Imagine being able to observe a city through a virtual replica, simulate how a new road would affect traffic or predict changes in a neighbourhood’s energy consumption. With digital twin technology, all this becomes possible.
Digital twins are transforming the way public authorities, businesses and researchers design and manage urban environments. By combining data, artificial intelligence (AI) and simulation models, they make it possible to analyse complex scenarios before making changes in the real world.
But what is a digital twin? Discover how digital twins work along with the European Union’s initiatives to encourage its adoption.
Table of contents
Digital twin: what it is and what it means
A digital twin is a virtual representation of an object, system or physical environment powered by data that make it possible to analyse its behaviour, monitor its evolution and simulate alternative scenarios.
Unlike a simple three-dimensional (3D) model, a digital twin does more than reproduce the appearance of what it represents. It integrates information and models that help explain how the system works.
For example, a digital twin of a building can use temperature, energy-consumption and occupancy data to simulate energy-efficiency improvements.
When this technology is applied to neighbourhoods, infrastructure or entire cities, it is known as an urban digital twin or local digital twin (LDT).
How does a digital twin work?
A digital twin works by integrating a range of technologies: the Internet of Things (IoT), big data, artificial intelligence, cloud computing and simulation tools.
The process can be divided into four stages.
1. Data collection
The first stage involves gathering information about the physical environment.
IoT sensors, geographic information systems (GIS), databases and other sources can collect data on traffic, energy consumption, air quality, infrastructure and environmental conditions.
Data quality is crucial: incomplete or outdated information can undermine the reliability of simulations.
A related example from JO Group is Domus Sapiens, an HT Apps project that uses connected sensors, cloud infrastructure and harmonised data to monitor indoor environmental conditions and support predictive alerts. Although it is not presented as a digital twin, it illustrates the data integration and IoT foundations on which more complex virtual models can be built.
2. Creating the digital model
The collected data are integrated into a virtual representation of the system.
In a smart city, the model may include buildings, road networks, public spaces and energy infrastructure.
The representation may be three-dimensional, but its real value lies in the ability to connect digital elements to information and processes in the physical world.
3. Scenario analysis and simulation
Using algorithms, mathematical models and, where appropriate, AI systems, a digital twin can simulate alternative scenarios.
For example, a local authority could assess how changes to a road network would affect urban mobility before implementing them.
Simulations cannot guarantee accurate predictions, but they help compare potential outcomes and risks.
4. Decision-making support
The resulting information enables administrators and technical specialists to identify issues, compare solutions and plan interventions.
In this way, a digital twin becomes a tool for data-driven decision-making, helping to make planning more informed.
Digital twins and smart cities: 5 practical applications
The integration of digital twins and smart cities creates new opportunities for sustainable urban development.
Let’s explore 5 areas in which this technology can help improve city management.
1. Smart mobility and traffic management
An urban digital twin can simulate traffic flows, assess changes to road layouts and examine the impact of new infrastructure.
For example, before building a cycle lane or changing a junction, a local authority could compare scenarios to understand their effects on traffic circulation.
The aim? To promote more efficient, accessible and sustainable mobility.
2. Building energy efficiency
A digital twin can support energy-consumption analysis and the assessment of building refurbishment measures.
Using data on building characteristics and heating and cooling systems, it is possible to simulate different energy-efficiency strategies.
This information can help public authorities prioritise investments.
3. Environmental monitoring
Digital twin technology can be used to analyse air quality, urban temperatures and other environmental phenomena.
For example, a model could simulate how creating new green spaces would affect temperatures in a neighbourhood.
This application is particularly relevant to planning climate-change adaptation measures.
4. Urban planning and infrastructure management
The construction of new buildings, redevelopment of public spaces and development of infrastructure can be assessed through digital simulations.
Public decision-makers can therefore compare different projects and assess their potential effects on mobility, services and the environment.
Port infrastructure offers a concrete application beyond city streets. GeminiPort, a research and development project involving HT Apps within JO Group, aims to create a digital twin of a maritime port integrated with a Port Community System (PCS). Its proposed architecture combines IoT, AI and blockchain to support port logistics, monitoring, operational simulations and informed decision-making. As the project runs from May 2025 to November 2027, these are project objectives rather than completed results.
5. Risk prevention and management
A digital twin can also help analyse phenomena such as floods, heatwaves and extreme weather events.
Using simulations based on geographical data and specialised models, authorities can assess risk scenarios and plan preventive measures.
