What is the 15-minute cities conspiracy theory?

At the Conservative Party Conference 2023, the transport secretary Mark Harper began his list of announcements with a focus on a concept called “15-minute cities”.

“First of all I am calling time on the misuse of so-called 15 minute cities,” he said. “There’s nothing wrong with making sure people can walk or cycle to the shops or school. That’s traditional town planning.

“But what is different, what is sinister, and what we shouldn’t tolerate is the idea that local councils can decide how often you go to the shops and that they ration who uses the roads and when, and they police it all with CCTV.”

In those few sentences, Harper managed to both give a fair definition of what 15-minute cities actually are, and then repeat a conspiracy theory that has no basis in fact, but has become a key strand of conspiracist thinking in the UK and beyond.

Fifteen-minute cities – and the related idea of 20-minute neighbourhoods – as defined by the academics and city planners who have proposed them, are indeed about town planning. The core idea, that everything required for daily life, such as shops or a doctor, should be a short walk or cycle from home, has been around for decades. The concept, however, was more clearly laid out in the middle of the 2010s, when an academic, Carlos Mareno, came up with a set of principles for how cities could be rebuilt to bring amenities within easy reach of their inhabitants.

The idea gained further traction in the early months of the pandemic, in part spurred by an open letter to the mayor of Barcelona. It argued that Covid-19, and the reliance on cars and public transport the pandemic had exposed, made a reorganisation along Mareno’s lines even more urgent. A paper co-authored by Mareno in 2021 laid out the claimed advantages of restructuring cities in this way:

“Within a 15-min radius, residents will manage to experience a higher quality of life as they will be required to travel less to access basic facilities such as public spaces, with increased time and opportunities to interact with other members of the community and accomplish other social functions, which are increasingly important but which have been lacking as a core function of contemporary urban planning models.”

The model has been used or proposed in cities around the world, including Edinburgh, Paris, Portland and Ottawa.