The 15-minute city is a popular topic these days. So here is a recent study that used GPS data from 40 million US mobile phones to estimate the percentage of consumption-related trips that actually adhere to this concept. The unsurprising result:

The overwhelming majority of Americans have never experienced anything resembling a 15-minute city. The median resident, we found, makes only 14% of their consumption trips within a 15-minute walking radius.

There is, of course, regional variation. For New York City, the data suggests that 42% of consumption-related trips occur within a 15-minute walking radius. Whereas in more sprawling cities like Atlanta, it's only 10% of trips. Again, this is not surprising. But it begs the question: What should we do?

The challenge is that 15-minute cities generally require built environments that are dense, conducive to walking, and filled with a concentration of different amenities. And this is more or less the opposite of the prototypical suburban model, where the car and single-use zoning tends to spread everything out.

The good news is that zoning is relatively easy to change. For instance, if we want to allow corner stores in our residential neighborhoods, that is a decision we can make. The greater hurdle will be transforming car-oriented communities into places where people might actually want to walk. This is much more difficult.

But of course, it too can be done.