As part of its new “superblocks” plan, Barcelona has defined several groups of 3×3 urban blocks where indoor car traffic is mostly prohibited and spaces for parks, pedestrians and cyclists are expanded. A new study explores how the same approach could be applied in cities around the world – without becoming too inconvenient for car traffic.
Urban superblocks: Modern cities face a multitude of challenges: flooding, air and noise pollution, extreme heat. For city planners, these issues raise important questions about how our cities can become more livable, sustainable and resilient to climate change.
An innovative plan is currently being rolled out in Barcelona, Spain’s second largest city. Many streets in Barcelona are laid out in a grid and, according to the plan, groups of 3×3 blocks have been merged into “superblocks”. While the streets surrounding the superblocks remain open to vehicular traffic, the streets within cannot be crossed by car and impose speed limits of only 10–20 km per hour to make it safe for pedestrians.
This transformation means that much of the space occupied by these streets can now be dedicated to walking, cycling and public transport. The plan also opens up space for new parks and green spaces, introducing biodiversity corridors that run through the city.
In the superblocks, car traffic is mostly prohibited and spaces for parks, pedestrians and cyclists are expanded.
On top of that, superblocks can act as their own independent communities: allowing residents to easily walk to local shops, schools, and restaurants, without dodging traffic or queuing at corner crosswalks.
Barcelona now has a long-term vision to introduce superblocks across the city. A 2020 study suggested that if around 500 superblocks were created, the reduction in heat and pollution experienced by local residents could increase their average life expectancy by almost 200 days.
The challenge: Despite the optimism of this vision, the plan did not come without opposition. For some residents and city planners, the concern is that the superblocks could severely disrupt car traffic. This will not only make life harder for people who have to drive, but it could also increase congestion and pollution on the streets surrounding the superblocks.
As a compromise, some city planners have proposed “miniblocks” as a potential solution. Made up of 2×2 or 1×2 groups of city blocks, miniblocks follow the same logic as superblocks, but present fewer obstacles to the car traffic that surrounds them. Still, there are concerns that miniblocks do not offer the same walkability and durability benefits as superblocks.
So far, no system has been created to weigh the pros and cons of superblock and miniblock deployments. Until now, this has made it difficult for city planners to find solutions that can appeal to everyone.
The study: In a new analysis, Sven Eggimann from Empa, Switzerland, has developed a method to assess the transformative potential of superblocks in different cities. The automated system works by taking into account how people’s ability to move around the city would change when superblocks and miniblocks are placed in different locations.
Driven by real data collected in these cities, Eggimann’s system could calculate how (mostly) banning traffic in one area affects the rest of the road network. Besides Barcelona, he also considered several other global cities, of widely varying shapes and sizes.
In Tokyo, Paris and Cairo, more than 20% of streets could be designated as superblocks.
Although Barcelona’s square road network provided an ideal model to test the superblock concept, the results showed that the idea can also be well suited to cities with very irregular road networks.
In some cities, such as Atlanta, Eggimann found that only a small percentage of streets would be suitable for placement of superblocks, before becoming very inconvenient for vehicular traffic. This was mainly due to their low population densities. In contrast, more than 40% of streets in Mexico City could be designated as superblocks, provided they are placed in appropriate locations. In cities like Tokyo, Paris and Cairo, that number was still over 20%.
Miniblocks largely followed the same pattern in Eggimann’s calculations – but in cities like London they might be much more appropriate. Here, the potential for superblocks is relatively low, as they would often be crossed by roads that are major arteries for automobile traffic. Accordingly, miniblocks could provide a well-suited compromise.
The big picture: Taken together, Eggimann’s findings provide the first detailed insight into how Barcelona’s innovative approach to urban design could be applied in cities with widely varying cultures and urban layouts – many of which will face their own set of challenges in the decades to come.
By providing city planners with helpful guidance on the realistic placement of superblocks and miniblocks, Eggimann hopes his system will enable cities around the world to become more sustainable and resilient to climate change; while becoming happier, healthier and safer places to live.
We would love to hear from you! If you have a comment about this article or have a tip for a future Freethink story, please email us at [email protected].