Inspired by postcolonial critiques, urban studies today is characterized by conceptual and methodological experimentation in pursuit of a more global approach to understanding cities. The challenge is to develop methods and theoretical practices which allow conceptual innovation to emerge from any urban situation or urbanization process, sustaining wider conversations while insisting that concepts are open to revision. This maps well on to the core methodological problematic of comparison. Mindful of the strong limits to comparison presented by conventional quasi-scientific methods, this paper sets out the basis for a reformatted comparative method. A new grounding for comparison is proposed, specific to the field of the urban, and a new typology of tactics for undertaking urban comparative research is suggested. The paper weaves together classic approaches and more recent innovations in comparison from within urban studies with a wider philosophical analysis of the issues at stake in reframing the architecture of comparison. The paper stands as an invitation to practise global urban studies differently – comparatively – but also to practise comparison differently, in a way that opens urban studies to a more global repertoire of potential insights. The paper develops this invitation and methodological quest through Marxist political-economy; through actually-existing vernacular comparative practices of urban studies; and through insights gleaned from Gilles Deleuze’s philosophical project. The last section of the paper explains how this new vocabulary of comparative method can be put to work through a review of some recent experiments in the field of global urban studies.
With urban population increasing dramatically worldwide, cities are playing an increasingly critical role in human societies and the sustainability of the planet. An obstacle to effective policy is the lack of meaningful urban metrics based on a quantitative understanding of cities. Typically, linear per capita indicators are used to characterize and rank cities. However, these implicitly ignore the fundamental role of nonlinear agglomeration integral to the life history of cities. As such, per capita indicators conflate general nonlinear effects, common to all cities, with local dynamics, specific to each city, failing to provide direct measures of the impact of local events and policy. Agglomeration nonlinearities are explicitly manifested by the superlinear power law scaling of most urban socioeconomic indicators with population size, all with similar exponents (1.15). As a result larger cities are disproportionally the centers of innovation, wealth and crime, all to approximately the same degree. We use these general urban laws to develop new urban metrics that disentangle dynamics at different scales and provide true measures of local urban performance. New rankings of cities and a novel and simpler perspective on urban systems emerge. We find that local urban dynamics display long-term memory, so cities under or outperforming their size expectation maintain such (dis)advantage for decades. Spatiotemporal correlation analyses reveal a novel functional taxonomy of U.S. metropolitan areas that is generally not organized geographically but based instead on common local economic models, innovation strategies and patterns of crime.
Abstract Cross-camera vehicle trajectory reconstruction is essential for roadside perception systems supporting traffic analysis, safety evaluation, and infrastructure monitoring. In practical deployments, roadside cameras often exhibit partial or minimal overlaps, providing limited spatiotemporal continuity and making cross-camera association challenging. This paper proposes a global trajectory reconstruction framework designed for such roadside surveillance networks. Single-camera trajectories are first extracted and projected into a unified road-plane coordinate system through calibration, enabling metric-level comparison across views. Appearance features and motion cues are then jointly exploited in a multi-stage association strategy that integrates spatiotemporal feasibility and visual similarity. Matched trajectories are stitched and refined using quality-aware alignment and short-gap compensation to generate continuous and physically plausible cross-camera trajectories. Real-world experiments with roadside cameras, RTK-equipped vehicles, and UAV-based trajectory data demonstrate that the proposed method achieves high association accuracy and reconstruction precision in both single- and multi-vehicle scenarios while maintaining low computational overhead.
Urban scaling laws describe how an urban quantity $Y$ varies with city population $P$, typically as $Y \sim P^β$. These relations are usually obtained from cross-sectional comparisons across cities at a given time (transversal scaling), but their link to the temporal evolution of individual cities (longitudinal scaling) remains unclear. Here we derive explicit expressions for the transversal exponent from the longitudinal dynamics of cities. We show that the measured exponent does not directly reflect individual city dynamics, but instead arises from a snapshot of a heterogeneous ensemble of cities with distinct growth trajectories. As a result, transversal scaling combines intrinsic dynamics with statistical effects due to the distribution of city sizes and correlations between population and city-specific parameters. Consequently, cross-sectional scaling laws cannot, in general, be used to infer the dynamics of individual cities. In particular, apparent sub- or superlinear scaling can emerge even when all cities follow linear longitudinal dynamics, as we demonstrate for the area-population relation. Strikingly, the behavior associated with the transversal exponent is in general not observed in the trajectory of any individual city, underscoring its collective, rather than dynamical, nature. More broadly, the transversal exponent has a clear dynamical meaning only under restrictive conditions-when cities behave as scaled versions of one another and path dependence is weak. Outside of these limits, it is not a law of urban growth, but a statistical artefact of heterogeneity.
