CNN
—
With space in our cities at a premium, and a majority of the world’s population expected to live in urban areas within the next few decades, there’s less room for trial-and-error when it comes to urban planning – with decisions made today having critical impacts on the future.
But what if there was a way to test and analyze different scenarios first, before ever breaking ground? That’s the thinking behind “digital twins” that are being made of cities all over the world, including Shanghai, New York, Singapore and Helsinki.
Digital twins elevate traditional 3D city models to new possibilities, says Anders Logg, a professor of computational mathematics and director of the Digital Twin Cities Centre at Chalmers University of Technology in Sweden. Using real-time data and artificial intelligence, digital twins become virtual, living mirrors of their physical counterparts – providing opportunities to simulate everything from infrastructure and construction to traffic patterns and energy consumption.
Guallart Architects
The United Nations
predicts that by 2050, nearly 70% of the world's population will live in cities. To address the increase in urban populations, architects and designers have come up with innovative solutions to make future cities smarter and more sustainable.
Barcelona-based
Guallart Architects has designed a "self-sufficient city" for Xiong'An New Area, 130 km from Beijing. The 5-million-person city, shown in this rendering, would be powered by clean energy and have a circular economy -- where waste is recycled, and resources are used for as long as possible.
Scroll through to see more innovative designs for future cities.
Guallart Architects
Xiong'An New Area, China - The "self-sufficient city" won a competition in August hosted by the local government. It asked for post-Covid city designs for Xiong'An New Area that can be used as a model for different cities around the world. The buildings in this concept would be constructed from timber and are designed to use 80% less energy than traditional buildings, by utilizing solar panels, natural ventilation, and green roofs for insulation.
Stefano Boeri Architetti
Smart Forest City, Mexico - Italian architects Stefano Boeri Architetti designed this
"Forest City" for 130,000 inhabitants in Cancun, Mexico. In its plans the city is surrounded by a ring of solar panels and fields for agriculture, which would be irrigated by a water channel connected by an underwater pipe.
The Big Picture
Smart Forest City, Mexico - The city is designed to have 400 hectares of green space, with 7.5 million plants, 260,000 of which would be trees; that would give more than 2 trees per inhabitant. The architects say the city will absorb 116,000 tons of carbon dioxide per year.
LucianR and Bjarke Ingels Group
AI CITY, China - Not an entire city, but still impressive -- Bjarke Ingels Group has designed a high-tech campus for technology company Terminus Group, in China. Located in Chongqing, known as the "mountain city," AI CITY is designed to be operated by artificial intelligence. A smart system of e-bikes, robotic vehicles, and self-driving cars will run throughout the campus.
LucianR and Bjarke Ingels Group
AI CITY, China - Each courtyard in AI CITY will be programmed to host public activities such as sporting events, art exhibitions, and product fairs. The location, between mountains, allows clouds to shield buildings from the sun and there will also be overhanging roofs to protect public areas from the weather.
Courtesy BCDA
New Clark City, Philippines - In 2018, work began on a new city in the Philippines that is intended to be pollution-free and resilient to natural disasters.
New Clark City is still being constructed, about 100 kilometers north of the capital, Manila.
Courtesy BCDA
New Clark City, Philippines - New Clark City is being built as a "back-up" city from where government offices can still function should capital city Manila succumb to a
natural disaster such as an earthquake, typhoon, or flooding. Plans to make the city pollution-free include using green energy and constructing buildings that consume little energy. The first phase of development is
estimated to be complete in 2022.
NBBJ
Net City, China - A design for an entirely car-free city-within-a-city was unveiled by technology giant Tencent earlier this year. Due to be built in the city of Shenzhen, "Net City" will cover 2 million square meters,
equivalent to the size of Monaco.
NBBJ
Net City, China - The city will be built on a stretch of reclaimed land by Pearl River and will be connected to the rest of Shenzhen by road bridges, ferries, and the city's subway system. The developer, American firm NBBJ, says it will accommodate 80,000 people and take around seven years to complete.
