The city of fifteen minutes, this is the future of the megacities

An interview with Carlo Ratti, director of the MIT Senseable City Lab

Carlo Ratti is an Italian architect, urban planner and academic. He teaches at the Massachusetts Institute of Technology in Boston where he directs the MIT Senseable City Lab. He has been featured in Wired magazine among the “50 people who will change the world.”

Professor Ratti, how will cities and especially large megacities change after Covid-19?

“To answer this question, we must first look at the experience of the past two years. At the beginning of the health emergency, as the lockdown emptied our urban streets, several experts predicted the end of cities and a mass return to the suburbs. In fact, quite the opposite has happened: the pandemic has set in motion a very strong potential for urban rebirth and innovation — the physical space version of what economist Joseph Schumpeter called “creative destruction.”

In general, the pandemic acted as an accelerator of changes already underway. In the midst of the emergency, mayors and city officials were left without “case studies,” and were therefore able to adopt an experimental, trial-and-error approach to respond to residents’ new needs. One example above all: the many “tactical urbanism” actions that — from Milan to Barcelona — have been successful in returning public space to pedestrians and cyclists.

What will happen in the future, then? No one has the magic bullet, but now that the emergency is largely over almost everywhere, I believe it is essential to continue with the experimental “creative destruction” approach I mentioned earlier. If public and private actors can continue to use the city as a testing ground for new ideas, and if residents continue to actively participate in the collective discussion about the civic future — while accepting, with the right degree of trust and patience, that by necessity some experiments will be less successful than others — I believe that our cities can indeed become more beautiful and welcoming.”


What has been the U.S. response to the pandemic to date in terms of new urban projects? Do you see any evidence of a goal of fostering new models of urban integration?

“Everywhere in the world — not just in the United States — the pandemic has highlighted new dynamics of urban segregation. The challenge now is to figure out how to counter these trends.

In particular, after so many months of working remotely during Covid-19, I believe the priority is to focus on reclaiming physical meeting spaces. The American sociologist Mark Granovetter, in an important scientific article written in the 1970s, classified our social relationships into two categories: “weak ties” between casual acquaintances and “strong ties” between family members or friends who in turn are each other’s friends. Research developed by our lab at MIT has shown that smart working, if practiced exclusively, runs the risk of relegating us to only “strong ties,” eroding our ability to understand what is different, creating dynamics of polarisation and closure with respect to novelty and confrontation with the outside world in general. Physical space, on the other hand, represents an antidote to this isolation.

This therefore means having to create offices that stimulate what the British call the “cafeteria effect” — the aggregating effect of common spaces — and that stimulate the exchange of different ideas, which of course is the basis of creative work. At the same time, it will also be necessary to rethink living spaces, which must become more flexible and accessible even for the most fragile social groups.”


The European response has been mainly directed toward the energy transition and sustainability. Is this a great opportunity to modernise the Old World?

“The challenge of decarbonisation is key, and in this many cities on the Old World, and particularly in Northern Europe, are experimenting in interesting ways. These often rely on European funds, but also individual city initiatives.

For example, in the past year, with our design firm CRA-Carlo Ratti Associati we have implemented one of the winning projects in a competition organized by the Helsinki municipality to decarbonise a neighbourhoord heating system. The project, called Hot Heart, is based on huge floating islands in the middle of the sea, which function as thermal batteries, managed by artificial intelligence systems, allowing energy from renewable sources to be stored. This goes a long way toward solving the last major obstacle to the full adoption of wind and solar: clean, inexpensive sources, but which have a major limitation because they are intermittent. In contrast, thanks to Hot Heart, the Finnish capital will divest its coal-fired power plants by 2030, developing a model that we believe can be applied by many other cities as well.”


Do the European funds allocated for post-Covid economic recovery, and I’m thinking in particular of Italy’s Recovery and Resilience Plan, take sufficient account of the need to invest in smart cities and sustainable mobility?

“It seems to me that they do, although we need to avoid fragmentation. My opinion is that an appropriate tool could be to create “digital master plans“: master plans related not so much to the built city but to its management. There would be so many challenges: from shared mobility, to the development of public platforms for data collection, to incentives for “slow” tourism that promotes both youth entrepreneurship and volunteerism and solidarity. Only with such strategies could we organically manage the post-Covid transformation.”


How important is sustainable mobility in bringing the cities of the future to life?

“It is crucial, considering the huge impact that mobility has in terms of energy consumption, pollution and traffic.

Of course, sustainable mobility must be part of a broader rethinking of urban dynamics. In this regard, a very interesting concept is the so-called “15-minute city“: an idea initially developed by French urban planner Carlos Moreno. The 15-minute city aims to reorganise physical space around the human experience of time. Each neighborhood becomes an “isochrone,” an area that can be explored in a given time, giving all residents access to their needs at a convenient walking distance.

I think this is an idea we will hear a lot about in the future, which moreover fits very well with the structure of Italian cities. A key goal to keep in mind in building the cities of the future is to remember the old adage of the great American urban planner Lewis Mumford, who farsightedly wrote, ‘Let’s forget the damn cars and build our cities for friends and lovers.”


You are chair for the World Economic Forum of the Future Council on Cities and Urbanisation. What will the cities of the future look like and what efforts should we make to modernise them?

Digital technologies have radically transformed many aspects of our lives over the past two decades: from the way we work, to the way we communicate, move and meet.

If I had to identify a specific challenge for the future, it would be to find ways in which new technologies can help us counter climate change — or at the very least, contain the negative effects that are already evident. In more philosophical terms, it is to bring together and reconcile the two great poles of the natural and the artificial, long thought of as distinct.”


Data analysis is also an increasingly popular tool in the design of major infrastructure works. How important is data collection and analysis even in the infrastructure sector?

“The collection and analysis of data from the physical space are key elements in many of our projects. With data, we can contribute to better infrastructure maintenance. Recently, with our researchers at the MIT Senseable City Lab, we conducted an experimental study on the health of bridges.  Currently, these analyses are carried out through fixed sensors directly installed on the infrastructure. Our idea was to use accelerometers that are embedded in our cell phones as a source of information: what if every motorist passing over a bridge could act as a “sentinel” of its state of maintenance? This will make it possible not only to detect bumps and potholes and traffic status, but also vibrations and any abnormal frequencies.”


You often cite Milan as a city at the forefront of this transformation. What does the Lombard capital have that can become an example in the world?

“Milan has long been a magnet for innovation that serves as a driver not only for Italy, but for Southern Europe. In the coming years, it must continue to work on its strengths in the field of services — culture, design, communication, fashion — while pushing for greater social integration.”


From your observation point at MIT Boston, what is the attitude of young college students toward sustainability issues? Have they increased their sensitivity to “green” companies?

“I believe that in terms of attention to sustainability issues, the younger generation is extraordinarily attentive, not only at MIT but in universities everywhere around the world! The cultural change has already taken place, and I think this is the best insurance for the future of our planet.”