The article aims to determine the preferences of Polish consumers in the use of the subscription model in their leisure time behaviors, taking into account the size of their place of residence. The study employed a diagnostic survey method and statistical analysis as the research approach. The authors' research has shown great interest in the subscription model among Polish respondents in behaviors related to spending leisure time; however, no significant differences were observed between the studied groups based on place of residence, indicating a consistent pattern of consumer preferences among respondents from both urban and rural environments. The main areas of interest turned out to be primarily VoD platforms and music streaming, and the most important factor influencing consumer behavior in the context of subscription services is the economic factor, mainly the price of the subscription...n.
The undirected edge geography is a two-player combinatorial game on an undirected rooted graph. The players alternatively perform a move consisting of choosing an edge incident to the root vertex, removing the chosen edge, and marking the other endpoint as a new root vertex. The first player who cannot perform a move is the loser. In this paper, we are interested in the undirected edge geography game on the grid graph $P_m\square P_n$. We completely determine whether the root vertex is a winning position (N-position) or a losing position (P-position). Moreover, we give a winning strategy for the winner.
Commuting Origin-Destination (OD) flows capture movements of people from residences to workplaces, representing the predominant form of intra-city mobility and serving as a critical reference for understanding urban dynamics and supporting sustainable policies. However, acquiring such data requires costly, time-consuming censuses. In this study, we introduce a commuting OD flow dataset for cities around the world, spanning 6 continents, 179 countries, and 1,625 cities, providing unprecedented coverage of dynamics under diverse urban environments. Specifically, we collected fine-grained demographic data, satellite imagery, and points of interest~(POIs) for each city as foundational inputs to characterize the functional roles of urban regions. Leveraging these, a deep generative model is employed to capture the complex relationships between urban geospatial features and human mobility, enabling the generation of commuting OD flows between urban regions. Comprehensively, validation shows that the spatial distributions of the generated flows closely align with real-world observations. We believe this dataset offers a valuable resource for advancing sustainable urban development research in urban science, data science, transportation engineering, and related fields.
Understanding urban form is crucial for sustainable urban planning and enhancing quality of life. This study presents a data-driven framework to systematically identify and compare urban typologies across geographically and culturally distinct cities. Using open-source geospatial data from OpenStreetMap, we extracted multidimensional features related to topography, multimodality, green spaces, and points of interest for the cities of Lausanne, Switzerland, and Philadelphia, USA. A grid-based approach was used to divide each city into Basic Spatial Units (BSU), and Gaussian Mixture Models (GMM) were applied to cluster BSUs based on their urban characteristics. The results reveal coherent and interpretable urban typologies within each city, with some cluster types emerging across both cities despite their differences in scale, density, and cultural context. Comparative analysis showed that adapting the grid size to each city's morphology improves the detection of shared typologies. Simplified clustering based solely on network degree centrality further demonstrated that meaningful structural patterns can be captured even with minimal feature sets. Our findings suggest the presence of functionally convergent urban forms across continents and highlight the importance of spatial scale in cross-city comparisons. The framework offers a scalable and transferable approach for urban analysis, providing valuable insights for planners and policymakers aiming to enhance walkability, accessibility, and well-being. Limitations related to data completeness and feature selection are discussed, and directions for future work -- including the integration of additional data sources and human-centered validation -- are proposed.
