Towards Inclusive Smart Cities

1. Introduction to the Applications, Challenges, and Opportunities in Inclusive Smart Cities

Today, due to the widening of the wealth gap, the intensification of climate change, and the acceleration of both population growth and population aging, our cities are being tested by multiple economic, environmental, and social challenges, including, but not limited to, urban sprawl, urban gentrification, marginalization, housing crisis, tent city, urban flooding, urban heat island, environmental migrants, urban slums, tent cities, urban aging, and empty nesters [1,2,3,4,5,6]. In the past few years, pandemics and regional conflicts have undoubtedly exacerbated these problems [7,8]. To some extent, our cities are increasingly becoming less inclusive.

In recent years, on the other hand, on top of novel concepts and strategies of urban planning and design [9,10,11], emerging technologies such as big data, cloud computing, Internet of things (IoT), advanced information and communications technology (ICT) like 5G/6G, artificial intelligence (AI), blockchain, robotics, automated vehicles, and mixed reality have undoubtedly provided infinite possibilities for the development of smart cities, and also brought opportunities to solve the problems that plague our cities [12]. Furthermore, in accordance with the political–societal systems, the whole value chain for constructing and maintaining our cities can be optimized for higher return on investment (ROI) by design for manufacturing and assembly (DfMA), robot-oriented design (ROD), and on-site automation in order to achieve better affordability, adaptability, accessibility, resilience, and circularity for more dwellers [13,14]. As a result, many cities in the developed world, including, but not limited to, Barcelona, Copenhagen, Dubai, Hong Kong, London, Singapore, and Tokyo, have started to adopt smart city technologies to improve their residents’ quality of life [12], and meanwhile, cities in developing countries are also accelerating the pace of smart city adoption [15,16]. Specifically, these smart city adoptions can be enhanced by a menu of socio-technical categories of applications, including healthcare, governance, environment, mobility, energy, safety/security, infrastructure, and education [17].

However, while the technological advancements of smart cities are emphasized, the inclusivity in smart cities is less discussed [18]. As a newly emerging urban model concept, inclusive smart cities currently lack a clear definition, although they are usually characterized by their core focus on recognizing and addressing the needs of all individuals, particularly older adults and persons with disabilities [19]. Some criticisms point out that current smart city visions may hinder citizens’ freedom due to dependence on technologies [20,21], while others worry that vulnerable groups such as older adults and people with disabilities may be left behind due to the digital divide [22,23]. More importantly, it is necessary to remain cautious about the potential misuse of the smart city concept, particularly where inclusivity is overlooked [24]. As some researchers rightly point out, inclusivity is essential to enable an effective and sustainable transition to smart cities [25]. Therefore, advancing research on inclusive smart cities has become an urgent priority.

This Special Issue’s purpose is to attract relevant high-quality research articles on the planning, operation, and maintenance processes of inclusive smart cities, or smart cities for all, using technologies that are friendly to all city dwellers, especially those who are vulnerable, regardless of their age, gender, ethnicity, education, wealth, and social status. The scopes of the submissions are on the micro-, meso-, and macro levels of smart cities. As a result, articles from technological, economic, and social perspectives, including critical review articles, are all included.

2. Overview of the Special Issue

The Special Issue, entitled “Inclusive Smart Cities”, attracted contributions from many experts around the world associated with the theme, and finally, after rigorous peer review processes, 13 high-quality articles including 8 research articles, 4 review articles, and 1 project report were published in this Special Issue, covering a wide range of relevant topics on the micro-, meso-, and macro levels of inclusive smart cities. This section presents a concise summary of the 13 contributions, aiming to encourage readers to explore them in greater depth. The topics of interest for this Special Issue are reflected in the word cloud in Figure 1, where larger font sizes represent more frequent occurrences of terms.

The paper titled “The Role of Smart Homes in Providing Care for Older Adults: A Systematic Literature Review from 2010 to 2023” by Vrančić et al. offers a comprehensive analysis of 58 studies to understand how smart home technologies (SHTs) support aging populations. The review explores the benefits, challenges, and ethical implications of SHTs for older adults, focusing on enhancing safety, health monitoring, autonomy, and social connection. It highlights promising innovations such as automated health systems, emergency alerts, and user-friendly interfaces, which can empower older adults to age in place independently. However, significant challenges—such as privacy concerns, system complexity, high costs, and low technological literacy—hinder widespread adoption. The review also addresses ethical considerations like autonomy, informed consent, and human dignity. It calls for user-centered designs, accessible technologies, and educational initiatives to boost older adults’ acceptance. Technological integration through IoT, AI, and wearable sensors is emphasized for effective monitoring, while the study underscores the need for multidisciplinary collaboration in designing inclusive and ethical smart home environments. Ultimately, the review offers actionable recommendations for developers, researchers, and policymakers to promote supportive, human-centered smart home solutions for aging societies.