Courtesy City of Helsinki
Kalasatama, Finland - Kalasatama is a
smart city being built from scratch on the outskirts of Helsinki, Finland. Developers say the city is due for completion in 2035 and residents will gain
an extra hour of free time every day from improved traffic flow, spaces for flexible working and smart services for grocery shopping.
SAMI HALINEN/AFP/Getty Images
Kalasatama, Finland - Engineers have designed a
vacuum waste system for the city, where people simply take their trash to a port and it gets sucked to an underground disposal center.
courtesy The Sustainable City
The Sustainable City, Dubai - This futuristic "city" has already been built. The 5-million-square-foot
Sustainable City in Dubai is designed to consume zero net energy, and has the potential to go off-grid.
courtesy The Sustainable City
The Sustainable City, Dubai - The Sustainable City has 500 homes, all powered by
solar panels. All water is recycled on site, there are no cars, and the complex grows its own vegetables in 11 biome greenhouses.
Tatu City Ltd
Tatu City, Kenya - Work has began on Tatu City, a mixed-use development in Kenya. Designed for more than 150,000 residents, it's the work of property developer Rendeavour. The 5,000-acre development includes schools, homes, sports facilities and green spaces.
Tatu City Ltd
Tatu City, Kenya - It aims to be a new urban center outside the capital Nairobi. To attract companies to set up there, the city has a special economic status providing lower business taxes. The developer says it expects the city to be
operational in 18 months.
CourtesyEko Atlantic
Eko Atlantic, Nigeria - Eko Atlantic is an ambitious multi-billion-dollar project that aims to transform Lagos, Nigeria's most populous city. Its creators want it to become the country's new financial hub -- bringing in 150,000 commuters every day.
Courtesy Eko Atlantic
Eko Atlantic, Nigeria - Eko Atlantic is being constructed on 10 square kilometers of land reclaimed from the Atlantic Ocean, as shown in this satellite image. The developers say a sea wall will protect Eko and nearby Victoria Island from
coastal erosion and storm surges, but critics claim the wall could
worsen conditions for
neighboring areas.
KONZA TECHNOLOGY CITY
Konza City, Kenya - As part of the Kenyan government's Vision 2030 project, Konza Technological City, located 60km outside Nairobi, has been dubbed the "Silicon Savanna." Spread across 5,000 acres, Konza aims to be a center of technology and innovation, as well as provide new homes.
SHOP Architect
Konza City, Kenya - Progress on the development has been slow, and concerns have been raised over its ability to attract investors. But in 2019
Reuters reported that Kenya had secured 67.5 billion shillings ($620 million) in funding from China, partly to build a data center for Konza, and that Huawei would work on the project.
Foster + Partners
Amaravati, India - The city of Amaravati in the southern state of Andhra Pradesh, India, is being built with the goal of becoming one of the
most sustainable cities in the world. At least 60% of the city will be covered in greenery or water, and its
estimated completion date is 2025.
Foster + Partners
Amaravati, India - Solar energy will power every building in Amaravati, while the transport system will include electric cars and water taxis. This is a rendering of the government complex, which will be a focal point in the city. British architects Foster + Partners are leading the project.
Chattanooga, a city of roughly 180,000 people, is nestled in foothills of the Appalachian Mountains, situated almost equidistant from the larger cities of Atlanta, Georgia, to the south and Nashville, Tennessee to the north. While larger urban areas typically get the most attention for their digital twin projects, Chattanooga is a strong test case for the US because its smaller size allows it to be more agile, says Kevin Comstock, consultant with KCI Technologies and former Smart City director for Chattanooga.
The city of Chattanooga and its various collaborators, including Oak Ridge National Laboratory and the University of Tennessee at Chattanooga, have tackled individual issues and areas by creating digital twin projects.
