The `15-minute city' has emerged as a central paradigm in urban planning, promoting universal access to work and essential services within short travel times. Its feasibility-particularly for commuting to work-has however rarely been examined quantitatively. Here, we show that proximity to employment is fundamentally constrained by the internal structure of urban economies. Combining urban geometry with empirically observed firm-size distributions, we derive a lower bound on commuting times that holds independently of planning choices or transport technologies. This bound reveals a sharp transition: when employment is sufficiently concentrated, no spatial rearrangement of workplaces can ensure uniformly short commutes, even under optimal placement. Applied to Paris and its near suburbs, we find that achieving universal 15-minute commutes would require substantial economic restructuring or differentiated mobility strategies. The relevant question is therefore not whether an $x$-minute city is achievable, but what the minimal feasible $x$ is given a city's economic structure and spatial scale.
The automated generation of interactive 3D cities is a critical challenge with broad applications in autonomous driving, virtual reality, and embodied intelligence. While recent advances in generative models and procedural techniques have improved the realism of city generation, existing methods often struggle with high-fidelity asset creation, controllability, and manipulation. In this work, we introduce CityGenAgent, a natural language-driven framework for hierarchical procedural generation of high-quality 3D cities. Our approach decomposes city generation into two interpretable components, Block Program and Building Program. To ensure structural correctness and semantic alignment, we adopt a two-stage learning strategy: (1) Supervised Fine-Tuning (SFT). We train BlockGen and BuildingGen to generate valid programs that adhere to schema constraints, including non-self-intersecting polygons and complete fields; (2) Reinforcement Learning (RL). We design Spatial Alignment Reward to enhance spatial reasoning ability and Visual Consistency Reward to bridge the gap between textual descriptions and the visual modality. Benefiting from the programs and the models' generalization, CityGenAgent supports natural language editing and manipulation. Comprehensive evaluations demonstrate superior semantic alignment, visual quality, and controllability compared to existing methods, establishing a robust foundation for scalable 3D city generation.
Abstract Path planning is a fundamental component in the development of robotics, autonomous navigation, and intelligent systems, playing a pivotal role in the functioning of smart cities. Within the realm of smart cities, where infrastructure is becoming increasingly interconnected, efficient path planning algorithms are essential for optimizing traffic flow, reducing congestion, and ensuring the seamless movement of people and goods. Among various path planning algorithms, the A* algorithm remains one of the most widely used approaches due to its completeness and optimality under consistent heuristics. However, traditional A* suffers from several limitations when applied to complex 3D environments, including uniform neighbor expansion, fixed-resolution grids, and overly simplistic heuristic functions. These drawbacks often lead to excessive computation, suboptimal paths, and failure in cluttered or large-scale scenarios. To address these challenges, we propose a direction aware and self-adaptive A* algorithm named DASA*, an enhanced A* based path planning framework. Firstly, we propose an adaptive hierarchical direction-aware neighborhood selection mechanism. Driven by a lightweight stagnation detector based on open-set growth rate, this mechanism enables seamless automatic switching of neighborhood expansion from narrow conical angles to full 26-neighbourhood coverage. This fundamentally resolves the search incompleteness inherent in traditional fixed-conical-angle directional A* algorithms at the mechanism level, significantly enhancing planning success rates and efficiency. Secondly, a resolution-adaptive search strategy dynamically adjusts planning granularity based on local obstacle density. It advances rapidly with coarse granularity in sparse areas while switching to fine granularity for precise obstacle avoidance in dense zones, achieving an optimal balance between efficiency and safety in heterogeneous environments. Moreover, the designed learnable heuristic plugin interface enables seamless integration of PPO models trained on spatio-semantic features. This provides more informative, purposeful, and forward-looking heuristic guidance, further accelerating convergence towards optimal paths. Finally, we have devised a delayed path adjustment strategy that simplifies trajectories by omitting redundant waypoints through a deferred update mechanism. Subsequently, cubic B-spline interpolation is applied to smooth the path, ensuring curvature continuity and effectively preventing abrupt turns and unnatural maneuvers. This enhances both the fluidity and kinematic plausibility of the trajectory. Subsequently, Extensive experiments in simulated 3D environments demonstrate that DASA* outperforms conventional A* and Other mainstream algorithms in terms of planning time, length of optimal path, and success rate. The proposed framework provides a practical and extensible foundation for real-world applications such as UAV navigation, mobile robotics, and autonomous inspection in complex terrains.
