Roads are a means by which we transport essential goods, visit our relatives, and increasingly facilitate the passage of green transport such as zero emission vehicles and active, shared or public transport options.
Undeniably, constructing and maintaining roads is carbon-intensive and energy-hungry, calling for large quantities of materials to be mined, manufactured, transported and placed. But can anything be done about this? Is it possible to create a ‘green road’?
Frameworks for carbon measurement and sustainability in road projects
The need for a more sustainable approach to road projects is increasingly being integrated into policy and legislation, embedded into business cases, and expected by communities as a component of social and environmental licence. Transport for New South Wales (TfNSW) recently announcing a Net Zero and Climate Change Policy which legislates targets for operational and embodied emissions.
The challenge of accurately measuring and actioning these commitments is sizeable, and will require learnings from both local and global examples. The National Highways Net Zero Carbon Plan in the UK, for which WSP was lead advisor is a good place to start. TfNSW is partnering with National Highways to share best practice and accelerate progress.
“The simple reality is that there is no net zero Australia without net zero roads. Transport agencies are all facing the same challenges in a safety critical industry. So it makes every sense to collaborate, share learnings and work together to make faster progress together” says David Symons, Director, Sustainability and Climate Change, WSP in the UK.
For transport agencies and planners to make informed decisions in balancing infrastructure needs with reducing carbon emissions, calculating a project’s carbon footprint early and valuing carbon appropriately are integral to success. WSP has recently been supporting Austroads on the Transport Agency Emission Reduction Opportunities project, developing Decarbonisation Decision Making Guidance incorporating assessment of whole of life carbon and cost-effectiveness, among other criteria.
PAS2080, the carbon management standard for buildings and infrastructure is an emerging international standard for carbon management in infrastructure and buildings. WSP worked with UK National Highways to achieve accreditation for PAS2080 in 2023 and some government agencies in Australia are beginning to also mandate this, along with Infrastructure Sustainability ratings which have seen growing adoption in recent years.
WSP has also developed the Carbon Zero framework, which our UK team is using to assist clients to make informed decisions considering the whole of life carbon impacts in early transport planning and strategic options assessments.
Consider carbon emissions at a transport system level
Before road projects are planned, leaders must ask whether they are necessary at all or indeed whether construction will support, or harm net zero progress. Alternatives to new infrastructure such as adjustments to traffic flow, tolls, mode shift or intelligent transport systems, public transport or active travel approaches could meet the need. This goes to the heart of PAS2080 which right from the start challenges roads authorities to think at the whole transport system level. And to question whether a new road or rail is genuinely the best way to meet a transport need.
If new infrastructure is required, the approach should consider how to make new assets more resilient and Future ReadyTM, minimising the need to build more later.
Applying a circular economy approach to road design and construction
A circular economy is based on the principles of designing out waste and pollution, keeping products and materials in use and regenerating natural systems. This approach holds promise for delivering more sustainable road projects, as it can reduce the carbon-intensive task of creating and transporting new materials but the approach requires consideration at every stage.