical nodes within the urban structure of the Trambesòs corridor, revealing substantial differences in accessibility and connectivity levels across the network. It displays that station Glòries has high scores in visual and axial connectivity and choice (normalised), indicating its role as an important node within the urban fabric.

In contrast, the stations Ciutadella/Vila Olímpica and Wellington show low values across these four metrics, HH (5.30–5.80), axial connectivity (469.19–470.38), choice (1.04 × 10⁻³ to 9.70 × 10⁻⁴), and visual connectivity (355–406), suggesting a more peripheral role in urban flow dynamics of urban barriers, such as the railway line (Figure 2A) or even the Barcelona Zoo (Figure 2B). These findings suggest that the potential perception of the urban environment plays a significant role in shaping the user experience in the vicinity of Trambesòs tram stations. Marina station shows higher values than Ciutadella/Vila Olímpica and Wellington across all dimensions, which can be attributed to its strategic location at the intersection with Avinguda Meridiana, one of the main structural corridors, as well as its proximity to Parc de l’Estació del Nord. These spatial conditions enhance both the axial and visual connectivity. Moreover, the spatial behaviour of the Auditori–Teatre Nacional and Glòries demonstrates a high visual and axial connectivity. This is likely the result of their location within an area characterised by a high concentration of cultural facilities, intermodal transport nodes, and open public spaces. Along the Avinguda Diagonal segment, all stations exhibited high integration levels, although some distinctions were detected. For instance, Selva de Mar is favoured by the open green space Parc Diagonal Mar, which enhances its visual legibility. The Fòrum station shows limited visual openness due to morphological barriers and infrastructural fragmentation. This may be a result of both its peripheral position within the study area and the morphological characteristics of the surrounding environment, which is marked by large-scale infrastructure, elevation changes, and an urban structure that is less permeable at the pedestrian scale.

4.4. Space Syntax Metrics of the Type of Interventions in Public Spaces Around Trambesòs: Punctual Interventions and Saturation Pieces

The transformation of the Levante del Besòs area has been accompanied by interventions that reclaim public spaces and promote pedestrian and cycling mobilities. This integrates the tram into a wider multimodal transport system categorised by punctual interventions and saturation pieces. Figure 10 and

Table 4. Axial all-line map metrics with Space Syntax, UCL Depthmap for urban interventions in the Trambesòs area classified by the type of punctual and saturation piece.

Intervention	Type of Intervention	HH (Range 1.9–11.8)	Axial Connectivity (Range 3–2722)	Choice (Range 0–4.46 × 10−4)	Visual Connectivity (Range 3–4685)
Parc de Carles I	Punctual	5.62	612.10	9.52 × 10−4	675
Parc de la Ciutadella	Punctual	3.81	131.89	1.59 × 10−4	1544
Parc de l’Estació del Nord	Punctual	6.29	672.40	6.30 × 10−4	2394
Auditori de Barcelona	Punctual	7.75	719.80	1.51 × 10−3	1929
Teatre Nacional de Cataluña	Punctual	6.79	597.12	3.29 × 10−3	1162
Mercat de los Encants	Punctual	7.71	864.97	1.81 × 10−3	1288
Plaça de les Glòries Catalanes	Saturation piece	7.96	982.62	1.68 × 10−3	4121
Museo del Diseño de Barcelona	Punctual	7.45	929.58	2.13 × 10−3	1547
Parc Gran Clarina	Punctual	7.46	779.21	1.41 × 10−3	1336
Parc del Clot	Punctual	5.85	314.16	6.56 × 10−4	526
Jardins de Ca l‘Aranyó	Punctual	7.04	573.58	3.39 × 10−4	505
Jardins d’Irene Polo	Punctual	4.22	100.96	1.80 × 10−4	54
Jardins d’ Ada Byron	Punctual	5.81	332.66	1.30 × 10−3	27
Parc del Centre del Poblenou	Punctual	7.18	1104.27	7.84 × 10−4	1482
Jardins de Teresa de Calcuta	Punctual	5.15	291.85	6.26 × 10−5	312
Parc Diagonal Mar	Punctual	5.15	518.16	2.65 × 10−4	2695
Parc del Fòrum	Saturation piece	5.04	133.12	1.52 × 10−4	1731