This article examines the responses elicited by experiments addressing complex issues in housing. It explores how such experiments are implemented and their ability to facilitate or hinder dialogue beyond their initiators, decision-makers, and urban and real estate development professionals. The first theoretical part looks at the various definitions and typologies of urban experimentation, which reveal seemingly contradictory aspects regarding their implementation, resulting in an analytical grid. We then apply this grid to three housing development projects: two experiments on the energy transition and the third on metropolitan hospitality. This enables us to observe how these experiments are positioned between contradictory dynamics regarding their implementation, objectives and the actors involved. Our findings indicate that, while the creation of support and the enrollment of new participants are the most sought-after tools for addressing dissent in the cases studied, the processes for forming alliances diverge. Our perspective finally helps us understand the specific features of experiments conducted in housing projects that also aim to transform living practices.
Aesthetics of cities. City planning and beautifying, Urban groups. The city. Urban sociology
Traditional villages face many difficulties in the era of globalization, especially in light of fast industrialization and urbanization. The breakdown of settlement patterns and the erosion of local characteristics and cultural identities pose critical issues for the sustainable development of these communities. While research on traditional villages and dwellings in core cultural areas is relatively advanced, there remains a significant gap in studies focusing on traditional villages and dwellings in multicultural intermingling regions. By clarifying the characteristics of traditional villages and the cultural landscapes of dwellings under the influence of multiple cultures, as well as their differentiation and underlying mechanisms, this research aims to provide theoretical support for the protective planning of world cultural heritage, which is increasingly characterized by clustering and regionalization. Taking the traditional villages and dwellings in the Jiangxi and Anhui junction area as a case study, we developed a cultural landscape factor system for traditional villages and dwellings across four dimensions: natural environment, spatial configuration, dwelling typology, and historical and cultural context. Using geographic information systems (GIS) zoning methods and statistical spatial analysis, we divided the area into three distinct cultural landscape zones. The findings indicate that the cultural landscapes within each zone exhibit unique regional characteristics at both the village and dwelling levels, particularly in site selection, settlement patterns, and architectural aesthetics. Differentiation across zones is shaped by natural factors, such as topography and water systems, as well as by regional culture, historical migration, the chronological sequence of regional development, commerce and trade growth, and the evolution of administrative systems, alongside broader cultural, economic, and social factors, showing consistent patterns. This study demonstrates that utilizing a scientific and objective zoning approach to accurately identify the cultural landscape characteristics and differentiation patterns across various cultural zones, while clarifying the historical evolution of villages and the transformation of dwelling forms, provides practical insights for cultural landscape zoning in other multicultural regions. Furthermore, it provides scientific guidance to advance China’s rural revitalization strategy and supports the regional protection and sustainable development of world cultural heritage.
Abstract Urban planning is challenging especially rapidly developing areas, making it imperative for decision-makers to be transparent, fair, and data-driven. This study looks at how planning decisions are made in local government in Australia. It compares two cases in Wyndham City where communities asked for the creation of new suburbs. The research uses evidence from council records and voting outcomes. It shows how one vote changed the final decision in both cases. In one case, a vote went against what the community wanted. This finding shows how personal bias and poor judgment can appear in traditional systems of governance. The study finds that technology-assisted decision-making (TADM) can improve openness, fairness, and accountability. The use of new technologies can make decision-making more consistent and more based on evidence. It can also help reflect public views more accurately. The study concludes that TADM should become part of urban governance. It recommends more research and real-world testing to build systems that support fair and sustainable planning outcomes.
