Future cities

The world’s cities are changing. Paris’s Champs-Élysées, one of the most gridlocked roads in the world, is going to become a giant garden. Barcelona has closed off its oldest quarters to cars. And now Milan is on the path to becoming the world’s first 15-minute city (read on to find out what that means).

It seems the pandemic, for some, became a moment to reimagine how we see the future of our oldest cities. Why? Well, there was a small exodus out of our urban spaces during the pandemic. It was the slightest of pauses in the net migration from rural to urban areas that has taken place for decades. Those who could afford to leave left. For those who remained, the lockdowns and restricted movement shone a harsh light on most cities’ biggest flaws: clogged roads, polluted air and a dearth of green, communal spaces.

Now, it seems that pause has inspired the world’s urban planners to rethink how cities around the world can evolve to take a different course. At this fork in the road, here’s how our cities could change course after the pandemic. An idea that’s catching on in capitals around the world is the 15-minute city. This changes the city from a dense centre with surrounding suburbs into a series of hubs within which are shopping and entertainment facilities. None of these hubs is more than a 15-minute walk or cycle from where people live, and many people may live close to more than one hub.

The 15-minute city idea comes from Colombian academic Carlos Moreno, a professor at the Sorbonne University in Paris, and has caught the attention of Paris’s mayor, Anne Hidalgo. In the French capital, the 60km of temporary cycle lanes opened in the city during the pandemic are being made permanent, with more lanes planned for the future.

Creating 15-minute cities relies on new infrastructure, however, to allow people to walk and cycle safely to their destinations, and this can create problems. “A complicated, fast-moving system where 70 million people all, at the same time, understand, agree and accept the rules is not going to happen,” says Dr Ian Walker, professor of environmental psychology at the University of Surrey.

“It’s far better to have a system where it doesn’t matter whether you agree with the rules or not, it’s still safe. An extreme example is that pedestrians can’t go on the motorway, so drivers can’t hit them there. You can start to do things like that in towns if you have a segregated cycle infrastructure, or better still, a segregated driving infrastructure that keeps the drivers safely out of the way of everybody else.”

The future goals of the Paris plan echo Walker’s sentiments. Enough segregated cycle lanes are being created so that they can be used for most bike journeys of a kilometre or so, while the main junctions that feed traffic into the centre from the Boulevard Périphérique are being made safer for cyclists coming from the suburbs. A huge number of metal arches for chaining bikes to during the day are also expected to appear on the city’s streets, along with 50,000 additional cycle parking spaces in car parks and outside housing developments.

Moreno’s 15-minute city concept won the 2021 Obel Award, an international prize to honour outstanding architectural contributions to human development. The award’s jury recognised the benefits of the 15-minute concept, releasing a statement that said, “The 15-minute city is an intuitive concept and has the capacity to deliver tangible change in people’s lives. For these reasons, it has proven easy to translate into political programmes and policies that transform cities.”

And it’s not just Paris. There has been interest in the 15-minute concept from Latin America, while Moreno has been giving presentations on his ideas in China. Limited trials have also begun in cities such as Houston, Milan, Brussels, Valencia, Chengdu and Melbourne. The C40 Cities, a global network of large cities committed to addressing climate change, embraced the 15-minute city framework in 2020 as part of the Agenda for a Green and Just Recovery.

Science Focus