With 70% of people living in cities and a growing preference for ageing in place, how can the 15-minute city support older adults? What urban planning strategies best address mobility, accessibility and inclusion as societies age?

The 15-minute city is designed to provide easy access to all essential services within a 15-minute walk or bike ride. This means closer access to healthcare, shops, green spaces and social activities, reducing the need for long commutes, which are essential as mobility and balance decline with age. Beyond this physical proximity, the 15-minute city also aims to develop cities that promote solidarity and sociability, as well as health and wellbeing at all ages and stages of life. 

Inclusive urban planning strategies aim to facilitate the use and enjoyment of public spaces by everyone, especially those who are unfortunately often excluded from them: the elderly, people with disabilities, women and children. This is reflected in urban planning that includes wide and accessible pavements, benches for resting, shaded and humid areas, safe pedestrian crossings and age-friendly public transport.

While the 15-minute city prioritises walkability, many older adults will still need car access for the last 100–200 metres. How can urban planning address this mobility gap while maintaining accessibility and inclusion for ageing populations? 

From my point of view, there are several ways to meet this challenge. 

The first and most obvious is to increase the density of the public transport network so that the bus stop or metro station is close enough to the home, and the second is to provide a proximity service with drop-off points and reserved parking spaces. In France, for example, it is compulsory to reserve 2% of parking spaces for people with reduced mobility, and these must be located no more than 200 metres from the public facility. 

The third, more general one, is to adapt the housing stock of each city to its demographic evolution, so that older adults can benefit from specific and personalised services to facilitate their daily life. 

The fourth could be to imagine a service system based on electric shuttles or small autonomous vehicles to transport older adults for the last few metres. The aim is to combine proximity with flexible and gentle mobility solutions.

With creativity and the necessity of demographic change, I'm sure that together we will find satisfactory solutions for inclusive and sustainable cities.

We are truly curious to hear how you managed to convince Paris Mayor Anne Hidalgo and her team to commit to such a transformative and bold change in urban planning? What challenges did you face in persuading both local governments and citizens to embrace this shift?

When we met, the Mayor of Paris had already embarked on a courageous and positive journey of urban transformation. It wasn't me who convinced her to embark on the 15-minute city journey: it was the concept and its benefits! Indeed, in a context of environmental and social crisis, the demonstration of the tangible benefits of the 15-minute city, such as reducing pollution, improving quality of life and revitalising neighbourhoods, made the adoption of this solution a natural one.

What's more, I explained that the concept is well suited to the French capital, which is historically organised into neighbourhoods and has an efficient public transport network. Challenges included resistance to change and the need to prove that this model could be adapted to the suburban context of Paris. Transparency, communication and citizen involvement were essential to overcome these obstacles.

In your book The 15-Minute City: A Solution to Saving Our Time and Our Planet, you highlight cities such as Busan and Utrecht, embracing the 15-minute city concept in unique ways. What lessons can other cities take from these examples to adapt the concept to their own needs?

Firstly, these two cities reflect the adaptability and flexibility of the concept. Indeed, it has been successfully adopted by a giant Asian tech city of 3.7 million inhabitants such as Busan, as well as by the historic Dutch city of Utrecht, while also being applied in the French capital. It shows that each city can implement the concept effectively, taking into account its own needs, historical structures and resources. However, both cities have the same goals: a happier, healthier, greener city. 

In Busan, we can highlight the clarity of the strategy and its effectiveness. A specific organisation has been set up to manage the transformation, including a dedicated urban planning department with 50 staff and a consistent budget that allows for effective selection of pilot sites for pilot projects. In addition, Busan has been very creative in its mechanisms for citizen participation. They organised an open recruitment process to select 15 representatives for a dedicated citizens group on the 15-minute city transformation. The city also made a public call for the selection of the four preliminary pilot projects. They invented the concept of the '15-minute life card', so that residents can check what facilities or community programmes they can enjoy or get involved with near their homes. 

While Busan focuses more on design transformation, Utrecht has a global and practical vision that involves changing the structure of the city over the next 20 years. The spatial strategy aims to develop a more polycentric city, towards a 10-minute city. Utrecht reminds us of the importance of public transport networks by building a ring that connects its nodes under the motto "less space to move (car, roads...), more space to live and enjoy the city". I also recognise that Utrecht's strategy could be a great lesson for demographically growing cities: they decided to create several "centre hubs", recognising that the centre of Utrecht couldn't centralise all the facilities, green spaces, people or businesses.

What’s next for the 15-minute city? As more cities adopt and adapt the concept, how do you see it evolving to address new challenges like climate resilience, ageing populations and AI-driven urban planning?

Even though the concept has gained global popularity and interest on all continents, its implementation needs to be pursued. Indeed, urban transformation is a long-term process and so is the full implementation of 15-minute cities.

The Global Observatory of Sustainable Proximities that we have set up with the ETI Chair, UN Habitat, the C40 and the CGLU already allows us to monitor the implementation of the concept around the world. We'll be able to follow the main trends, innovations and developments of the concept as society changes. I'm quite confident in each city's ability to adapt and innovate to address age-related issues, especially in the face of demographic ageing in the west. Similarly, as in all areas, AI will obviously be part of the game - and it already is in urban transformation, as observed and demonstrated by the Urban AI Think Tank.