Cities. Urban geography, Urban groups. The city. Urban sociology
Understanding and predicting Origin-Destination (OD) flows is crucial for urban planning and transportation management. Traditional OD prediction models, while effective within single cities, often face limitations when applied across different cities due to varied traffic conditions, urban layouts, and socio-economic factors. In this paper, by employing Large Language Models (LLMs), we introduce a new method for cross-city OD flow prediction. Our approach leverages the advanced semantic understanding and contextual learning capabilities of LLMs to bridge the gap between cities with different characteristics, providing a robust and adaptable solution for accurate OD flow prediction that can be transferred from one city to another. Our novel framework involves four major components: collecting OD training datasets from a source city, instruction-tuning the LLMs, predicting destination POIs in a target city, and identifying the locations that best match the predicted destination POIs. We introduce a new loss function that integrates POI semantics and trip distance during training. By extracting high-quality semantic features from human mobility and POI data, the model understands spatial and functional relationships within urban spaces and captures interactions between individuals and various POIs. Extensive experimental results demonstrate the superiority of our approach over the state-of-the-art learning-based methods in cross-city OD flow prediction.
Georgios Mylonas, Athanasios Kalogeras, Sobah Abbas Petersen
et al.
Smart cities have been a very active research area in the past 20 years, while continuously adapting to new technological advancements and keeping up with the times regarding sustainability and climate change. In this context, there have been numerous proposals to expand the scope of smart cities, focusing on resilience and sustainability, among other aspects, resulting in terms like smart sustainable cities. At the same time, there is an ongoing discussion regarding the degree in which smart cities put people at their centre. In this work, we argue toward expanding the current smart city definition by integrating the circular economy as one of its central pillars and adopting the term smart (and) circular city. We discuss the ways a smart and circular city encompasses both sustainability and smartness in an integral manner, while also being well-positioned to foster novel business activity and models and helping to place citizens at the heart of the smart city. In this sense, we also argue that previous research in smart cities and technologies, such as those related to Industry 4.0, can serve as a cornerstone to implement circular economy activities within cities, at a scale that exceeds current activities that are based on more conventional approaches. We also outline current open challenges in this domain and research questions that still need to be addressed.
This study was conducted in Bandung, the provincial capital of West Java, to reevaluate the tactile paving installation system based on the movement patterns of visually impaired pedestrians in urban networks. Given the rising global prevalence of low vision and blindness, creating inclusive urban environments has become a critical health and social issue. The research aimed to address the gap in accessibility by focusing on how tactile paving can better align with the daily rhythms and needs of visually impaired individuals. Data collection involved interviews, and data analysis utilized a mixed-methods approach. Findings revealed that the movement patterns of visually impaired pedestrians are intricately connected to their essential activities. The study concludes that a hierarchical approach to tactile paving installation can improve efficiency, particularly in cities with limited funding, thus promoting broader and more effective development of inclusive urban networks. These insights are valuable for both immediate facility improvements and future transit-oriented development planning.
Abdolmajid Amirzadeh Ghasri, Saeideh Kalantari, Mahdi Tazeh
et al.
