ROAD-AI, a Challenge for more sustainable, safer and more resilient road infrastructure

The road network is one of the most important public assets. The French State is actually responsible for almost 21,000 km of roads, all of which need to be maintained, developed, replaced and preserved. If not kept in good condition, these roads could see both their asset value and use value diminish, with all the major economic consequences that would entail.

Behind all of this are the road operators, like Cerema, the Centre for Studies and Expertise on Risks, the Environment, Mobility and Urban Planning, which promotes integrated management of infrastructure assets (IMIA), among other things. The aim of this approach is to reconcile the long-term challenges with short-term constraints and operational rationales so that the State can have transport infrastructure and services that are more sustainable, safer and more resilient.

Today, however, the infrastructure is under great strain because of climate change. The increasing incidence of extreme phenomena, such as floods, ground movements, mudslides, etc. is not without consequence for our roads. In addition, the ways in which the infrastructure is used are also changing, whether in terms of traffic density or type (more heavy vehicles). As for road users, they are becoming more and more concerned about safety and comfort issues relating to road use, as well as the environmental challenges involved in building and maintaining the road infrastructure.

These are the issues that led Cerema to invite Inria to set up a partnership in which they could share their expertise – namely, Cerema’s technical skills and Inria’s scientific skills in the digital domain. The aim is to advance the management of infrastructure assets for the benefit of road operators, by overcoming the scientific and technical obstacles currently standing in Cerema's way.

“For Cerema, the idea is to better understand road infrastructure defects, especially those caused by the cold, rain and ice, but also by heavy-vehicle traffic, in order to better anticipate and prioritise maintenance works,” explains Nathalie Mitton, joint coordinator of the Inria teams involved in the ROAD-AI Challenge.

Under this partnership, which was formalised on 24 June 2021 with the signing of a framework agreement, a Challenge, called ROAD-AI, was created and launched on 1 July 2021, with four business objectives set by Cerema: build a dynamic “digital twin” of the road; develop “laws” of behaviour for roads and other structures based on data obtained from surface surveys and inspections, sensors and environmental data; devise the concept of system-wide “connected” bridges and tunnels; and establish methods for strategically planning investments and maintenance (predictive, prescriptive and then autonomous).

“The very essence of a Challenge is to allow research teams to work in ways other than the traditional scientific silo. And what was interesting about this particular partnership is that it ensures that teams that wouldn’t normally work together can do so, to meet the business objectives more effectively,” explains Christophe Biernacki, joint coordinator of the Inria teams involved in the ROAD-AI Challenge.

Four business objectives divided into three multidisciplinary research streams, based on the cross-cutting technical building blocks identified by Inria and Cerema during their preliminary discussions:

1. Data capture via sensors and drones 
2. Data recovery using 3D modelling
3. Survival analysis, anomaly detection based on processing versatile data

“Initially, there was a great deal of discussion around how to convert Cerema's business issues in order to interpret them as scientific obstacles. This initial phase has been long but essential to be able to enter a maturation phase and, from there, get to the heart of the challenge; it’s the scientific road map,” suggests Christophe Biernacki.

Six Inria research teams, which took on the Challenge following a call for projects, have been assigned to the different workstreams, according to the subject of their research: ACENTAURI, COATI and FUN to workstream one, TITANE to workstream two, and MODAL and STATIFY to workstream three. Several Cerema teams have also been assigned to each category.

Recruitment (of engineers, doctoral and post-doctoral students) for the Challenge will be conducted systematically and officially, and jointly supervised by the members of the Cerema and Inria teams, so that different stakeholders can work more closely together, whether their expertise lies in business or science.

It is then time for the second phase, during which the scientific part will take precedence. The three workstreams will progress differently, depending on the issues being addressed, but coordination meetings for the project as a whole will take place at least once a year (in addition to standard meetings organised for each stream), in order to review how the partnership is progressing. The final phase of the project, which will last almost two years, will focus on evaluating the scientific results with Cerema engineers, so that they are implemented right at the core of the centre's activities.

Apart from the ROAD-AI Challenge, the ultimate goal of which is to develop asset strategies for road managers once the outcomes have been operationalised in engineering terms, the framework agreement concluded between Cerema and Inria is the first step towards potentially more comprehensive cooperation between the two bodies.

Cerema is active in several other fields, such as marine safety, construction, mobility and even the environment, that could also be the subject of joint research efforts. “The framework agreement is not specific to the Challenge; it encompasses the Challenge as one of the possible activities, but Cerema is willing to be involved in something broader, potentially other activities,” says Christophe Biernacki.

Meanwhile, the Institute is delighted with the initial exchanges of expertise with Cerema and the particular way it works, i.e. encouraging the onset of dialogue between the different stakeholders: “Cerema is committed to research and understands the challenges faced by public bodies, while also having an important business obligation. For Inria, working alongside another public body, in such a blended way, means being able to share expertise and illuminating points of view,” concludes Nathalie Mitton.