Following our recent blogs on circularity and electrification, this post revisits a wider piece of work delivered with colleagues from ITEN and RDS. In 2022, we undertook a PIARC (World Road Association) special project on the Carbon Neutrality of the Road Sector. Roads are indispensable for economic activity and daily life, yet they are also a major source of emissions. Our study set out the current strategies and emerging technologies, and, crucially, how road administrations can turn ambition into tangible progress.
Net Zero vs Carbon Neutral – why the distinction matters
One of the first things we had to do in the project was clarify terminology. “Net Zero” and “Carbon Neutral” are often used interchangeably, but there is a clear distinction:
- Net Zero means reducing emissions as close to zero as possible, with any residual emissions absorbed by offsetting or technologies like carbon capture.
- Carbon Neutrality means balancing emissions through offsetting—removing CO₂ elsewhere to cancel out what’s produced.
It became quickly apparent that the project should focus on means to achieve net zero, as it is simply not possible to plant our way out of it, or wait for some silver bullet technology. There is ample evidence that carbon capture are storage is economically ineffective, as well as technically unproven.
Whilst tree planting is great for biodiversity, local air quality and ground stability, it is not an effective long-term store of carbon. Trees die, get chopped down or burned, releasing carbon into the atmosphere. That’s even before we consider how little carbon a sapling will absorb, or some of the dubious claims and lack of data associated with some schemes.
A global shift in strategies
Our survey of National Road Administrations (NRAs) found that 83% of respondents’ countries already had Net Zero targets. Regardless of whether formal policies were in place, most were implementing measures such as electrifying fleets, switching to LED lighting, and improving maintenance practices.
The picture is not uniform, with some countries ahead, and others at the start of the journey, but the direction is the same. Here, the lessons from pioneer projects can be instructive for both High Income Countries and Low and Middle Income Countries (LMICs) alike. Three examples noted in the study are as follows:
- National Highways (UK): A roadmap to Net Zero with interim dates—corporate emissions by 2030, maintenance and construction by 2040, and road users by 2050. Actions include cutting corporate emissions 75% by 2025, electrifying the fleet, planting three million trees, and publishing a blueprint for EV charging. Interim targets can help focus actions and help measure progress. 2050 can feel a long way away, but we can’t wait until the 2040s before real progress is made. Also, as of July 2nd this year, 2050 is nearer to us now than the year 2000.
- A590 reconstruction (Cumbria, UK): An £8m project rebuilt a key dual carriageway in a way that was carbon neutral by design. By collaborating early with carbon modelling experts, using recycled materials, and powering works with solar generators, the project cut emissions by 43% compared to conventional practice.
- Québec motorway junction (Canada): A C$3.7bn, six-year scheme rebuilt 145 km of lanes and added public transport and cycle infrastructure. Delivered largely under design-and-build, it showed that even mega-projects can aim for neutrality when innovation is built into the contract
Each case underlined the same lesson: large scale carbon reduction is achievable when it’s designed in from the outset.
The technical toolbox
The report examined a broad range of technical solutions, varying in maturity, carbon-saving potential, and relevance according to context. Some technologies include:
Construction and maintenance
- Prioritise maintenance over new build where possible. Prolonging asset life avoids the largest embodied emissions.
- Apply circular economy principles, using reclaimed asphalt, recycled aggregates, secondary materials, and innovative concretes.
- Use warm-mix or cold-mix asphalt in place of traditional hot-mix to cut energy demand.
- Design for low rolling resistance surfaces to reduce vehicle fuel use.
- Adopt efficient or alternative-fuel construction plant and site equipment.
Operations
- Replace conventional lighting with LEDs and source renewable electricity.
- Decarbonise road agency fleets, including heavy vehicles.
Vehicles and fuels
- Support electrification of cars and vans. This is achievable now, while for heavy goods vehicles, a mix of solutions is emerging: battery electric, hydrogen, or electric road systems.
- Encourage modal shift towards active and public transport, where the carbon savings can be vast. A 10% switch from cars to buses in the UK alone could cut 5.8 MtCO₂ annually
People and procurement
Technical measures alone are not enough. Our research emphasised two critical barriers or potential enablers:
- Workforce capability: From policymakers to contractors, carbon literacy is essential. Decarbonisation requires new skills, behaviours, and mindsets throughout the supply chain.
- Procurement power: NRAs wield huge influence through their standards and contracts. By embedding decarbonisation in specifications and tender evaluations, they can create the market conditions for innovation and low-carbon materials.
- Sharing risk: where the share of the risk is heavily skewed towards the contractor, innovation stalls. Road owners need to have a fair share of risk and reward to encourage new ways of working.
- Business models: for construction and maintenance in particular, most business models are based on a take-make-waste linear economy, with a nod towards sustainability in contracts. To embed circular economy principles requires a step change in business models, where repair, maintenance and whole life value and whole life carbon are embedded.
The challenge of evidence
Comparing “apples with apples” remains hard. Project claims vary in scope and rigour; lifecycle boundaries are sometimes unclear; data can be scarce. The report calls for better data collection, clear system boundaries, and standardised whole-life assessment so lessons are transferable and successes scalable.
A fair transition
Decarbonisation cannot be at the expense of development. For LMICs in particular, where new road construction remains essential for economic growth, strategies must strike a balance between emission cuts and mobility needs. The report stressed the importance of a “fair transition”: ensuring that climate goals do not entrench inequality or stall much-needed infrastructure.
This requires tailored approaches. What works in Norway may not fit in Nigeria. Yet the principles of efficiency, circularity, innovation, and integration with wider transport policy, apply everywhere.
Recommendations – what should road authorities do?
The report concluded with a set of recommendations:
- Develop long-term strategies now, with roadmaps and interim targets, underpinned by robust baselines of emissions.
- Prioritise reduction over offsetting—use offsetting only for residual, unavoidable emissions, and ensure that the offsetting scheme is transparent and validated.
- Invest in people—build carbon literacy and capability across the workforce and supply chain.
- Leverage procurement—embed decarbonisation in standards and contracts to drive innovation.
- Adopt whole-life analysis—ensure decisions consider total carbon impacts, not just upfront costs.
- Support evidence and knowledge sharing—collect, publish, and use reliable data on what works.
- Play an active role in collaboration—work with governments, industry, and communities to enable systemic change.
Looking ahead
The report’s findings and recommendations are only three years old and remain valid. We organised a ‘Special Session’ at the 2023 World Road Congress, where the results of the report were presented, and road agencies worldwide presented their approach to reducing carbon. Many technologies exist, more are being developed, and the policy levers and business models can be created. Now, we just need to make it happen!
At Maple Consulting, we continue to work with clients across the UK and Europe to translate these insights into practical strategies. Whether through circular economy approaches to materials, new construction processes, or adaptation of infrastructure to climate change, the goal remains the same: roads that serve society while respecting the climate.
You download a copy of the report from the World Road Association here or by email from Maple Consulting – [email protected]
