Fitting the Chrono Urbanism of 15-Minute City Principles into the City of Semarang, Jawa-Indonesia: A GIS-Based Identification

The concept of the 15-Minute City, developed by Carlos Moreno, offers an inspiring model for urban living that prioritizes people over cars [1]. It envisions neighborhoods where everyone can reach essential services—like workplaces, schools, healthcare, shops, and recreational areas—within just a 15-minute walk or ride using small, sustainable vehicles. This approach encourages local living, lessens the need for long commutes, and promotes healthier, more equitable, and greener cities. However, although the idea is appealing, applying it directly to non-European cities such as those in Indonesia demands thoughtful adaptation and a keen understanding of local circumstances.

Unlike a well developed and completed urbanized European cities, urban development in Indonesia has followed a different path. Rather than being shaped around walkability and compact, mixed-use districts, Indonesian cities have largely expanded with low-rise, spread-out housing, significant urban sprawl, and a heavy reliance on motorcycles and cars as the main modes of transportation [2]. This pattern is especially visible in fast-growing cities like Semarang, Surabaya, and the vast sprawl of Jakarta's metropolitan area. The prevailing approach of developing large, single-purpose housing estates—often gated and isolated from the rest of the city—has led to fragmented urban areas where homes, jobs, and services are physically separated. As a result, residents frequently have to travel considerable distances to reach workplaces and amenities [3, 4].

As a result, bringing the 15-Minute City concept to Indonesian cities isn't as simple as replicating a European model. True implementation demands careful adaptation that deeply considers Indonesia's unique urban patterns, economic realities, cultural traditions, and systems of local governance. Rather than aspiring to the rigid geographic proximity often implied by the 15-minute metric in walking terms [5], Indonesian cities must reframe the concept based on functional proximity, combining physical, social, and digital accessibility.

In particular, this locally adapted vision recognizes that major Indonesian cities have traditional neighborhoods known as kampung, which serve as the historical core of urban development. These kampungs provide a valuable—though often underappreciated—foundation for local living. Despite their informal origins, many kampungs already demonstrate central elements of the 15-Minute City: walkable areas, diverse land uses, strong community bonds, and easy access to essential services [6]. Rather than replacing these neighborhoods through top-down modernization or large-scale vertical housing projects, urban policies should focus on upgrading and linking kampungs to the wider city. By doing so, planners can strengthen and expand the existing patterns of proximity-based living that function effectively at a neighborhood level, using a locally informed, bottom-up approach [7].

In expansive residential developments, especially those comprised mainly of private landed homes, it's crucial to implement retrofitting strategies. One effective approach is to create localized service hubs-compact groupings of shops, clinics, schools, public spaces, and co-working areas located within or near housing clusters. These hubs would allow residents to conveniently meet most daily needs close to home, reducing dependence on long commutes or distant central services. Encouraging this transformation through more flexible zoning laws would further help blend different functions into residential neighborhoods. However, with the mix of kampung and a more contemporary larger housing development and market mechanism property would provide a dynamic urban structure in Indonesia [8].

Mobility must also be reimagined within this context. In cities where walking culture is limited due to poor pedestrian infrastructure and tropical climate conditions, the 15-minute radius could be realistically extended through active and informal modes of transport, such as cycling, electric bikes, and motorcycle taxis. This is not a compromise but a pragmatic reflection of Indonesia’s existing transport ecosystem [9].

Transitioning toward the 15-Minute City concept in Indonesia requires a gradual and flexible approach. Efforts must address the country's varied urban environments, from dense kampung neighborhoods and suburban outskirts to transit-oriented developments. These challenges provide valuable opportunities to test the model, enabling lessons to be learned from both achievements and setbacks before implementing it on a broader scale. Success should be measured not just by how quickly people can reach destinations, but also by considering factors such as social equity, environmental health, accessibility, and community well-being.

At this point, numerous urban planning scholars in Indonesia have recognized Carlos Moreno’s 15-Minute City concept as a significant shift toward more decentralized, environmentally friendly, and spatially just urban governance [10].