shows the visual connectivity, axial connectivity, choice, and HH for the surrounding public spaces of the Trambesòs corridor. Plaça de les Glòries Catalanes acts as a concentration node with significant values for HH (7.96), axial connectivity (982.97), visual connectivity (4121), and choice (1.68 × 10⁻³). This performance confirms its role as a central multimodal hub, although it also raises concerns over potential congestion owing to overlapping transit and pedestrian flows. Similarly, the Museu del Disseny de Barcelona shows a compelling syntactic configuration, HH (7.45), axial connectivity (929.58), and visual connectivity (1547), functioning as a redistributor of pedestrian flows. Parc de l’Estació del Nord, despite its high visual connectivity (2394), shows moderate choice (6.30 × 10⁻⁴), which suggests localised influence shaped by the surrounding built form. For instance, Parc del Centre del Poblenou demonstrates strong spatial performance, i.e., HH of 17.18 and axial connectivity of 1104.27, but low values for visual connectivity and choice (1482 and 7.84 × 10⁻⁴, respectively), confirming its role as a local structuring node. Parc Diagonal Mar presents high visual connectivity (2695), moderate HH (5.15), and choice (2.65 × 10⁻⁴), a space driven more by visual openness than structural connectivity.

In addition to being a saturation piece (Table 4), Parc del Fòrum presents an ambiguous spatial profile with low values of integration (HH) (5.04), axial connectivity (133.12), choice (2.65 × 10⁻⁴), and visual connectivity (1731). This disparity may result from both its peripheral location and spatial fragmentation caused by large-scale infrastructure, the Barcelona Convention Center, Museu Blau, and the Ronda del Litoral, which limits its integration into pedestrian and mobility networks.

Furthermore, Parc de la Ciutadella registers low HH (3.81), axial connectivity (131.89), and choice (1.59 × 10⁻⁴), likely due to spatial fragmentation from the Barcelona Zoo, the railway, and probably more connection with nearby neighbourhoods, like El Born and Arc de Triomf. These areas could benefit from complementary interventions, particularly in terms of improving the visual openness and pedestrian permeability. Punctual interventions (Table 4), such as Parc Carles I and Jardins de Ada Byron, presented significantly lower values of HH (5.62–5.81), axial connectivity (612.10–332.66), and choice (9.52 × 10⁻⁴–1.30 × 10⁻³), which indicate a more local and fragmented role within the urban fabric. This is consistent with their function as public spaces, which is primarily intended for leisure and passive use. In visual connectivity, the low values for spaces, such as the Jardins d’Irene Polo (54) or Jardins d’Ada Byron (27), describe a more enclosed spatial configuration.

Parks, plazas, and strategically located public facilities have played a key role in activating public space and improving local connectivity along the Trambesòs corridor. These public spaces serve not only as gathering places but also as new pedestrian attractions that reflect increased spatial accessibility.

5. Discussion

The qualitative analysis developed by Reyes et al. [15] provided valuable insights into how residents perceive the tram and public spaces as agents of urban transformation in the Levante del Besòs area. Building on this foundation, the incorporation of quantitative spatial analysis through Space Syntax methodology has complemented and empirically validated these perceptions, offering measurable evidence on patterns of accessibility, connectivity, and cohesion. However, while this spatial reading confirms the structural role of the tram within the urban fabric, it does so from a static and cross-sectional perspective, which limits its ability to capture the temporal evolution of these dynamics. This spatial reading allows for the assessment of current accessibility levels to key urban nodes, such as public spaces and facilities, which highlights the structuring role of the Trambesòs tram within the broader territorial reconfiguration.

The alignment between qualitative findings and spatial metrics strengthens the reliability of the results and contributes to a more comprehensive understanding of the spatial and social impact of trams in Barcelona. This methodological articulation reinforces the empirical validation of the morphological logic proposed in the previous study and allows for a partial validation of the internal intervention logic as a physical, functional, spatial, and morphological strategy that can serve as a structural foundation for urban regeneration processes. Through configurational analysis, spatial patterns were identified that partially support the functional coherence of the three intervention typologies and reveal the potential emergence of new urban centralities. However, this validation remains preliminary and could be complemented by longitudinal and comparative studies with other urban areas or cities, incorporating the temporal dimension, or with user behaviour.

