In a moment of supreme foreshadowing at the start of the modern TV masterpiece Breaking Bad, Walter White – both hero and villain of the piece – tells his class: ‘Chemistry is the study of matter, but I prefer to see it as the study of change.'

In his speech at the Transport Technology Forum this year, head of digital twins at the Department for Transport (DfT), George Economides, made a similar observation about his area of expertise. The hope is that digital twins foreshadow ‘about £2bn worth of benefit, not counting existing digital twins such as TfL's, over a decade'. (So not that different to Walter White's income, perhaps?)

Digital twins are based on a two-way relationship: the asset informs the twin and the twin informs the asset, producing ‘a functional output'.

As Mr Economides said, 'if the asset does not change significantly, you can just have a model, you can get all the insights that you ever need'; therefore, a digital twin ‘is really about understanding and responding to change'.

He linked three types of change to digital twins: short-term, long-term and systems change or ‘fundamental change of what transport means', as he put it, either from supply side innovations or demand side cultural shifts, such as online shopping or working from home.

The DfT has identified what it sees as the main benefits from digital twin dynamic modelling, as Mr Economides explains: ‘First, improving the flow across the transport mode. This is a better balance in the network between demand and supply, as well as reducing the friction. The second is a better response to planned and unplanned events, ranging from maintenance to crisis. The third is better collaboration with other sectors, be that energy, manufacturing, or housing.'

It can also help enable the ‘deployment of new technologies, such as self-driving vehicles'.

Theory into practice

For the last five years, the DfT has been working with the national digital twin programme - part of the Department for Business and Trade - to enable the metadata and the architecture to support digital twinning: ‘Everything is open, everything is published in order to link data between different sectors.'

This cross-departmental working has been focused on not just producing consistent data but also ‘the tools to bring data together between different sectors, with consistency on entity, time, and space'. In transport, this would mean ‘a user is a user, is a user, no matter if there's a plane, train or bus', Mr Economides said.

He added that the department hopes to soon publish work that allows different data sets to be linked together, including those from energy and water. 

He also highlighted that Whitehall might be ‘a bit naive here', but the aim is for companies, organisations and local authorities to make business cases on their own and take that forward: ‘But we have to recognise that known externalities may need extra support'.

Making change happen

To help provide this support, the DfT is also carrying out work in various areas, and on the various types of change, including decarbonisation, crisis response and whole lifecycle efficiency and resilience.

The tackle short-term change in the dynamic model, the DfT is developing a crisis response and resilience digital twin, ‘so we can be better prepared for domestic incidents, and work across government, and with local authorities'.

Another use case is focused on the long-term of infrastructure management and resilience: ‘We wanted to take a whole-life approach. The question was, if we need to look at an asset, that would be a bridge or road, do we know what information we need to make the right interventions after that time, throughout this lifecycle? And what we found was a very fragmented picture.'

As a result, it is working with Mott MacDonald as the DfT's ‘Futures advisor' as well as 38 other organisations across the private sector, public authorities and academic sector ‘to put together the first list of information requirements for whole lifecycle efficiency and resilience of built assets'.

For the third strand of digital twinning, the changing nature of transport, primary research has been conducted.

Partnering with Treasury, DfT recruited 3.5,000 people, over six months, who downloaded an app on their phone to record travel insights such as origin, destination and mode of transport.

‘We could see how different demographics changed behaviour according to events, like Storm Darragh [2004], or according to policy. We've made versions of this data set anonymised and publicly available for anyone to use. In the department, we have used it already for policy evaluation, for structure development, and we're seeing how we can support agent-based modelling and social behaviour research.'

So if you thought humans were not part of the digital twin system, think again. As we say in transport, ‘all change'.