Extended Abstract IntroductionToday, erosion is a major factor in land degradation in Iran. Since a large portion of Iran is located in arid and semi-arid climates, wind erosion can be an effective means of destroying and causing damage in these areas. Nabkhas have distinct morphometric components from other erosional forms, but some of these parameters can affect the amount of wind sediment transfer. Identifying and measuring the relationship between these parameters and examining the process of changes in certain physical and chemical characteristics of sediments can have a significant impact on planning operations to reduce wind sand transfer and improve the analysis of sediment characteristics. The phenomenon of sand entering human centers in the southeast of Kerman province and Rigan city is considered a problem. This research aims to investigate the impact of the morphology of the species Tamarix, Calligonum, and Iranian mesquite on the morphometrics of the nabkhas in Rigan city and analyzing the measured parameters of the Nabkhas morphometry and their correlations using statistical methods. Material and MethodsThe city of Rigan, which covers 8600 square kilometers, is located south of Kerman. This city is one of the most important centers with the highest priority. Aerial photographs and Google Earth images were used to determine the area of Nabkhas, and a field visit was conducted to assess the development of Nebkas' territory.This area is a major source of wind erosion in Kerman province and even in the country. The severity of erosion is such that date trees with a height of more than 5 meters are buried under sand sediments. The first step was to measure the morphometric characteristics of Nabkhas along 6 one-kilometer transects. The characteristics of the Nabkhas of each of the Calligonum, Iranian mesquite, and Tamarix plants were measured separately. To investigate the characteristics of Nabkhas, the morphological characteristics of Nabkhas including height and diameter of the base were measured. The characteristics of the vegetation that forms Nabkhas were studied by measuring plant morphological factors, such as crown diameter and plant height. Statistics were collected from 44 farms that use Tamarix plants, 51 farms that use Iranian mesquite plants, and 38 farms that use Calligonum plants in total.Results The regression analysis between plant height and Nabkhas height indicates that the slope of changes in Nabkhas height compared to changes in vegetation height is higher in sedge and mesquite plants than in Calligonum. The height of Nebka is more affected by Tamarix changes than the other two plants. Based on the evaluation of the regression results between the canopy diameter and the canopy height, it can be concluded that the slope of the canopy height changes is greater than the slope of the canopy diameter changes in Calligonum and Iranian mesquite plants, respectively. It can be concluded that the Calligonum plant's crown diameter has a greater effect on Nabkhas' height changes than the other two plants. The regression results between plant height and root diameter indicate that the slope of root diameter changes is greater than that of plant height changes, respectively. It can be concluded that the height changes of the Tamarix plant are more significant in influencing the diameter changes of the Nabkhas base than the other two plants. The slope of diameter changes of the base compared to the changes of diameter of the plant crown, respectively, is higher in calligonum and mesquite plants than in Tamarix. Changes in the diameter of the crown of the Calligonum plant have a greater effect than the changes in the diameter of the other two plants on the changes in the diameter of the base of Nabkhas. Results and DiscussionNabkhas with Iranian mesquite have a longer base length in proportion to height than Nebkhas with Tamarix and Calligonum. The geomorphological characteristics of four plant species in Lut Plain's western region were examined, and it was found that the nebkhas with Tamarix have an average height of 1.5 meters and an average base of 4.2 meters. The Nabkhas' Iranian mesquite has an average height of 1.5 meters and an average base of 1.6 meters. Thus, their research results are in accord with the results of this research. According to the correlation results, the morphology of Tamarix, Calligonum, and Iranian mesquite species is significant compared to the morphometric characteristics of Nabkhas, which is consistent with the results (2 and 16). According to the regression results, Tamarix plant has a higher slope of changes in height compared to vegetation. The Calligonum plant has a higher slope of changes in height compared to diameter of plant canopy compared to the other two plants. On the other hand, the slope of changes in the diameter of the Nabkhas base compared to the changes in plant height of Tamarix is greater than that of the other two plants. The slope of the changes in the diameter of the base compared to the changes in the diameter of the plant crown is greater than that of the other two plants. The morphological characteristics of the sediments in the studied area indicate that storms are extremely strong throughout the year, causing a significant movement of sand in the area.
Razaz Waheeb Attar, Mohammad Habes, Ahlam Almusharraf
et al.