The emergence of geographical ‘big data’ provides new opportunities for studying urban issues. This study uses geographical ‘big data’ on point of interest density (POID), degree of urban function mixing (MIX), location check-in density (CIQD), housing prices (HP), and population change (POPC) to measure the urban vitality of patches of new development that occurred in Chinese cities from 2005 to 2015. The study uses association rule analysis to explore the relationship between different urban growth patterns on urban vitality, and the results indicate that different forms of urban growth have different effects on urban vitality. Infilling is characterized by high values for point of interest density and location check-in density with low values for urban function mixing and mixed values for population change. Edge-expansion is associated with high values for population change and urban function mixtures. Outlying expansion is associated with several negative values for urban vitality, particularly variables related to interactions between people and the environment around them (CIQD). The results indicate that cities may utilize these different forms of urban growth patterns to achieve different goals; for example, infilling may be more effective for office-style development in areas with existing higher population density and urban function mixtures, and edge-expansion may be effective for rapidly absorbing large populations and hosting urban functions that require larger footprints. As such, Chinese cities currently undergoing early stages of development should pursue high-intensity edge-expansion development. To the best of the authors’ knowledge, this is the first attempt to study the relationship between urban expansion types and urban vitality through the use of ‘big data,’ and the results of this study can provide guidance on urban spatial development for government leaders and researchers in the future.
Abstract The combined trends of urban heat island intensification and global warming are focusing attention on greening of cities as a tool for urban heat mitigation. Our study examines the range of research approaches and findings regarding the role of urban green infrastructure (UGI) in mitigating urban heat and enhancing human comfort. It provides an overview based on 89 studies, carried out in a range of geographic and climatic regions. We surveyed the distribution of methodologies employed, spatio-temporal scales considered, type and extent of UGI, climatic variables studied and contribution of UGI to ambient air cooling and enhancement of human comfort. It was found that neither the differences in geographic location or in climate conditions had a significant impact on the choice of research approach. The studies, mostly done on limited spatio-temporal scales, have focused on the rate of air cooling by UGI, and to a lesser extent on its impact on thermal comfort. Maximum observed intensities of park cool island (PCI) effects typically ranged between 1.5 °C–3.5 °C, with no apparent correlation to climatic region. However, there is a tendency seen for larger green sites to induce a stronger PCI, whereas well-shading street trees also have a significant cooling and relieving effect.
Helena Pueres Roldão, Eduardo Augusto Werneck Ribeiro, Mario Francisco Leal de Quadro
Este artigo discute o uso de imagens térmicas e mapas de uso do solo para combater ilhas de calor e promover um ambiente urbano sustentável em cidades pequenas, usando São Francisco do Sul, Brasil, como estudo de caso. Os resultados mostram diferenças de aquecimento em diferentes partes da cidade, sublinhando a necessidade de considerar o clima no planejamento urbano para promover a sustentabilidade e minimizar o desconforto térmico. O estudo sugere que estes princípios podem guiar o licenciamento ambiental para reduzir áreas impermeabilizadas e evitar o surgimento de ilhas de calor.
Positive developmental consequences for home-based enterprises (HBEs) are diminished in South African townships, due to insufficient alignment of business support interventions (BSI). There is limited urban planning knowledge on how HBEs in townships operate within residential zones and how spatial and regulatory challenges affect their development. The integration of supporting informal businesses presents a challenge since the informal economy does not have detailed spatial information. This article aims to address gaps in urban planning knowledge regarding how HBEs operate in residential zones, particularly in areas known for historical land-use conflicts. A case study approach with mixed methods (surveys and interviews) is used to investigate local initiatives for economic development in a ward area, using quantitative and qualitative data to better understand the interdisciplinary linkages of urban development in the South Durban Basin of eThekwini Municipality. Findings show that there are gaps in the way in which HBEs understand planning, policy, and regulations and this needs to be considered in reducing the lack of business support interventions for local economic development.
Cities. Urban geography, Urban groups. The city. Urban sociology
Violence is commonly linked with large urban areas, and as a social phenomenon, it is presumed to scale super-linearly with population size. This study explores the hypothesis that smaller, isolated cities in Africa may experience a heightened intensity of violence against civilians. It aims to investigate the correlation between the risk of experiencing violence with a city's size and its geographical isolation. Over a 20-year period, the incidence of civilian casualties has been analysed to assess lethality in relation to varying degrees of isolation and city sizes. African cities are categorised by isolation (number of highway connections) and centrality (the estimated frequency of journeys). Findings suggest that violence against civilians exhibits a sub-linear pattern, with larger cities witnessing fewer casualties per 100,000 inhabitants. Remarkably, individuals in isolated cities face a quadrupled risk of a casualty compared to those in more connected cities.