The paper “Inclusive MicroMob: Enhancing Urban Mobility Through Micromobility Solutions” by Rollandi et al. explores the integration of novel micromobility devices into Swiss urban environments, with a primary focus on Lugano. It introduces the Genny Zero, a self-balancing vehicle, and evaluates its performance through urban analysis, real-world experimentation, and participatory processes. The study identifies key challenges such as regulatory gaps, infrastructure limitations, and social acceptance. Data were collected via sensors and depth cameras during urban tests, revealing that the Genny Zero is most effective in areas with designated cycling infrastructure and smaller slopes. The project also highlights the importance of participatory urban governance, showing that public perception shifts positively after hands-on experience. The social study revealed generational differences in attitudes toward micromobility and underscored the need for inclusive, safe, and well-regulated systems. Policy recommendations include adaptive regulations, improved infrastructure, and integrating micromobility with the existing transport networks. Overall, the project demonstrates that micromobility can enhance urban sustainability and inclusivity if technological, spatial, and social factors are addressed collectively.

The paper “Insights from Smart City Initiatives for Urban Sustainability and Contemporary Urbanism” by Veloso et al. provides a comprehensive review of smart city initiatives in four cities around the world—Barcelona, Helsinki, Medellin, and Singapore—evaluating their contributions to sustainable urban development across six domains: mobility, governance, environment, people, living, and economy. Based on 71 peer-reviewed articles, the study finds that most smart city initiatives emphasize technology-driven governance and environmental strategies, but often lack comprehensive, inclusive frameworks addressing social equity and holistic sustainability. Barcelona and Helsinki excel in citizen-centric and participatory governance, while Singapore leads in ICT innovation but relies heavily on top-down strategies. Medellin’s focus is on social inclusion and infrastructure renewal in disadvantaged areas. The study highlights an uneven focus across domains, with “smart people,” “living,” and “economy” receiving less attention despite their relevance to urban equity and resilience. It calls for context-sensitive, integrated approaches that combine digital innovation with inclusive, adaptive planning practices. The authors advocate standardized assessment tools to measure sustainability impacts and stress the need for smart city strategies that prioritize social needs and long-term urban resilience beyond technological deployment.

The paper “Smart Cities, Digital Inequalities, and the Challenge of Inclusion” by Kolotouchkina et al. critically examines how smart city developments often deepen digital inequalities and fail to inclusively engage all city dwellers. While smart cities aim to improve urban governance through digital innovation, they tend to prioritize tech-savvy, affluent, and younger populations, thereby marginalizing vulnerable groups such as older adults, people with disabilities, migrants, and low-income communities. These groups face barriers in digital access, skills, and participation due to factors like affordability, lack of education, limited self-efficacy, and systemic ageism or ableism. To address these challenges, the authors propose a reflective framework focusing on three key questions: Who is included or excluded? What is the value of digital inclusion? How can inclusive governance be ensured? The framework emphasizes digital accessibility, digital citizenship, equal representation, and co-creation in policymaking. It aims to guide the development of inclusive urban policies that foster digital rights, ethical data governance, and participatory practices. Eventually, the paper advocates a citizen-centric smart city model where inclusion is not incidental but foundational to urban digital transformation.

The paper titled “Embedding Circular Economy in the Construction Sector Policy Framework: Experiences from EU, U.S., and Japan for Better Future Cities” by Marzani et al. explores how Circular Economy (CE) principles are embedded in construction sector policies across the EU (specifically Italy and Germany), the US, and Japan, aiming to guide the transition toward sustainable and smart urban development. Through comparative policy analysis, it highlights diverse approaches: the EU integrates CE within comprehensive strategies like the European Green Deal and New Circular Economy Action Plan; Japan anchors CE in national laws focused on resource efficiency and long-term environmental planning; while U.S. initiatives are driven more by city-level actions due to limited federal support. Common policy targets include reducing resource use, increasing recycling rates, promoting the reuse of construction materials, and minimizing construction and demolition waste. Despite growing recognition of CE, most policies still emphasize end-of-life waste management, with limited attention to the entire building lifecycle, particularly the use and maintenance phases. Moreover, the integration of digital technologies—such as Building Information Modeling (BIM), digital twins, and material passports—remains limited, with Japan as an exception. The paper underscores the need for policy harmonization and stronger inclusion of digital tools to enhance material traceability and lifecycle optimization. Furthermore, it advocates research-informed, digitally enabled CE policies as key to achieving more resilient, inclusive, and circular smart cities.