By using advanced technologies and data analytics, smart cities can establish conditions that are both inclusive and accessible, addressing the distinctive needs of disabled people. This research aims to examine the benefits of smart city technologies and develop strategies for developing environments that serve the requirements of individuals with disabilities in Saudi Arabia. Using a sequential mixed method, the study uses the social disability model. The initial phase involves gathering quantitative data from 427 individuals with disabilities in Saudi Arabia. Further, qualitative data was obtained through semi-structured interviews with a sample of four professionals employed in Saudi smart city initiatives. Quantitative data is analyzed using Partial Least Square-Structural Equation Modeling (PLS-SEM), while qualitative data is analyzed using thematic analysis. Quantitative findings revealed the robustness of the measurement model, confirming the significant effects of Smart City Initiatives on Accessibility Enhancement, Inclusive Information, and Health and Wellbeing Improvement. The respondents indicated that they are satisfied with the initiatives and their effectiveness, providing them with equal services and opportunities without discrimination. The qualitative analysis further revealed themes, i.e., Technology Integration for Accessibility, Inclusive Design, Inclusive Planning for Health, and others. Participants indicated special consideration for implementing the designs and approaches to ensure inclusivity and availability of services to disabled people. Besides, implementing infrastructure and policies to ensure the health and wellbeing of disabled people also remained prevalent. Hence, it is concluded that smart city initiatives break obstacles and improve the wellbeing of individuals with disabilities. Improved healthcare services and inclusive urban planning highlight the transformative effect of these initiatives on health and wellbeing, promoting an equitable and sustainable services environment. Finally, research implications and limitations are discussed.
Engineering (General). Civil engineering (General), City planning
Nils Wilken, Lea Cohausz, Christian Bartelt
et al.
Goal recognition is an important problem in many application domains (e.g., pervasive computing, intrusion detection, computer games, etc.). In many application scenarios, it is important that goal recognition algorithms can recognize goals of an observed agent as fast as possible. However, many early approaches in the area of Plan Recognition As Planning, require quite large amounts of computation time to calculate a solution. Mainly to address this issue, recently, Pereira et al. developed an approach that is based on planning landmarks and is much more computationally efficient than previous approaches. However, the approach, as proposed by Pereira et al., also uses trivial landmarks (i.e., facts that are part of the initial state and goal description are landmarks by definition). In this paper, we show that it does not provide any benefit to use landmarks that are part of the initial state in a planning landmark based goal recognition approach. The empirical results show that omitting initial state landmarks for goal recognition improves goal recognition performance.
Autonomous Vehicles (AVs) can potentially improve urban living by reducing accidents, increasing transportation accessibility and equity, and decreasing emissions. Realizing these promises requires the innovations of AV driving behaviors, city plans and infrastructure, and traffic and transportation policies to join forces. However, the complex interdependencies among AV, city, and policy design issues can hinder their innovation. We argue the path towards better AV cities is not a process of matching city designs and policies with AVs' technological innovations, but a process of iterative prototyping of all three simultaneously: Innovations can happen step-wise as the knot of AV, city, and policy design loosens and tightens, unwinds and reties. In this paper, we ask: How can innovators innovate AVs, city environments, and policies simultaneously and productively toward better AV cities? The paper has two parts. First, we map out the interconnections among the many AV, city, and policy design decisions, based on a literature review spanning HCI/HRI, transportation science, urban studies, law and policy, operations research, economy, and philosophy. This map can help innovators identify design constraints and opportunities across the traditional AV/city/policy design disciplinary bounds. Second, we review the respective methods for AV, city, and policy design, and identify key barriers in combining them: (1) Organizational barriers to AV-city-policy design collaboration, (2) computational barriers to multi-granularity AV-city-policy simulation, and (3) different assumptions and goals in joint AV-city-policy optimization. We discuss two broad approaches that can potentially address these challenges, namely, "low-fidelity integrative City-AV-Policy Simulation (iCAPS)" and "participatory design optimization".
José Lobo, Rimjhim M. Aggarwal, Marina Alberti
et al.
Abstract There is a growing recognition that responding to climate change necessitates urban adaptation. We sketch a transdisciplinary research effort, arguing that actionable research on urban adaptation needs to recognize the nature of cities as social networks embedded in physical space. Given the pace, scale and socioeconomic outcomes of urbanization in the Global South, the specificities and history of its cities must be central to the study of how well-known agglomeration effects can facilitate adaptation. The proposed effort calls for the co-creation of knowledge involving scientists and stakeholders, especially those historically excluded from the design and implementation of urban development policies.