Yet, in Asia—and particularly Indonesia—there is a tendency to focus intently on these urban transformation goals. The 15-Minute City should not be considered a one-size-fits-all solution, but rather a flexible idea that adapts to the unique social, spatial, and cultural conditions of each location. In Indonesia, this model has been reimagined as the 15-Minute City, representing a significant step toward creating more livable, inclusive, and resilient urban environments that respond thoughtfully to local needs and characteristics [11, 12].

In the Indonesian context, realizing the 15-Minute City calls for a distinctly local adaptation—one that acknowledges the country's informal urban patterns, builds upon established community frameworks, and reimagines proximity in terms of practical accessibility, social equity, and quality of urban life [13]. By adopting this tailored approach, Indonesian cities can progress toward more sustainable, resilient, and inclusive futures, capturing the essence-if not the exact form-of the original 15-Minute City model. To date, much of the research on this concept has relied on simplified analog methods, such as drawing a circle around a central point to represent a reachable area within a set time, without accurately reflecting the complexity of real urban environments. This study addresses that gap by harnessing the power of Geographic Information Systems (GIS) to deliver a detailed analysis of spatial relationships within Indonesian cities.

GIS is a technological tool designed to store, analyze, and share geographic data, offering important advantages for urban planning. It enables more precise mapping of land use and infrastructure, especially in assessing the reach and coverage of public facilities, thus supporting better-informed decision-making processes [14].

Carlos Moreno's 15-Minute City concept represents a significant evolution in urban thinking by prioritizing the human scale, temporal accessibility, and functional diversity within walkable or cyclable neighborhoods. As urbanization accelerates in the Global South, especially in Indonesia, the potential for a proximity-based city model raises critical questions: Can a concept rooted in Europe’s dense, historic cities translate effectively to Indonesia's more sprawling, car-dependent, and culturally diverse urban landscapes?

To address this, we must explore the theoretical foundations of the 15-Minute City and critically assess its adaptation within the Indonesian context. The concept is built upon four central principles: (1) ensuring that essential services—such as education, healthcare, commerce, and recreation-are accessible within a 15-minute radius for all residents; (2) fostering mixed-use neighborhoods that integrate housing, business, and community services; (3) promoting a compact urban form to make proximity practical; and (4) supporting vibrant local communities.

While originally developed in Europe, the 15-Minute City embodies universal values—such as proximity, local living, and community vitality—that resonate with Indonesian urbanism. However, successful implementation in Indonesia requires careful contextualization. This involves acknowledging local urban forms, leveraging the strengths of informal settlements, reforming land-use policies, and empowering community participation.

This study selected Banyumanik District and Central Semarang District as focus areas due to their dense, compact characteristics, making them promising candidates for applying the 15-Minute City concept. Banyumanik District, located in the southern part of Semarang City, acts as a sub-center for urban development and is largely shaped by residential neighborhoods, educational facilities, commercial centers, and public services. In contrast, Central Semarang District forms the heart of the city, hosting a concentration of economic, trade, and service activities. This area features a wide range of amenities, such as shopping malls, hotels, office buildings, and commercial hubs. The functional diversity, high mobility, and solid infrastructure present in both districts make them ideal for studying short-distance, sustainable urban planning. The research aims to determine how well the urban zones of Semarang-considering their low-density, landed housing, and the spread of public services—align with the geometric principles of the 15-Minute City model.

This study utilizes a spatial quantitative analysis framework, drawing on GIS [18], to examine how the 15-Minute City concept [19] could be implemented in selected urban areas of Banyumanik and Semarang Tengah within the City of Semarang.

The main goal is to evaluate the spatial distribution, accessibility, and interconnectedness of essential urban services and residential areas within a 10-minute travel window. To establish a robust methodological foundation, four principal spatial analysis techniques were employed:

1. Kernel Density Estimation (KDE), this approach maps patterns of housing concentration, clarifying how clusters of residences affect access to urban services. In density analysis, KDE identifies and visualizes how data points—such as homes—are distributed across a given area, highlighting zones of higher or lower population density.
2. Isochrone Mapping on QGIS, this technique illustrates the areas accessible within a 10-minute walk or bike ride, revealing service catchment zones based on travel time rather than simple distance. By using isochrone maps, the study identifies how far residents can realistically travel to reach amenities, providing a more accurate measure of accessibility.
3. Closest Facility Analysis, by simulating a cycling speed of 15 km/h (according to some of previous researches regarding the average speed of cyclists [20, 21]), this analysis determines the fastest routes between residential areas and essential services like schools, clinics, and markets. It highlights the efficiency of access, revealing mismatches where population clusters are not well served by urban facilities. This analysis can also factor in travel barriers, start times, and duration, ultimately suggesting the most effective routes and calculating travel costs.
4. Urban Network Analysis (UNA), this method evaluates how well streets and services are interconnected, assessing aspects like node density, network reach, and centrality. UNA offers a deeper understanding of transportation and service integration, considering the three-dimensional position and role of buildings. It calculates five core network centrality indices:

• Reachness, to measure how accessible a location is, factoring in function, travel distance, and nearby building density.
• Gravity, to assess node centrality in the road network by tallying reachable nodes within a set radius, with influence decreasing as distance increases.
• Betweenness, to indicate which locations serve as key connectors between points, based on volume, block size, and network structure. If multiple shortest paths exist, their influence is divided accordingly.
• Closeness, to evaluate proximity to other locations, emphasizing how isolated or integrated a neighborhood may be.
• Straightness, to measure the directness of routes—higher values indicate more efficient, less circuitous paths.

By integrating these analytical tools, the study provides a nuanced, data-driven assessment of spatial fairness, time-based accessibility, and the effectiveness of urban design in the context of the 15-Minute City model. The findings offer practical insights for developing more sustainable, people-oriented urban spaces in Indonesian cities, especially those with polycentric patterns and a prevalence of single-family homes.

As depicted in Figure 1, the research process began with the identification of core challenges, a comprehensive literature review, and the careful selection of study areas based on data availability and relevance. The subsequent phase focused on gathering data through formal requests to local government bodies and digital mapping techniques.

Finally, the four principal methods—Kernel Density Estimation, Isochrone Mapping, Closest Facility Analysis, and Urban Network Analysis—were applied to rigorously evaluate how effectively public facilities in the study areas align with the principles of the 15-Minute City.

The data utilized throughout this study were sourced from multiple avenues. Frequent coordination and meetings with the Urban Planning Board Agencies of Semarang City facilitated efficient data collection. Additional information was gathered through OpenStreetMap and the Semarang City geoportal, supplemented by on-screen digitization using Google Earth Pro. For data processing, both ArcMap and QGIS software were employed. Table 1 below summarizes the research data.

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Figure 1. Methodological framework

In contrast, Table 13 shows that Central Semarang, while exhibiting a more organized urban structure, is challenged by significant distances between facilities and a dense, narrow road network. As a result, Banyumanik emerges as a stronger closeness for implementing the 15-Minute City concept, thanks to its spatial characteristics, road network design, and distribution of public amenities. Nevertheless, both districts offer promising opportunities for growth if guided by thoughtful planning aimed at achieving sustainable and inclusive urban development.

A comprehensive analysis of the various methods underscores Banyumanik District’s strong conformity to the core tenets of the 15-Minute City paradigm. The findings derived from the Kernel Density method indicate a higher concentration of residential buildings in Banyumanik, while the Isochrones approach demonstrates the district’s extensive accessibility to public facilities, attributed to their well-planned distribution. Further, the Closest Facility method accentuates Banyumanik’s advantages, as its mixed land use pattern significantly enhances access to vital amenities. The UNA method corroborates these observations by revealing that the district benefits from an integrated road network and robust building connectivity, leading to superior index values.

Collectively, these results affirm that Banyumanik District effectively embodies the fundamental components of a 15-Minute City: elevated population density, convenient access to essential public facilities, and a vibrant mixture of land uses and economic activities. As such, Banyumanik emerges as an exemplary area for advancing the implementation of the 15-Minute City concept. Nonetheless, the distinctive spatial features of Semarang City preclude the wholesale application of this model across all districts. A citywide, nuanced evaluation remains necessary to accurately identify which areas are optimally aligned with the 15-Minute City framework.