The paper “The Use of Smart Technology for Creating an Inclusive Urban Public Space” by Itair et al. investigates the critical role of urban public spaces in community development and proposes a smart framework to enhance their inclusivity, particularly in developing regions. Using the city of Nablus, Palestine, as a case study, the authors assess public space inclusivity through a framework of eight indicators: spatial distribution, typology, facilities and services, green and humid areas, governance and management, safety, user demographics, and user satisfaction. The findings reveal that public spaces in Nablus are limited and unevenly distributed, particularly disadvantaging low-income populations, women, children, and people with disabilities. Users expressed dissatisfaction with accessibility, safety (especially at night for women), lack of green areas, and inadequate facilities. The study introduces the concept of “smart public spaces,” leveraging technologies such as IoT, mobile apps, and AI for real-time monitoring, service optimization, and environmental sustainability. The smart public space framework comprises six layers—governance, physical infrastructure, data collection, communication, server infrastructure, and smart services—designed to promote citizen engagement, safety, and eco-friendliness. This approach aims to support the UN’s Sustainable Development Goal (SDG) 11.7 by making urban public spaces more inclusive, accessible, and responsive to community needs.

The paper titled “Fit Islands: Designing a Multifunctional Virtual Urban Community to Promote Healthy Aging for Chinese Older Adults” by Shen et al. addresses the urgent challenge of aging populations in emerging economies, particularly in China. In response to the challenges of rapid population aging, health issues, digital divides, and pandemics in emerging economies, the research team creates a virtual urban community that encourages physical activity, cognitive engagement, and social interaction. Designed to be affordable, inclusive, and adaptable, Fit Islands uses motion capture via standard cameras, avoiding the need for intrusive wearables and costly sensors. It includes age-friendly UI, customizable gameplay, health education, and a reward system. The game is inspired by Chinese seniors’ behaviors, such as square dancing, and offers both seated and standing exercises. A standard development framework for Exergames in emerging economies is proposed and applied. Functional tests with Chinese seniors demonstrated the system’s feasibility and user-friendliness. The study concludes that Fit Islands can enhance the well-being of older adults and serves as a replicable model for other aging societies.

The paper “Smart Cities for All? Bridging Digital Divides for Socially Sustainable and Inclusive Cities” by Colding et al. explores how smart city development, while offering climate-proofing benefits, risks reinforcing social exclusion due to digital divides. Using Amartya Sen’s capability approach, the authors analyze how personal, social, and environmental factors affect individuals’ ability to convert digital resources into real opportunities or “functionings.” The paper identifies three levels of digital divides: access (first-level), digital skills and participation (second-level), and differential benefits from ICT use (third-level). These divides disproportionately affect marginalized groups such as the elderly, low-income populations, and people with disabilities. The authors argue that digital technologies, often touted as universally beneficial, can serve as “non-choice default technologies,” excluding those without digital proficiency or access. To build inclusive and socially sustainable smart cities, the paper recommends creating institutions that enhance capabilities, safeguarding analog options for public services, and integrating citizen feedback. A unified governing body is proposed to monitor inclusivity and promote equity-focused policies. Overall, the paper calls for a shift from a technocratic, one-size-fits-all model to a socially inclusive approach rooted in human capabilities and climate justice.

The article titled “Redesigning Municipal Waste Collection for Aging and Shrinking Communities” by Pandyaswargo et al. addresses Japan’s pressing challenge of maintaining municipal waste collection amid rapid aging and depopulation. Researchers surveyed 1000 Japanese residents to understand preferences around contactless, collective waste disposal. Surprisingly, older adults were more willing to walk longer distances (up to 5 min) to waste collection points and were less concerned about disease transmission than younger individuals. Single-person households also preferred disposal sites placed farther from their homes and generated less waste. Based on these findings, two redesign strategies were proposed: (1) centralized large-container collection to reduce labor demand, and (2) automated pickup using robotics and autonomous mobility. While each has trade-offs—such as increased energy needs or potential resistance from users—they support more sustainable, inclusive systems. These insights not only guide Japan’s smart city transition under the “Society 5.0” concept but also offer lessons for other aging and shrinking communities worldwide.