This article deals with methodological challenges and presents solutions for the study of people who depart from state-subsidized housing in Ethiopia, Morocco, and South Africa. Having sold or rented out their units, these people have left and now live at dispersed locations. Assuming that many “missing people” leave state housing because of project-related shortcomings, studying the reasons for their departure is crucial to understanding standardized housing programs. “Missing people” urge scholars to emphasize the afterlives of housing policy interventions as a necessary analytical dimension. However, such research is confronted with three major methodological challenges: How is it possible to approach and study people who have disappeared from the area of a housing intervention? How can one link exploratory, in-depth qualitative accounts, rooted in subjective perceptions of the everyday, to potential structural deficiencies of standardized housing interventions? What kind of methodologies may help take into account the temporalities of displacement and resettlement? In order to overcome these challenges, the article presents innovative forms of purposive sampling and discusses analytical strategies, which—based on Clapham’s framework of “housing pathways”—bridge relational and structural perspectives to housing programs.
Abstract Background Optical coherence tomography angiography (OCTA) is a novel technology that provides a noninvasive, dye-less method to visualize the blood vessels of the retina. In the present study, we investigate macular microvascular density and the correlation of ocular and demographic factors using OCTA in Posner-Schlossman syndrome (PSS) patients. Methods This is a prospective observational study. All PSS patients and age- and sex-matched healthy subjects underwent complete ophthalmologic examination, and RE, BCVA, IOP, CCT, AL, CMT, GCIPI, RNFL, C/D ratio were recorded. The whole-image vessel density (wiVD) and whole-image perfusion density (wiPD), three-circle (1 mm central ring, 3 mm inner ring, 6 mm outer ring), and four-quadrant segmental VD and PD were calculated. Results Seventeen PSS patients and 17 healthy subjects were enrolled in this study. The mean age was 42.65 ± 11.22 years in PSS patients and 42.71 ± 10.50 years in healthy controls. IOP, CCT, and C/D ratio were higher in PSS-attacked eyes, and BCVA, OPP and RNFL thickness was lower than those in the fellow eyes (p < 0.05). BCVA and OPP were improved in the PSS-attacked eyes in intermittent period (p < 0.05). The wiVD and wiPD were lower in the PSS-affected eyes than in the fellow eyes and in the control eyes in the PSS-attacked period (p < 0.05). All segmental VD and PD was lower in the PSS affected eyes than in the healthy control eyes (p < 0.05). In intermittent period, the wiVD and wiPD were lower in the PSS-affected eyes than in the fellow eyes (p < 0.05). Age, CCT, and SSI were associated with macular wiVD and wiPD in PSS attacked period. Age and CCT were associated with macular wiVD and wiPD in PSS intermittent period. Conclusion Decreased macular superficial VD and PD was found in patients with Posner-Schlossman syndrome in attacked period and in remission. Macular wiVD and wiPD were associated with age, CCT and SSI in PSS patients.
Reinforcement learning (RL) agents are commonly evaluated via their expected value over a distribution of test scenarios. Unfortunately, this evaluation approach provides limited evidence for post-deployment generalization beyond the test distribution. In this paper, we address this limitation by extending the recent CheckList testing methodology from natural language processing to planning-based RL. Specifically, we consider testing RL agents that make decisions via online tree search using a learned transition model and value function. The key idea is to improve the assessment of future performance via a CheckList approach for exploring and assessing the agent's inferences during tree search. The approach provides the user with an interface and general query-rule mechanism for identifying potential inference flaws and validating expected inference invariances. We present a user study involving knowledgeable AI researchers using the approach to evaluate an agent trained to play a complex real-time strategy game. The results show the approach is effective in allowing users to identify previously-unknown flaws in the agent's reasoning. In addition, our analysis provides insight into how AI experts use this type of testing approach, which may help improve future instantiations.