Complexity Science Hub

🏙️ 𝗘𝘃𝗲𝗿 𝘁𝗵𝗼𝘂𝗴𝗵𝘁 𝗮𝗯𝗼𝘂𝘁 𝘆𝗼𝘂𝗿 𝗰𝗶𝘁𝘆'𝘀 𝘀𝗵𝗮𝗽𝗲? You should. When people move to a new city, they usually think about its size, its vibe, its climate. But rarely about its form. Yet city shape matters.

How far people travel on average depends on city size, of course. But it's not just about size. The shape of a city also influences how far people travel every day – and, ultimately, how much energy urban transport consumes.

In a new study, researchers at the Complexity Science Hub systematically explored how urban morphology impacts its mobility-related energy use. Using a model that captures key features such as elongation, sprawl, and building height, they simulated thousands of daily journeys across different city layouts.

𝗪𝗵𝘆 𝗶𝘁 𝗺𝗮𝘁𝘁𝗲𝗿𝘀 𝗻𝗼𝘄
The exact numbers may differ, but the trend is clear: more and more people are living in cities. While the UN projects that seven in ten people will live in cities by 2050, a recent CSH study found that by 2100, only 38% of humanity will live in cities with over one million inhabitants (https://csh.ac.at/news/only-38-of-the-worlds-population-expected-to-live-in-large-cities-by-2100-study-challenges-current-forecasts/). As cities grow, so does their influence on global energy demand. Urban transport accounts for a significant share of that consumption. And this scales with average journey length – which depends not just on city size, but on city shape.

𝗦𝗼𝗺𝗲 𝗸𝗲𝘆 𝗿𝗲𝘀𝘂𝗹𝘁𝘀 𝗼𝗳 𝘁𝗵𝗲 𝘀𝘁𝘂𝗱𝘆
⭕ Round and compact cities minimize travel distance compared to elongated, sprawling ones. Elongation increases distance nonlinearly.

🔺 Pyramid-shaped profiles – where taller buildings concentrate in the center – boost travel efficiency. Moderately pyramid-shaped layouts reduce average travel distances by 20–25%.

🌍 This matters especially in rapidly growing regions. Africa will be home to 40% of the world's population by 2100, with most growth concentrated in large urban clusters. Planning decisions made today will shape global energy demand and the daily lives of hundreds of millions.

𝗘𝘅𝗽𝗹𝗼𝗿𝗶𝗻𝗴 𝗰𝗶𝘁𝘆 𝘀𝗵𝗮𝗽𝗲𝘀 𝘆𝗼𝘂𝗿𝘀𝗲𝗹𝗳
The team also created an interactive visualization and calculator where you can adjust city parameters and see how each change affects travel distance – a resource for planners, policymakers, and anyone curious about cities.

🔗 Explore the visualization: https://vis.csh.ac.at/cities-morphology/ #/
📖 Read the full story: https://csh.ac.at/news/why-we-need-to-consider-city-shapes-to-save-energy-water-and-the-climate/

The people behind this research are: Rafael Prieto-Curiel, Tobias Batik, Guillermo Prieto Viertel, Jiaqi Liang, Liuhuaying Yang, Dániel Kondor 👏