Time to maintain tunnels 2026
The Centre for Underground Construction (COB) welcomed more than forty professionals from thirteen European countries on 24 and 25 June for the two-day workshop Time to Maintain Tunnels. Railway managers and national road authorities came together to share knowledge on one of the biggest infrastructure challenges of this decade: the renovation of ageing tunnels.
In virtually all participating countries, a significant renovation wave is imminent in the coming years: tunnels built in the 1970s and 1980s are approaching the end of their technical service life. In preparation for the workshop, twelve interviews were conducted with fourteen experts from eight countries. Notably, there are at least as many similarities between road and rail tunnels as there are differences — ranging from staff shortages to political pressure. Steve Phillips, Chair of the European platform of national road authorities (CEDR): “It was very good and useful to have asset managers from both rail and road together to discuss the challenges of ageing infrastructure.”
Closing Tunnels is easier said than done
A central dilemma: tunnels can hardly be closed for extended periods, yet large-scale renovations require exactly that. Experiences from the United Kingdom illustrate the impact: a renovation carried out purely in night-time windows took four years; with a few weekend closures the same work was completed in eighteen months. Traffic and environment management is one of the largest cost items, and those costs rise sharply with short, fragmented closures. Without political and public support, this remains a persistent bottleneck.
European directive, national implementation
All countries base their tunnel legislation on the European Tunnel Directive, but implementation varies considerably. A striking example: in most countries the relevant ministry is the competent authority, whereas in the Netherlands this role falls to municipalities. Johan Naber, specialist in electrotechnical systems at Rijkswaterstaat: “Having just one competent authority is definitely an advantage.”
More complex technology, shorter service life
Modern tunnel systems are becoming increasingly sophisticated, yet the service life of equipment has actually shortened. This conflicts with the frequency of major maintenance overhauls. Participants agreed to carry out further research into simplification and established that lifecycle thinking in many countries is still insufficiently embedded in the design phase. Bertil van de Kant, System Manager Civil Engineering at ProRail: “Adding more technology to a tunnel may help to get a tunnel open sooner, but afterwards that technology also needs to be maintained.”
Risks, contracts and people
On risk assessment the working group was unanimous: quantitative risk analysis (QRA) must be supplemented with qualitative assessment. The models are often complex, lack transparency and have inherent limitations. It was agreed to carry out a comparative study of the models used in the various countries. Arild Petter Søvik, tunnel expert and director of the Norwegian Tunneling Network: “It is important to be transparent about the limitations of risk analyses as well.”
Experiences with contract forms such as DBFM and PPP vary. In Belgium, DBFM was discussed as a concrete turning point in relation to the Vierarmentunnel and the Rupeltunnel. “DBFM can be applied to renovation projects, but you need to think carefully about how,” said Kris van Boven, Director of Tunnels at the Flemish Roads and Traffic Agency.
An observation from the Austrian perspective stood out: Thomas Moser, asset manager at ASFINAG: “Tolled tunnels are often better maintained.” A structured revenue stream thus helps to reserve funds for maintenance.
A third bottleneck is the growing shortage of qualified personnel. For roles such as tunnel safety officer or asset manager, there is virtually no standardised training programme. COB presented an e-learning programme as a first step and is working to strengthen the connection between experienced and less experienced tunnel professionals.
Shared urgency, shared responsibility
During the two days, collaboration was lively and productive. Karin de Haas, Director of COB, noticed the energy in the room: “I didn’t even have to announce that the second workshop session was about to begin — everyone was already hard at work.” The morning of the second day was dedicated to the winners of the CEDR Call Tunnels. Two parties are focusing on (A) data-driven asset management and (B) OTO. They used the occasion to gather requirements and, above all, to gain a thorough understanding of the real needs of tunnel managers. The final event was a visit to the new traffic control centre of the City of Amsterdam — a complex project with many phases, special attention for the Human Factor and an impressive result. Here too, many questions were asked, comparisons made and discussions held.
The two-day event concluded with a serious wish list for further investigation: can tunnel systems be simplified? Should we set up a comparative study of risk models? Can we make costs transparent and suitable for benchmarking? And above all: continue building a European network of experienced experts, policymakers and young professionals to help develop the right competencies.
The overarching message was clear: the renovation challenge is large, urgent and cross-border. No country needs to reinvent the wheel. Check the complete newsletter.
Are you a tunnel manager, tunnel safety officer or director responsible for tunnels, and are you not yet part of our international group? You can join by contacting ellen.vaneijk@cob.nl.
Partnering for the preservation of tunnels in Europe
Key issues
For the majority of European countries, the Refurbishment and Renewal of Critical Objects (tunnels and bridges) is high on the political and implementation agenda. In April 2024 the Declaration of Dublin was signed by the GB members to encourage a process of collaboration and common research on these two critical nodes. What are the key issues?
- The task is huge and acute. If these critical nodes fail, entire regions and corridors will fail, with major economic and social damage.
- The available resources are insufficient. Not only in terms of finances, but also available capacities at both clients and contractors. The feasibility of the task must be more effective and smarter.
- The costs for management and maintenance are significantly higher after renovation and existing budgets and organisations are not set up for this.
- Actual residual life is unknown in many aspects; unexpected failure is lurking.
- The social requirements (cyber security, sustainability, new fuels) make the manager uncertain: is my infrastructure object future proof after renovation?
Steps towards a transnational tunnel programme
Based on the key issues as indicated above, a document is designed with the help of CEDR members. This document, Time to maintain tunnels, presents the practical translation of the Declaration of Dublin for Tunnels. It has been built from input from national and local tunnel owners/managers from Austria, Belgium-Flanders, CERN (Europe), Denmark, Ireland, Italy, The Netherlands, Norway, Poland, Portugal, Slovenia, Sweden and United Kingdom in both national workshops and meetings, further detailed in the Invited sessions on the 16th of October 2024 in Antwerp, following the Beyond a tunnel vision conference. As such, this document is a stepping stone in a process of building a transnational network for effective knowledge exchange and knowledge development on the challenges of refurbishment and renewal of ageing tunnels in Europe.
Are you interested in Time to maintain tunnels? Please send an email to Ellen.vaneijk@cob.nl