The paper titled “AI-Driven Prediction and Mapping of Soil Liquefaction Risks for Enhancing Earthquake Resilience in Smart Cities” by Katsuumi et al. presents an AI-driven model for predicting and mapping soil liquefaction risks to enhance earthquake resilience in smart cities, with Yokohama, Japan, as a case study. Using ensemble machine learning techniques—combining artificial neural networks and gradient boosting decision trees—the model integrates geotechnical and geographical data to assess soil susceptibility during seismic events. The study introduces high-resolution risk maps based on predicted N-values and soil classifications, validated through the Soil Liquefaction Potential Index (LPI). Among three prediction procedures, the bottom-up approach (i.e., predicting from depth upward) proved most accurate. The model demonstrated strong performance despite limited data, highlighting ensemble learning’s effectiveness in improving prediction accuracy. This approach offers significant advancement over traditional empirical methods, enabling smarter urban planning, proactive disaster mitigation, and more resilient infrastructure design in earthquake-prone regions. The study underscores the transformative potential of AI in geotechnical engineering and smart city development.

The paper titled “Transitioning to a Low-Carbon Lifestyle? An Exploration of Millennials’ Low-Carbon Behavior—A Case Study in China” by Wu et al. explores how Chinese millennials engage in low-carbon behaviors and what drives or hinders their adoption of sustainable lifestyles. Using qualitative methods based on in-depth interviews with 50 well-educated Chinese millennials from diverse sectors and regions, the study identifies key patterns in attitudes and actions. The study finds that millennials generally show a positive attitude toward low-carbon living. Women are more active in domestic low-carbon actions, such as energy conservation and waste reduction, although they are underrepresented in decision-making roles within organizations. Millennials’ low-carbon behaviors are evident in clothing choices (e.g., second-hand or sustainable materials), food habits (e.g., reduced meat and takeout), transportation (e.g., use of public transit and electric vehicles), and social interactions (e.g., participating in digital environmental initiatives like Ant Forest). Barriers include limited awareness, perceived inconvenience, quality concerns about sustainable products, and a lack of effective governance or infrastructure. Conversely, enablers include economic incentives, technological advancements, personal values, and governmental policies. The study concludes that systemic support and cross-sector collaboration are essential to foster deeper lifestyle shifts among millennials toward carbon neutrality.

The study titled “Probabilistic Causal Modeling of Barriers to Accessibility for Persons with Disabilities in Canada” by Zakir et al. applies probabilistic causal modeling to analyze accessibility barriers faced by persons with disabilities (PWDs) in Canada using data from the 2022 Canadian Survey on Disability. By integrating exploratory factor analysis, structural equation modeling, and Bayesian networks, the authors identify how demographic factors such as age, gender, and disability type influence the likelihood and frequency of encountering barriers in communication, transportation, and digital services. The study confirms strong causal relationships between disabilities and specific accessibility challenges, with pain, mobility, and mental health conditions being most affected. It also demonstrates the feasibility of generating synthetic data to address limitations in real-world datasets while preserving privacy. The findings aim to inform inclusive smart city planning and policy by offering a data-driven framework to predict and address future accessibility issues, ultimately supporting a more equitable and barrier-free environment for PWDs in urban settings.

The paper “Game-Theoretic Analysis of Policy Impacts in Competition Between Reverse Supply Chains Involving Traditional and E-Channels” by Aghaei et al. investigates the strategic interactions between two types of reverse logistics-based supply chains—one using only traditional channels (T-SCs) and the other using both traditional and e-channels (H-SCs)—within the context of smart cities and circular economy goals. Using game-theoretic models (Nash equilibrium and Nash–Stackelberg scenarios), the study evaluates how five policy levers—incentive pricing, return quality level, advertising investment, transportation investment, and return processing time—affect economic (i.e., profitability) and environmental (i.e., return rates) outcomes. The findings show that the hybrid supply chain (H-SC) consistently outperforms the traditional model in both profitability and return rates due to its dual-channel flexibility. Specifically, traditional supply chain leadership in a Nash–Stackelberg structure yields the highest overall profitability for both systems. The study also provides sensitivity and Pareto analyses, revealing that return quality and processing time are critical for H-SCs, while advertising investment and processing time are most influential for T-SCs. These insights highlight the need for balanced, policy-driven strategies to optimize sustainable supply chain operations in smart cities.

3. Conclusions

In conclusion, this Special Issue highlights that the future of smart cities must be measured not only by their technological advancement but also by their capacity to foster inclusivity, equity, and resilience. The presented contributions demonstrate that inclusivity is both a guiding principle and a practical necessity for sustainable urban transformation, ensuring that marginalized voices are heard and that digital innovation benefits all. By critically examining governance models, citizen participation, design practices, and emerging technologies, the collected papers underline from micro-, meso-, and macro levels that inclusive smart cities are not only promising but also achievable through deliberate, collaborative, context-sensitive, and multi-level approaches. As cities worldwide continue to adopt smart solutions, the insights from this Special Issue provide a foundation for researchers, urban planners, policymakers, and innovators to co-create urban environments that are technologically sophisticated, socially just, environmentally friendly, and most importantly, accessible to everyone.