Imagining how we might actually create 15-minute cities

The idea of the #15-minute-city has become subsumed in woke politics in the UK. New research takes a step back and identifies how many global #cities have key services that are accessible and how that share could be improved.

Imagine living in a city where all the services that you needed were just five minutes from where you live. Welcome to Zurich! Researchers used open source data to measure the time it would take people to access resources and services within 10,000 cities.

The study in the journal Nature Cities in September found that compact medium-sized European cities topped the table both in terms of the time taken and the share of population that reach them within quarter of an hour. After Zurich with an average journey time of just over five minutes, Milan, Copenhagen and Dublin took the next four places in both categories.

For example in the Irish capital it would take the typical resident seven and half minutes to reach transport, healthcare, education, shops and restaurants while 99.2% of Dubliners could do that within 15 minutes The cities with the longest distances to walk and the fewest people within a 15-minute radius were in the sprawling cities of the Americas and Asia. Within the 54 cities they analysed in detail, the worst was San Antonio, Texas where the average trip to key services took over 50 minutes and fewer than 3 per cent of residents only needed 15 minutes.

When looking at large, global metropolises, Europe also topped the list with Paris, Berlin, London and Athens all in the top 15 for both time needed and share of population, with 85 per cent of residents having key services within walking distance from their homes and an average time of 10 minutes or less. If you want to check your own city, the researchers have downloaded all the data into a giant global map that can be found here with the whole world split into hexagons for each neighbourhood.

The divide between Europe on the one hand and the Americas and Asia on the other is a reflection of the design principles that led to the growth of European cities over the past millennium around walking and public transport versus the car-dependency of more modern post-wear conurbations.

The online map also shows how the central and outer central of many cities are a mass of 15-minute cities thanks to the provision of services. But move to the city edges and the distances lengthen as services are harder to find. As their map of Rome shows, there is a clear “doughnut” effect in Italy’s capital.

Rome: colour code associated with the degree of accessibility

The more depressing news is that, in the researchers’ words, only a “tiny proportion” of the cities are very well positioned to become 15-minute cities. “The disparity in the local availability of services is an additional layer of difference between cities,” they write.

This raises the question as to how city planners could bring more residents within a 15-minute zone — assuming that there is not strong local opposition to achieving that. The researchers created a mathematical method to assess the degree of change required for these urban areas to improve their accessibility. Their findings revealed stark contrasts: San Antonio would need to redistribute 80 per cent of its services and facilities to achieve equitable access for all residents, whereas Paris would only need to shift 10 per cent% of its amenities to accomplish the same goal.

They went further, to ask how many new services — places of interests (POIs) in their words — would be needed for the city to be 15-minute for at least 90 per cent of its residents. Unsurprisingly spawling cities such as Atlanta and San Antonio where 50-minute walks are standard, the cost of adding enough POIs would be prohibitive. Atlanta would need more than 15 POIs per 1,000 residents, which converts to one POI for every 64 residents.

Looking ahead, however, this research points to the importance of ensuring that services are well-located when new cities are being built — as may happen under a Labour government — or when older urban areas are regenerated. Investment in public transport can also help to shorten those journeys.

This research will hopefully inspire further investigation and prompt tangible steps in city planning and policymaking as city planners seek to live up to the goals of urban sustainability that are so often citied in the visions they set out.