Simulating city systems

Richard Bradley | 26 Feb 2015 | Comments

Concept to reality

Urbanisation is increasingly highlighting how a city’s citizens and their environment are connected. There is also no doubt that a wide variety of technologies are converging to provide intelligent mobility tools and smart city services that enable citizens to optimise their time and resources. (A good example is the advanced personal journey planner, or ‘journey angel’, that connects an individual’s calendar held on a mobile device with smart ticketing, reserving a parking space, booking a vehicle in a car share scheme, controlling home heating, etc.)

But how do we go from such conceptual personal tools to real connected city services? How do we provide city governors the confidence to invest in innovative solutions, with their inherent risk, which might have only been piloted in a few cities around the world? Providing evidence for future city systems might be easy in computer games such as SimCity but building robust business cases for what will be major investments needs greater rigour.

Current techniques

So, are current modelling and appraisal techniques up to the task? With a less connected society probably yes and current guidance-led business cases provide compelling evidence for treasurers and commercial investors. But current approaches have struggled to deal with interactions between just two domains, a good example being the time and resource required to model the interaction between transport and the environment. If we add in other domains such as energy and utilities, and even health and crime, plus start to think about the complex interactions with personal activity, and the many choices and unexplored benefits likely to be available, there can be little doubt that a major re-think is required.

Furthermore, existing techniques focus on aggregations of people and their activities, or small scale micro-simulations. They certainly don’t consider how the many choices available to a citizen might be influencing their behaviour, and the opportunities that this presents to service and utility providers to optimise and ‘load-balance’ demand with capacity, and for the best overall benefit to society, the economy and the environment.

Models and data

At this point it would be very interesting, at least for me, to dive deeply into detail as to how we might address this issue. However, when I resurface my message would always be the same and that is we need greater data and model interoperability if we are to be more agile and achieve full city simulations. This will not be easy but we can start thinking about manageable building blocks and the ‘glue’ provided by an open digital object model, which provides a standard interface to the many different objects featured in the city environment. Certain technologies have successfully implemented strong object models, for example the UK Department for Transport Urban Traffic Management Control programme for the development of a more open approach to Intelligent Transport Systems, and participants in the Internet of Things who are working hard to improve interoperability with initiatives such as HyperCat catalogues. But this does not go far enough to simulate an entire city with enough rigour for major business case analysis, and we need to look for an entire architecture solution.

Learning from others

Can we learn from other industries? The global defence industry had a similar problem with interoperability in the 90’s. The US defence industry therefore developed High Level Architecture (HLA) to improve system simulations, including for example war game simulators. Over twenty years the HLA has evolved and has been adopted around the world, and within other industries like gaming and space. The UK defence industry developed a number of separate HLA based object models that eventually converged to the Defence Object Model (DOM), a standard now enforced by the Department for Defence and managed by the industry led DOM Management Group.

What this means for simulating city systems

And HLA might be the saviour for simulating city systems. The prerequisite will be the open HLA object model, and this needs to be a key industry led initiative as we move forwards. With objects described in a consistent manner, the HLA computer city simulations can interact (that is to communicate data and synchronize actions) with each other, regardless of platform. Domain modelling experts can then ‘plug & play’ their HLA compatible systems, and ‘publish’ objects to, and ‘subscribe’ to objects on, the HLA simulations.

This will take time but, through a clear strategy, and with more and more simulators added to the HLA, the city systems can interact on an open and accessible platform that is truly a ‘system of systems’. Initial applications will explore contemporary and innovative modelling techniques across multiple domains, and for the first time allow holistic city scale business cases to be prepared. Enhancements will include reductions in simulation run times for use in real-time applications, and simulated data feeds will be replaced by real data feeds, thus creating a simulator for control rooms. With further speed enhancements, through techniques like ‘statistical emulators’, the HLA system will then be used for ‘near future’ forecasts to show operators the benefits of different ‘city settings’ for the next hour, guiding the operator’s choice with locally calibrated citizen orientated performance indicators estimated by the system.

So, watch this space as the modelling and appraisal communities collaboratively explore the exciting possibilities for simulating city systems. Success will be measured by the ability of analysts to present persuasive business cases for intelligent mobility and smart city services to hard pushed investors, city planners and public representatives.

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