The overall Space Syntax analysis suggests that the study area has a role in the urban fabric with deeply uneven values, highlighting both challenges and opportunities. The average axial connectivity (7.625) indicates that most streets offer local reach. A few avenues truly function as structural spines as it is reinforced by the choice values, i.e., 80% of segments have little contribution to through-movement. This is graphically depicted in Figure 5, where deep blue lines are shown across the study area and a few of them are in red. Meanwhile, integration shows many spots in yellow (Figure 4), and axial connectivity has many lines with moderate values and a few with low metrics (Figure 6). All of these allow to conclude that movement flows will concentrate along few corridors but disperse toward many moderately integrated destinations that are axially connected. In practical terms, this means that while a small number of main streets are linked to carry the bulk of pedestrians and transit traffic, the rest of the network likely remains as destinations with local functioning. The VGA analysis across the study area reveals a well-distributed pattern (Figure 7), with multiple zones demonstrating moderate to high levels of visibility. This distribution does not strictly align with the central axis or traditional urban cores, indicating that visual connectivity is not solely determined by spatial centrality. Overall, distribution of the metrics across the targeted interventions (Figure 8, Figure 9 and Figure 10) show that they are a result of their urban nature (punctual interventions, articulation axes, and saturation pieces) that have enhanced permeability and openness in various parts of the urban fabric and are not mainly determined by spatial centrality.

The axial map analysis for the Joint Axis interventions show that Avinguda Diagonal and Avinguda Meridiana are key segments for integration, connectivity, and centrality. Meanwhile, they have, together with Rambla del Poblenou and Rambla del Prim, remarkable choice and visual connectivity metrics.

Open spaces have generated new urban flows with high local accessibility values and pedestrian movement. This suggests that the combination of intervention typologies have been key to consolidating the morphological structure surrounding the Trambesòs, enhancing cross-connectivity and supporting new urban centralities. These Punctual Interventions and Saturation Pieces enhance local accessibility and urban experience, although their influence on the broader network depends on morphological integration.

In regard of relevant public spaces, those located over the Avinguda Diagonal, Avinguda Meridiana, and open spaces present high metrics in terms of axial and visual connections (e.g., Plaça de les Glòries Catalanes, Parc de l’Estació del Nord, Parc Diagonal Mar). Nevertheless, places with low metrics (e.g., Jardins d’Irene Polo, Parc del Clot, and Jardins de Teresa de Calcuta) are near the Avinguda Diagonal, which is a well-integrated segment. Meanwhile, the VGA describes those peripheral spots in the study area, e.g., Parc de Diagonal Mar and Parc de l’Estació Nord, as having significant visual connectivity, which positively affects social interaction, orientation, wayfinding, and leisure. Additionally, the VGA endorses the results of the axial map analysis, as better results are presented for places compared to Avinguda Diagonal and Avinguda Meridiana.

From the perspective of urban cohesion, the tram system has contributed to the articulation of sectors with diverse socioeconomic dynamics, thus facilitating a more equitable distribution of mobility and access to services. The evaluation of intermodal nodes shows that public spaces, such as Plaça de les Glòries and Selva de Mar, have acquired a structural role that enables the convergence of multiple transport modes and consolidates their status as strategic points of connectivity. However, the emergence of certain spaces as intermodal hubs has also led to flow concentration, which, in some cases, may exceed the carrying capacity of adjacent public spaces, prompting the need for redistribution strategies and measures to mitigate saturation. In addition, tram-adjacent areas display positive levels of social interaction and access to services that show average pedestrian accessibility within a 6-min walk (500 m) from most tram stations.

The analysis of the stations shows that axial metrics have high values for almost all stations, except Ciutadella/Vila Olímpica and Wellington. These two stations have a physical barrier from the Barcelona Zoo and the Barcelona railway, which also affects their visual connectivity. Likewise, Fòrum is well connected in terms of axial metrics, but it has a low magnitude for its visibility. This is explained by its location over Avinguda d’Eduard Maristany, near its interception with the Avinguda Diagonal and its surrounding urban buildings.

The application of Space Syntax metrics to the analysis of the Trambesòs corridor validates and refines the spatial logic behind the three typologies of intervention, Punctual Interventions, Articulation Axes, and Saturation Pieces, by revealing distinct patterns in the spatial behaviour of public spaces, tram stations, and main streets. Through the combined reading of choice, integration, axial connectivity, and visual connectivity, it becomes evident that each type of intervention interacts differently with the underlying spatial configuration of the city.

