Paving the way to low carbon highways

A project to resurface a stretch of road in East Anglia – using recycled materials and electric machinery – is smashing low carbon targets.

National Highways tasked us, as its contractors, and WSP to deliver resurfacing of the A47 between Acle and Great Yarmouth, Norfolk, in a low carbon way.  

The result is a new structural layer of the road that's made from more than 90 per cent recycled materials. Typically, pavement layers use much less recycled or reclaimed asphalt content.  

With our recycling plant close to site, the project is predicted to save 400 tonnes of CO₂ on what would previously have been used. This is the equivalent carbon usage to filling over 1,000 Olympic sized swimming pools or powering 142 average households for a year.

Alice Grandidge, Project Manager for the scheme at National Highways, said: “We know that good quality roads are important to the millions of drivers that use our network each day. This scheme presented the ideal opportunity to resurface a road effectively but in a low carbon way – from the materials we use, where we sourced it from, how we mixed it and when we work on it. All these aspects combined together save carbon compared to a traditional approach to a road resurfacing scheme – it makes it one of the greenest major road resurfacing and is a major step towards carbon zero highways.”

Scott Cooper, Managing Director of Contracting, said: “This scheme is a great example of the effectiveness of supply chain collaboration in driving carbon reduction measures.  

“The change in design specification to use evoBuild foamed asphalt resulted in a dramatic increase in recycled content and provided substantial savings in CO₂ emissions compared with using hot mix asphalt as its production requires significantly less energy.  

“The addition of the extensive use of electrified plant demonstrated what the future of road laying could look like. The project is an excellent example of sustainable highway construction in practice.”

Dermott Doyle, Technical Director at WSP commented: "Delivering infrastructure that balances operational excellence with low carbon impact is a key priority for WSP. On the A47 project, we worked closely with National Highways and Heidelberg Materials to design a major pavement intervention that maximises recycled content and reduces carbon emissions, demonstrating how sustainable practices can be integrated into everyday road construction."

evoBuild foamed asphalt is a cold recycling bound material (CRBM), which is a sustainable paving material made from recycling existing road materials, such as asphalt and concrete. The process takes the "old" material, crushes it into aggregate, injects with air and water, and then produces a new foamed bitumen. The result is a sustainable, durable, weather resistant material, offering an environmentally friendly alternative to traditional road construction materials.  

Additionally, a low-carbon recycling plant was used close to the A47 road so that helped save carbon due to the short distance from the plant to where the road is being resurfaced. Electrified plant machinery, such as pavers and rollers were used, along with low carbon transport such as hydrogen low loaders. 

A47 low carbon construction – key facts and figures: 

• Projected carbon saving exceeding 400 tonnes of CO₂.
• Increasing the use of recycled materials by more than 13,500 tonnes.
• Providing a textbook example of the circular economy in practice each shift.
• Recycling 2,400 tonnes of tar-bound material, preventing its disposal in specialist landfill sites.
• Eliminating the need for virgin aggregate in large volumes, especially critical in a region with limited local geological availability.
• Cold mix recycling plant situated close to site (eight miles away) reducing transport distances and associated carbon (16 miles closer than asphalt supply plant).
• Work was carried out overnight between May and November 2025.