Within JO Group, SECESTA ViaSAFE offers a related example of sensor-based monitoring and predictive modelling. With PMF Research involved, the project uses near-real-time information on volcanic ash, together with atmospheric and ground-deposition models, to support safer mobility in the Catania metropolitan area. It is an example of data-driven risk management, not a project formally identified as a digital twin.
What are the benefits of digital twins for cities?
Digital twins can offer a range of benefits to public authorities, businesses and citizens.
The main benefits include:
- more informed decisions: data and simulations help assess the consequences of administrative decisions;
- resource optimisation: comparing scenarios can help identify more efficient measures;
- environmental sustainability: models make it possible to explore strategies for reducing energy consumption and emissions;
- greater urban resilience: risk analysis supports the planning of preventive measures;
- citizen participation: digital representations can make urban projects easier to understand and facilitate public consultation.
However, these benefits depend on data quality, model reliability and public authorities’ ability to use the tools correctly.
Digital twins in Europe: what is the EU Local Digital Twin Toolbox?
The spread of digital twins is also one of the drivers of Europe’s digital transformation.
To encourage the adoption of these technologies, the European Commission has supported the development of the EU Local Digital Twin Toolbox, a set of open-source tools designed to help cities and regions create, analyse and use digital urban models.
In June 2026, the completion of the Toolbox development phase and the start of its adoption by European cities were announced.
The solution includes modular components, harmonised data and algorithmic models that can be used to simulate urban mobility, climate, energy and public-space planning.
One of its most interesting features is interoperability: public authorities can use shared tools and standards without necessarily developing every component from scratch.
The initiative therefore aims to make Local Digital Twins more accessible, including to cities with limited digital resources or expertise.
Digital twins and the Citiverse: towards more participatory cities
A further development of digital twins is the Citiverse, a concept promoted by the European Commission to make digital urban environments more interactive and accessible.
While a digital twin primarily makes it possible to represent, analyse and simulate how a city functions, the Citiverse also seeks to create new ways for citizens, communities and public authorities to interact.
Through technologies such as augmented reality (AR) and virtual reality (VR), people could explore redevelopment projects before they are implemented, better understand changes to their local area and participate in decision-making processes.
Imagine, for example, being able to visit a square virtually before its renovation, examine different design options and contribute to public consultation.
Technological innovation thus also becomes an opportunity to promote more informed and engaged citizenship.
Challenges to overcome when adopting a digital twin
Despite the opportunities, adopting digital twins presents several challenges.
The first concerns data availability: information from different systems must be collected, updated and integrated.
A second consideration is skills. Developing and managing a digital twin requires expertise in modelling, data analysis, urban planning and digital technologies.
Cybersecurity, personal data protection and operating costs also require particular attention.
For this reason, building a smart city cannot depend solely on purchasing new technologies. Shared strategies, training and collaboration among public authorities, businesses, universities and research centres are essential.
JO Education and digital innovation for smart cities
Promoting collaboration among innovation stakeholders is one of the goals of JO Education, a non-profit organisation committed to spreading digital culture and developing initiatives dedicated to technological transformation.
Through Innovation Hub Catania (IHCT), JO Education supports the creation of an ecosystem in which businesses, universities, institutions and innovators can share expertise and develop new opportunities for collaboration.
In this context, technologies such as digital twins represent a valuable area of exploration for those working in urban development, sustainability and digital transformation.
Sharing expertise and fostering dialogue between research, businesses and local communities can help create the conditions for testing innovative solutions and building increasingly smart cities.
Frequently asked questions about digital twins
What is a digital twin in simple terms?
A digital twin is a virtual representation of a real-world object, building or system. It uses data and models to analyse how it works and simulate potential changes.
What is the difference between a digital twin and a simulation?
A simulation reproduces how a system behaves under specific conditions. A digital twin combines a representation of a real-world system with data and models that can be updated over time, enabling contextualised simulations and analyses.
How are digital twins used in smart cities?
In smart cities, digital twins can be used to analyse traffic, energy consumption, air quality, infrastructure and urban-planning scenarios, supporting public authorities’ decisions.
Which technologies are needed to create a digital twin?
The main technologies include IoT sensors, data-management systems, mathematical models, cloud computing, GIS tools and, for some applications, artificial intelligence and machine learning.
Can smaller municipalities use digital twins too?
Yes. Adoption depends on available resources, objectives and data. European initiatives such as the EU Local Digital Twin Toolbox are designed to facilitate access to modular, interoperable tools, including for public authorities with different levels of digital maturity.