The syntax analysis identifies critical nodes with potentially high pedestrian flow, particularly around major intersections and intermodal transfer points, i.e., Plaça de les Glòries Catalanes. High-traffic zones require targeted interventions to manage movement, mitigate potential congestion, and redistribute flows to underutilised areas. Conversely, some peripheral zones remain with a lower probability of pedestrian activity, i.e., Parc Carles I. This finding highlights the need for complementary strategies that promote equity in mobility and a more balanced territorial structure.

Despite the findings, it is important to acknowledge the methodological boundaries that circumscribe the scope of this study. First, spatial metrics derived from Space Syntax, such as integration (HH), choice, axial connectivity, and visual connectivity, offer a static reading of urban configuration. Although this study relies on a static morphological syntax metric, thereby not capturing temporal variations, such as land-use changes, hourly flows, seasonal dynamics, or the evolution of each intervention, it establishes a cross-sectional baseline for future inquiry. Subsequent longitudinal research could build on this foundation by measuring syntactic accessibility at multiple time points before and after interventions, enabling direct causal attribution to observe changes. Adopting a dynamic approach is expected to yield a more compressive insight into the temporal dynamics of urban regeneration processes. Nevertheless, the configurational indices obtained, such as the high values of integration and connectivity in key nodes, like Glòries, Ca l’Aranyó, or Avinguda Diagonal, reflect favourable spatial patterns that support the hypothesis that the articulation between transport, public space, and urban morphology has contributed to improved accessibility and territorial cohesion in the study area.

However, it is important to note that the scope of this study was methodologically delimited to spatial and morphological variables derived from a configurational perspective. While factors such as socioeconomic conditions, demographic characteristics, and the dynamics of multimodal transport systems are critical for understanding urban regeneration in a holistic manner, they have not been incorporated into this research. This exclusion is not a limitation of oversight but rather a deliberate methodological decision to isolate and assess the spatial logic of intervention. This study aims to establish a design-oriented framework based on spatial metrics, which can later be complemented by interdisciplinary analyses that integrate the social and functional dimensions of urban transformation.

Furthermore, the results show that certain metrics, such as choice, exhibit low variability (with 80% of segments scoring low), which may be influenced by the orthogonal structure of the Eixample. This highly permeable and regular grid tends to dominate configurational metrics, potentially masking the specific effects of some interventions. For example, Avinguda Diagonal and Avinguda Meridiana concentrate the highest values of integration and connectivity, which may reflect the structural logic of the urban fabric more than the direct impact of the tram. However, it is important to emphasise that the tram does not operate in isolation but as part of a broader internal transformation strategy that articulates punctual interventions, articulation axes, and saturation pieces. Therefore, the observed effects should be understood as the result of a systemic interaction between transport infrastructure, public space, and urban morphology.

Consequently, future research should incorporate multitemporal or longitudinal analyses to contrast and enrich the configurational findings. This would allow for a more comprehensive evaluation of urban regeneration processes and better identification of the specific effects of each type of intervention. It is worth noting that this study builds upon a qualitative foundation developed in a previous study [15], which characterises the regeneration process through everyday experience, spatial perception, and social articulation. Therefore, the integration of temporal approaches and dynamic data would broaden the understanding of the processes analysed and strengthen the validity of the results from a configurational perspective.

It is of great importance to note that the study area by a 500 m-radius around each tram station produces morphological metrics that reflect walkability around each tram stop. It should be noted, however, that increasing the radius around each station would bring major thoroughfares and intermodal links into the analysis, shifting the emphasis from purely pedestrian paths to a blended pedestrian–vehicular network. Therefore, this definition has an influence on the axial and visual metrics obtained herein, as a broader area consideration would result in different magnitudes in these parameters. In such broader catchments, average integration (HH) and choice values would rise as high-capacity corridors dominate shortest-path computations. Axial connectivity would increase with the greater number of direct intersections among primary arteries. Visual connectivity patterns would describe some increases, since wide avenues and open plazas offer more uniform sightlines than narrow streets. These scale-dependent transformations underscore the dual role of the tram, locally enhancing pedestrian permeability, while at broader scales, integrating with and bolstering the existing road network. The delimitation of the study area around main transport corridors allows us to understand its functionality and usefulness. Therefore, the scope of this study is to provide a realistic approach to the morphology of urban environments.

