by Susie Ruston McAleer, Mark McAleer and Pavel, Kogut (21c Consultancy Ltd)
Visualise a world in which people can rapidly and intelligently collaborate and respond to societal challenges and unlock innovation for future service needs as easily as visiting Google Maps. A world where the urban experience becomes easily understandable at the touch of a button, breaking down service silos and enabling evidence-based decisions and behaviour changes to be made collaboratively and effectively. This vision is fast becoming a reality thanks to an emerging local digital twin market, with European innovative initiatives such as Digital Urban European Twins (DUET) [L1] and COMPAIR [L2] leading the way.
Digital twins for smarter, sustainable cities
We are in the midst of a 4th revolution, the digital revolution, with new technologies changing how we live, work and spend our leisure time. Accessing government services should be no exception, but until recently the public sector struggled to keep up with the pace of change. The impact of COVID-19, however, forced many cities to reassess their operations and recognise that the adoption of new technologies and data to deliver “smarter” approaches to delivering city services is no longer a luxury but a necessity. Using integrated digital approaches to manage city operations and support evidence-based decision making, not only enables services to be delivered remotely, but can improve existing ways of doing things. As a result of the unprecedented crisis, the newly emerging concept of cloud-based, AI-enabled, local digital twins (term coined by DG Connect, 2020) has been thrown under the world’s spotlight.
Local digital twins are virtual city replicas that make it easier for anyone to visually understand the complex real-time interrelation between different urban factors such as traffic, noise and environment. In the case of European innovation project DUET, powerful analytics embedded within the digital twins integrate data silos and model the expected impacts of potential decisions across city systems, such as the knock-on effects of road closures, new housing estates, and location of transport hubs, on roads, public transport, air quality and health. The evidence-based simulations support both city managers and policy makers in working together around common scenarios to make better, cross-domain, operational decisions and longer-term policy choices whilst enhancing transparency, citizen involvement and resource optimisation .
Led by Digital Vlaanderen, the IT company for Flanders, Belgium, DUET is building a 3D regional digital twin (see Figure 1) to help predict and understand the impacts of regional mobility so policy can be implemented in a way that minimises stress on both the environment and human health. A second pilot by the City of Pilsen, Czech Republic, is using its 3D digital twin for urban planning to model and assess the predicted impact of new buildings on the local area. Improving citizen engagement in public decision making is the focus of the final pilot in the city of Athens, Greece. The digital twins plan to go live to the public this Autumn (2021).
Figure 1: Preview of DUET 3D digital twin interface on a laptop.
The shift from digitise to humanise
While great technological strides have been made in local digital twin development in the last two years, thanks to the pioneering work of DUET and other local initiatives, further societal value is still to be unlocked. As Birks, Heppenstall and Malleson  argue in their recent paper Towards the development of Societal Twins (2020) many of the current systems focus on infrastructure and not “the representations of the individual people whose actions ultimately drive the evolution of the cities they inhabit”.
Pushing the state of the art in digital transformation, Digital Vlaanderen is launching a new research project in November 2021 called COMPAIR, which places citizens not just at the centre of service delivery using digital twins but empowers them as the central protagonists in identifying and solving local air-quality problems. Introducing the concept of “citizen science” COMPAIR aims to bring social and emotional intelligence into the decision-making process. Helping policy makers to develop skills for engaging and involving citizens from all echelons of society in decision making, especially hard-to-reach citizens from lower socioeconomic status, helps to remove biases from traditional consultation methods. Participants in COMPAIR will not just be able to use DUET digital twin interfaces to view and understand urban data but they will also be able to identify the issues that affect them and their communities, collect data themselves using sensors, and be able to upload anonymised personal information such as emotions (e.g., how a space/location makes them feel, heat rate information etc). Populated with more nuanced spatio-temporal data the local digital twins can then provide a more accurate representation of the city experience for data-driven decision making and can become a true force multiplier for co-creating societal good. Cities won’t just be smart, they will be citizen driven and automatically responsive to societal needs.
With the right data, current digital twins can model and simulate whole urban systems in ways that were unimaginable only a few years ago. This new technology has the potential to become the central linchpin for administrations to efficiently leverage all its locally generated data and new technology to effectively meet public sector missions. However, to truly be a game changer and enter a new era of not just smarter, but “responsive” cities, long-term success is dependent on supplementing physical information with social and emotional data which enables local digital twins to better support the co-creation of meaningful, intelligent, data-driven urban experiences for all.
 L. Raes et al.: “DUET: A Framework for Building Secure and Trusted Digital Twins of Smart Cities”, in IEEE Internet Computing, doi: 10.1109/MIC.2021.3060962.
 D.Birks, A.Heppenstall and N.Malleson: “Towards the Development of Societal Twins”, IOS Press, ECAI (2020)
Susie Ruston McAleer
21c Consultancy Ltd, UK
+44 (0) 7949 252 141