View this interactive content on CNN.com
The first, called “CTwin,” focused on one of the city’s major roadways to examine mobility-related energy use by building a digital representation of traffic signal infrastructure, says Comstock. Another ongoing project uses sensors and laser imaging at intersections to monitor pedestrian movements and compare it to vehicle traffic, in the interest of safety.
“If we know where pedestrians are in the intersection, and we know where cars are in the intersection, we can begin to mimic ‘near-miss’ activity,” Comstock says, by tracking pedestrians and bicyclists who alter their course to avoid cars.
Related: Are microcars the smaller, green future of urban driving?
Unlike actual accidents, those near misses aren’t usually reported. Collecting data on them would provide more accurate information on how safe an intersection is, says Comstock, enabling him to figure out how to resolve issues.
Seoul Robotics
In partnership with software company Seoul Robotics and UT Chattanooga, the city installed laser imaging technology at two busy intersections. The paths of pedestrians (green), vehicles (red), and bicyles (yellow) are tracked to register near misses and inform safety upgrades.
Can this be scaled up for larger cities? “Bigger cities have bigger problems,” says Dr. Ville Lehtola, assistant professor at the University of Twente in the Netherlands. “But it’s also some of the same problems experienced by smaller cities … so if you do the planning well, there will be less risks and the actual operation costs of construction and other operations will be cheaper. Doing better planning pays off.”
Lehtola is a former city councilor in Espoo, Finland, just outside of Helsinki. He says when a new metro line was proposed, Espoo first digitized the planning of the operations and construction. The digital twin can reveal what the finished job will look like, Lehtola says, “so you could show (the public) for example, if there’s some construction work or land development taking place, what is the outcome, how it will look, and then also get more precision on the estimates on the benefits and useability and added value of different projects.”
Logg says there are two fundamental questions to answer when creating digital twin cities: “What is analyzed to fit the current state of the city?” and “how can we predict how the city will behave?”
He points to Gothenburg, Sweden, which has taken data from sources including regular street maps to generate its digital twin. “From the data you can add things like park benches, the atmosphere, clouds, (and) water,” Logg says, and then use that raw data to create a visual model of how a new building would impact wind patterns, for example, or even potential pitfalls lurking underground.
“(Gothenburg) is built on clay, so it becomes very important to model the behavior of the clay,” he says. “What happens if you start a new, big infrastructure project? Will there be any potential risk of digging or building new tunnels?”
Related: Why the future of our cities might be headed underground
The key to success is what Logg calls “data sustainability” – the frequent, real-time updates feeding into the digital twin to keep pace with the constant evolution of the physical city. Otherwise, he says, the digital twin model “becomes stale.”
View this interactive content on CNN.com
Globally, investment in digital twins is already starting to pay off. A 2021 report by global tech firm ABI Research estimates cities will save $280 billion by 2030 “by using digital twins for more efficient urban planning.” According to another report from accounting and consulting firm PwC, digital twins can also help with sustainability efforts, one of the original aims of the “smart city” movement.
More data points are becoming available to inform the models, with sources including autonomous cars, delivery drones, and construction equipment outfitted with smart sensors, Lehtola says. As the technological possibilities increase, so do the challenges, especially with regards to gathering, storing and protecting that much data, he adds.
Digital Twin Cities Centre
This digital twin shows simulated pollution levels to measure air quality in Gothenburg. A higher density of particles corresponds to higher pollution levels.
Breaking various stakeholders from their individual “silos,” he says, is also important, so the data can be shared and make all facets of city planning more efficient.
The technical challenges are considerable, agrees Logg, because cities are extremely complex systems. But, he adds, “those are challenges that we are used to as researchers and developers.”
Logg sees a future where everything from building maintenance and new construction to roads and traffic signals will be “integrated and connected,” allowing city planners to make decisions that will still make sense decades down the line.
Digital twins “will be everywhere,” he says, “(as) the system that answers all your questions about future plans.”