Quantitative evidence confirms the core premise of earlier qualitative research: that public transport and public space function as co-catalysts in urban regeneration. The tram had enhanced accessibility throughout the corridor, particularly within the most integrated segments of the street network. New urban centralities have emerged at key intersections, enabling a more equitable redistribution of flow and supporting the emergence of multifunctional urban nodes. These transformations have also reinforced inter-neighbourhood connections, which promote cohesion and reduce longstanding spatial barriers. However, disparities in accessibility persist in several peripheral areas that continue to display low integration and connectivity values. Addressing these gaps requires targeted interventions to ensure that the benefits of regeneration and sustainable mobility are shared more equitably across the urban fabric.

6. Conclusions

This configurational analysis using Space Syntax empirically demonstrated how the Trambesòs line functions as a structuring pivot in Levante del Besòs, Barcelona. The tramway, in association with a network of public spaces and urban facilities, including Plaça de les Glòries Catalanes, Parc del Centre del Poblenou, Parc de l’Estació del Nord, Parc Diagonal Mar, and the Museu del Disseny de Barcelona, has operated as a physical and spatial backbone that supports the transformation of a previously fragmented area into a more cohesive and accessible urban fabric. This systemic articulation has not only improved spatial integration, as evidenced by high integration (HH = 4.4), axial connectivity (44), and choice (0.408) values in the Avinguda Diagonal but also in less expected corridors, such as Carrer Tànger/Carrer Marroc and Rambla del Poblenou, which recorded significant values due to their proximity to key public spaces and their role in connecting emerging centralities.

The findings validate the morphological logic proposed in the previous qualitative study, confirming that the three types of intervention, punctual interventions, articulation axes, and saturation pieces, are not only spatially coherent but also functionally effective for enhancing accessibility and cohesion. For example, Plaça de les Glòries and Parc del Fòrum, as saturation pieces, exhibit high visual connectivity (4121 and 1731, respectively), whereas punctual interventions, such as the Museu del Disseny and Mercat dels Encants show strong axial integration (HH = 7.45 and 7.71), reinforcing their role as redistributors of pedestrian flows, which demonstrates how each type contributes to flow redistribution and the consolidation of new centralities. The results suggest that physical and morphological interventions, when conceived as part of systemic and multiscale logic, can serve as a structuring foundation for more inclusive and sustainable urban transformations.

Space Syntax analysis also revealed a heterogeneous yet strategically structured network, with an average HH value of 2.203 and a high standard deviation in axial connectivity (SD = 6.824), allowing for the coexistence of local specificities within a unified urban structure that is connected at the metropolitan scale. This finding reinforces the idea that physical and morphological coherence can serve as a foundation for addressing broader urban challenges.

Moreover, triangulation between qualitative and quantitative approaches enabled the identification of new spatial dynamics, such as the emergence of secondary centralities and transversal pedestrian flows, which were not initially captured. These findings highlight the potential of this logic to adapt through microscale interventions and new articulation axes, especially in areas with low integration or visual fragmentation, and they can be further validated through pedestrian mobility data to closely observe if behaviours align with the movement patterns predicted by the syntax analyse.

This study confirms that public transport and public spaces, when articulated through systemic morphological logic, can act as co-catalysts in sustainable urban regeneration processes. The configurational methodology employed provides a replicable and adaptable framework for evaluating the spatial impact of physical interventions and validating the internal coherence of multiscale intervention strategies through spatial metrics. Future research should expand the scope of the analysis to broader urban scales and incorporate socioeconomic variables to support a more comprehensive understanding of regeneration dynamics.

Based on the results and boundaries discussed, the internal intervention logic, structured around punctual interventions, articulation axes, and saturation pieces, can be reinforced through urban planning strategies aligned with spatial patterns identified via configurational analysis. This includes strengthening secondary corridors with low integration and consolidating emerging centralities through coordinated spatial interventions. Intermodal nodes of different scale and orientation, such as Glòries and Selva de Mar, require integrated governance frameworks that embed them within a systemic accessibility network capable of balancing spatial and functional hierarchies across territorial levels. This articulation can be supported through decentralised mobility nodes and adaptive public space design. In this context, it is essential to advance toward a polysemic and polycentric urban structure where access is managed equitably and efficiently. These orientations validate the proposed morphological logic and provide an operational foundation to guide urban regeneration strategies that are flexible and context sensitive in response to evolving territorial dynamics. Within this framework, the tram assumes a strategic role as an infrastructure supporting integrated public policy, enabling the articulation of multiscale interventions and reinforcing territorial cohesion through spatially informed planning.