Vertical 15-minute city: Modeling urban density and functional mix with multi-source geospatial data

IF 6.6 1区经济学 Q1 URBAN STUDIES

Cities Pub Date : 2025-10-06 DOI:10.1016/j.cities.2025.106516

Yang Chen , Xin Yang , Xin Li , Ling Yang , Sifan Cheng , Guoan Tang , Filip Biljecki

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引用次数: 0

Abstract

The 15-minute city concept emphasizes accessible urban living by ensuring essential services are reachable within walking or biking distance. However, most evaluations rely on two-dimensional (2D) analyses, neglecting the vertical complexity of high-density cities. This study introduces a 3D framework for assessing 15-minute accessibility in Nanjing, China. Using natural language processing and rule-based methods, we construct a 3D functional composition dataset from multi-source data. We then develop floor-level proximity indices that account for both horizontal travel time and vertical circulation (e.g., stairs, elevators). Analyzing over 90 million simulated trips, we find that accessibility generally declines with building height, though access to offices and commercial facilities improves at 20th or higher floors. Spatial inequalities emerge not only between central and peripheral zones but also across building levels and regional GDP levels, with a U-shaped disparity tied to distance from downtown. Notably, 11%–17% of trips considered accessible in 2D analyses exceed the 15-minute threshold when vertical travel is included. Our findings highlight the need to incorporate vertical space in 15-minute city evaluations and offer a scalable method to support inclusive, fair, and livable 3D urban planning with the background of 15-minute city.

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垂直15分钟城市：基于多源地理空间数据的城市密度和功能组合建模

15分钟城市概念强调城市生活的便利性，确保步行或骑自行车即可获得基本服务。然而，大多数评价依赖于二维（2D）分析，忽视了高密度城市的垂直复杂性。本研究引入了一个3D框架来评估中国南京的15分钟可达性。采用自然语言处理和基于规则的方法，从多源数据中构建三维功能组合数据集。然后，我们开发楼层接近指数，考虑水平旅行时间和垂直循环（例如，楼梯，电梯）。通过对超过9000万次模拟出行的分析，我们发现可达性随着建筑高度的增加而下降，尽管通往办公室和商业设施的可达性在20层或更高的楼层有所改善。空间不平等不仅出现在中心和周边地区之间，也出现在建筑水平和地区GDP水平之间，u型差异与与市中心的距离有关。值得注意的是，在2D分析中，11%-17%的可达行程超过了15分钟的阈值，其中包括垂直行程。我们的研究结果强调了将垂直空间纳入15分钟城市评估的必要性，并提供了一种可扩展的方法，以15分钟城市为背景，支持包容、公平和宜居的3D城市规划。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Cities URBAN STUDIES-

CiteScore

11.20

自引率

9.00%

发文量

517

期刊介绍： Cities offers a comprehensive range of articles on all aspects of urban policy. It provides an international and interdisciplinary platform for the exchange of ideas and information between urban planners and policy makers from national and local government, non-government organizations, academia and consultancy. The primary aims of the journal are to analyse and assess past and present urban development and management as a reflection of effective, ineffective and non-existent planning policies; and the promotion of the implementation of appropriate urban policies in both the developed and the developing world.