A smart city digital twin relies on a number of layers of data that build on top of each other, layering in information about the terrain, buildings, infrastructure, mobility, and IoT devices. The digital twin uses the data generated in the virtual smart city layer to perform additional simulations; this information is fed back through the layers of the model, where it can be implemented in the physical world.

The term “digital twin” has existed since the early 2000s.  Beginning with applications in manufacturing and construction, various industries have since come to define the term in their own contexts.  According to IBM, a digital twin “is a virtual representation of a physical object or system across its lifecycle, using real-time data to enable understanding, learning and reasoning.”  Siemens adds to that the ability of a digital twin “to simulate, predict, and optimize the product and production system before investing in physical prototypes and assets.”

In the planning context, we are mainly talking about digital twins of entire cities.  According to Arup, “the promise of the city digital twin is to help provide a simulation environment, to test policy options, bring out dependencies and allow for collaboration across policy areas, whilst improving engagement with citizens and communities.”

Advancements in technology for smart cities — such as the deployment of information communication technology, sensors, and the Internet of Things — enable us to collect data about pretty much every movement, flow, or activity in a city.  The availability of this data, combined with increased computing power and artificial intelligence, can allow for the digitalization of entire cities.

The synergy of these technologies essentially leads to the development of smart city digital twins.  SCDTs can improve decision-making processes and allow for simulation and experimentation with real-time data.

Digital twin technology is relatively new to planners, as are smart city applications. But this shift signals the end of our days of limited experimentation.  Planners have the chance to go beyond simulations that can only focus on isolated questions due to limited capabilities.  While not quite mainstream yet, according to ABI Research, by 2025 more than 500 city digital twins will be deployed globally.  So, planners can expect digital replicas of entire cities and their systems sooner rather than later — that is, if they’re ready to take the first steps.


By Petra Hurtado, PhD and Alexsandra Gomex