The EU and individual European states have set ambitious sustainability targets for transport, including decarbonisation targets, sustainable development, and biodiversity conservation. To add to the challenge, much of Europe’s transport infrastructure is decades old and in need of upgrading. Funding is constrained, the prices of labour and materials have increased significantly, and there are materials shortages in certain areas. So, how do those in the transport sector help address these challenges?
The EU has set legally binding targets for achieving net zero by 2050 for all sectors, including transport, with an interim target for a 55% reduction in GHG emissions by 2030 . Key actions for achieving these targets revolve around zero-emission vehicles, including HGVs, along with the supporting charging/refuelling infrastructure and modal shift of freight to rail and inland waterways .
Whilst the EU has no specific targets regarding carbon emissions from road construction, other European countries do have them, such as the UK’s 2050 net zero target, from which National Highways (responsible for England’s strategic road network) has set targets for net zero from maintenance and construction by 2040 for materials including cement, steel and asphalt, compared to 2020 levels, with interim targets for 2030 and 2035. Sweden, too, has plans to reduce emissions from ground transport by 70% by 2030 compared to 2010 levels. Other countries are also investigating circular economy principles and aligning their strategies with the EU Green Deal objectives.
Achieving the net-zero targets would be challenging enough, but at the same time, transport budgets are constrained, and national road authorities must contend with keeping high availability on an ageing infrastructure asset. For example, recently, the M48 Severn Bridge, built in the 1960s, has been closed to heavy vehicles due to the condition of the main cables. There are various other examples in the UK and across Europe of similar interventions on ageing structures. To add to this, supply chain pressures following the pandemic and Russia’s subsequent invasion of Ukraine led to significant rises in the cost of materials, whilst wages also increased due to the high levels of inflation. This has further impacted constrained budgets.
As if this weren’t enough, climate change and the threat of more extreme weather mean that these ageing assets now need to be upgraded to increase resilience.
Whilst some infrastructure owners might despair, the transport industry continues to innovate. In recent years, there have been advances in monitoring techniques for infrastructure assets, including robotic and drone inspections, advanced imaging and LiDAR, and the addition of sensors monitoring performance. The use of sensors to continually monitor asset performance is particularly advantageous. Firstly, it increases safety by early warning of defects that may occur between periodic monitoring assessments, or that might not be obvious by visual inspection. Secondly, early monitoring of defects or weaknesses might allow for preventative maintenance or at least interventions or repairs to prevent a small issue from becoming a major issue requiring more costly interventions. Finally, the most sustainable asset is one that has already been constructed; continuous asset monitoring can give confidence to extend asset life and delay or potentially avoid replacement.
Whilst there is a cost in installing sensor equipment and enhanced monitoring of critical assets, this should be seen as an investment that could have a significant return, by early intervention, preventing more costly repairs, confidence to extend asset life and targeted use of limited budget resources.
Beyond monitoring of existing structures, there are interventions in construction and maintenance. Examples of this include self-healing asphalt and concrete materials, where cracks are sealed automatically by healing agents contained in capsules or tubes that release when exposed to water. This can extend the life of newly built assets, saving money in the long term. Another life extension maintenance being trialled is the addition of steel wool to asphalt, which, when heated by induction, causes the asphalt to soften and flow, sealing micro-cracks.
There are also ongoing trials using graphene added to asphalt, which are reported to increase asphalt durability and resistance to rutting, extending asset life and lowering whole life costs. Graphene is also being trialled as an admixture to concrete again improving strength and performance, leading to longer-lasting structures. A further benefit of adding graphene reinforcement to concrete is that less cement can be used to achieve the same strength, significantly reducing CO2 emissions. Further research in these areas is identified in FEHRL’s new SERRP VIII document – SERRP VIII: A Strategic Approach to European Road Research.
As well as new materials, innovations in construction processes also offer great potential for efficiency savings, improved construction quality and reduced emissions. Connected and Autonomous Plant (CAP) has the potential to improve construction efficiency and quality through, for example, intelligent compaction of pavement layers, ensuring even and optimised compaction, which has a huge bearing on pavement longevity. In earthworks applications, it can prevent over-digging of trenches, saving fuel and preventing rework. Some of the early gains will be from operator assistance, but in future, there is the potential for remote control of machines for worker safety and efficiency, and in some cases, fully autonomous operation, supervised by humans. Maple worked as part of an ITEN team, which undertook a market application of CAP – read more about that here.
As identified above, numerous innovations are available for use by infrastructure owners and operators. Consistent funding of research is required to ensure that new solutions and products continue to be developed. In terms of practical actions, infrastructure owners need to consider whole life costs for infrastructure rather than focus on initial cost, and view money spent on monitoring as an investment. Further, there is a need for NRAs to share some of the risks of innovation with the private sector. The private sector will invest in research and development in response to road owner requirements, but it needs some degree of assurance that innovations will be trialled and adopted. Here, it needs to be understood that there is a premium for early adoption, both in upfront cost and potential teething issues, but that over time, the prices will drop and the solutions will become more refined.
Road authorities can encourage or kill innovation depending on their procurement practices. Where procurement is very prescriptive, there is no incentive for suppliers to invest in innovation. In contrast, procurement based on outcomes naturally encourages innovation, particularly if there are incentives around savings on traditional solutions.
In other areas, road authorities could take a more proactive role in creating an environment that encourages, incentivises, and, where appropriate, requires their suppliers to adopt technology solutions. Specifically, regarding the use of CAP, the technology exists and is proven, yet hasn’t been adopted to the extent it could be. There are various reasons for this, explored in the report referenced above; one reason is caution on the side of contractors who are comfortable with pricing for jobs using conventional equipment and potentially a lack of an incentive on their part and the part of plant hire companies to spend less time undertaking construction and maintenance works.
It is clear that many technological solutions already exist – and more are emerging – that can address the identified challenges. The challenge now is for all stakeholders to collaborate in creating the right environment, procurement frameworks, and skillsets needed to unlock their full potential.
