The 15-minute city: An affordable solution toward freedom of mobility for all in a decarbonized world?
April 26, 2023
Although the idea of the 15-minute city has roots in historic city planning, it has become more prevalent in the face of the COVID-19 pandemic(1). From Melbourne to Milan, urban cities globally have begun implementing frameworks to increase accessibility to essential amenities within walking distance(2). As cited by panelists Yamina Saheb and Ben Welle during the Freedom of Mobility Forum 2023 debate held on March 29, one of the potential solutions to guarantee universal access to basic services while cutting greenhouse gases lies within this idea of the 15-minute city(3). The question then arises about the true viability of this urban planning concept for all populations and not only a happy few.
The “15-minute city”: Providing easier access to basic amenities to shorten urban trip lengths
The term was first introduced by urbanist and university professor Carlos Moreno as part of the vision of a self-sufficient community in a proposal he made following the 2015 Paris Climate Change Conference. The 15-minute city consists of local neighborhoods, each with access to basic amenities such as grocery stores, health services, schools, parks, arts and culture institutions, etc. within a 15-minute trip by foot or bicycle. The concept seeks to combat carbon emissions, reduce daily commute times, and increase affordability and accessibility for all residents(1).
There are geographical and physical limitations to implementation of the 15-minute city
Since World War II, urban planning models across the world have tended to separate areas where people live from areas for work, shopping or socializing and introduced lower-density rules. Transport infrastructure investment has favored the expansion of urban roads, highways and parking, making walking and cycling impossible in some areas(4). In the U.S., the 15-minute principles are far from being a reality: Americans travel 7 to 9 miles (between 11 and 15 km) on average for shopping and recreational activities, which is far longer than the distance someone can cover within 15 minutes by foot or bike. In contrast, the average distance per person in Greece is 5.6 km (3.5 miles)(5). The median U.S. city resident makes only 12% of their daily trips within 15 minutes, although there is significant regional variation across the country(6). Because of inherited urban planning, there seems to be difficulty in implementing the 15-minute city concept in established urban areas where land use patterns and infrastructure are already in place. Additionally, the concept may not be practical in areas with low population density or in low-income communities where transportation options are limited.
Reducing travel across neighborhoods could exacerbate the social isolation of marginalized communities
More localized trips and more access to local amenities is associated with higher levels of experienced segregation for low-income residents because the opportunities for higher-income social interactions in most cities are located away from low-income neighborhoods. One consequence of 15-minute cities may be the increased isolation of the poor. On the other hand, a study conducted by the U.S. National Bureau of Economic Research shows that there is no strong association between 15-minute usage and experienced segregation for residents of high- and upper-middle-income neighborhoods(6). In fact, as local trips increase, residents of high-income neighborhoods experience more social mixing. The opposite is true for residents of low-income neighborhoods. With more emphasis on local trips within 15-minute cities, segregation of lower-income groups becomes more apparent than that of higher-income groups. In New York, residents of the neighborhoods in the poorest 10% of the population (income group 1 on the left-hand side of the graph) make about 60% of their trips within 15-minute areas, while residents of the richest 10% (income group 10 on the right-hand side) only make around 25% of their trips locally. But do they find what they need within their 15-minute area?
In all three urban areas, 15-minute usage decreases sharply with income. In New York, residents of the neighborhoods in the poorest 10% of the population (income group 1 on the left-hand side of the graph) make about 60% of their trips within 15-minute areas, while residents of the richest 10% (income group 10 on the right-hand side) only make around 25% of their trips locally.
Source: The 15-Minute City Quantified Using Mobility Data
Strategies aligned with 15-minute-city principles are already being implemented by a variety of cities with different urban forms
The role of government policies becomes crucial in addressing these challenges. Existing 15-minute-city implementations around the world — Barcelona, Bogotá, Buenos Aires, Melbourne, Milan, Paris and Portland — highlight some good practices. For instance, reframing schools as “capitals” within each neighborhood to serve more functions other than just childhood education – such as leisure and sports activities – can strengthen local diversity. As such, the 15-minute city would “not confine us to our neighborhoods or restrict our ability to travel” but simply make it “more possible and pleasant to meet more of your day-to-day needs”(2). On the topic of equitable development, anti-displacement action plans informed by input from residents can help realize 15- to 20-minute neighborhoods while ensuring equitable development.
The concept can bring environmental improvements to urban residents’ daily lives
Although urban planners in favor of the 15-minute city contend that the carbon footprint of cities can be lowered through this approach, there is no evidence yet that this would be the universal result of implementation of this policy. However, the environmental benefits can be numerous and go beyond greenhouse gas emissions. The concept emphasizes the resort to nature-based solutions such as parks, green roofs, green walls, blue infrastructure and permeable pavements to help reduce the heat island phenomena and flooding, and improve livability and physical and mental health(7). For instance, the adoption of porous bricks and porous concrete could lower pavement surface temperatures by 12°C and 20°C respectively, and the air temperature by up to 1°C(8).
The 15-minute city model is not a “one-size-fits-all” concept
By putting people’s needs at the forefront of planning decisions, the emphasis is no longer placed on mobility devices or travel speed but rather on accessibility and quality of life. However, not all cities and geographies can apply the 15-minute-city model in the same way, which shows the necessity to tailor the concept to their culture and circumstances.
(1) Urban Resilience and Urban Sustainability under Climate Change
(2) C40Cities’ Benchmark: 15-minute Cities
(3) Freedom of Mobility Forum – 29 March 2023 Debate Replay
(4) 15-Minute Cities: Debunking the Myths
(5) Eurostat - Passenger mobility statistics
(6) National Bureau of Economic Research Paper on Quantifying 15-Minute City
(7) United Nations Framework Convention on Climate Change on the 15-minute city
(8) World Economic Forum on cooling down urban heat islands