FM Conway and National Highways Deliver Landmark Low-Carbon M4 Resurfacing Scheme

FM Conway and National Highways have completed a pioneering low-carbon resurfacing project on the M4, demonstrating how alternative fuels, electric construction equipment and sustainable materials can significantly reduce emissions during major highway maintenance works.

The project, carried out between Junctions 15 and 16 of the motorway, is believed to be the first scheme of its kind on the UK's strategic road network and included the debut use of JCB's hydrogen-powered 3CX backhoe loader on a National Highways project.

Designed to showcase how emerging technologies can transform road construction, the scheme achieved a 50% reduction in carbon emissions compared with a conventional resurfacing approach, saving approximately 630 tonnes of CO2e.

Testing New Technologies on a Major Motorway

The M4 was selected as an ideal location for the trial due to its strategic importance and high traffic volumes, with more than 130,000 vehicles using the route every day.

Over a six-week period, contractors resurfaced the carriageway using approximately 11,000 tonnes of low-carbon materials while integrating a range of alternative-fuel and electric-powered construction equipment.

The project brought together several innovative technologies, including JCB's hydrogen-powered 3CX backhoe loader, Sany's electric planer and electric 4.5-tonne roller. Equipment was transported to site using Volvo's fully electric 42-tonne lorry, helping to reduce emissions beyond the construction process itself.

Planning for the project also included the provision of temporary hydrogen refuelling and electric charging infrastructure to support the specialist plant throughout the works.

Collaboration Drives Carbon Reduction

The scheme was supported through National Highways' Low Carbon Demonstrator Fund and delivered through close collaboration between contractors, equipment manufacturers and project stakeholders.

FM Conway Framework Delivery Manager Andy Weymouth said the project's success demonstrated the value of industry-wide cooperation.

“Delivering this scheme on time and to such a high standard was only possible through genuine collaboration with our partners – we all played a vital role. It took belief in a shared goal and a healthy dose of commitment to integrate the use of these new technologies effectively.”

He added that the project had established a new benchmark for future highway schemes.

“By working together, we overcame challenges and set a new benchmark for how sustainable road construction can be achieved on the national strategic network. This scheme is proof that when we unite expertise and resources, we can accelerate the transition to greener infrastructure and deliver real impact.”

Supporting the Road to Net Zero

National Highways says the project forms part of its wider strategy to reduce carbon emissions associated with road maintenance and infrastructure delivery.

Angela Halliwell, Head of Carbon and Air Quality at National Highways, said the organisation is committed to helping innovative technologies move from trial phases into mainstream use.

“We’re committed to cutting carbon from road maintenance and are proud to support the acceleration of new low-carbon technologies, helping bold projects like this become a reality.”

She added that the project provides valuable operational insights for future schemes.

“This isn’t just about testing ideas, but generating real-world learning that can drive wider adoption and help make our network one of the greenest in the world.”

Emissions Reduced at Every Stage

According to the project team, carbon savings were achieved throughout the entire construction process.

From the use of hydrogen and electric machinery, to the transportation of equipment and the adoption of lower-carbon materials and paving methods, every stage of the scheme was designed to minimise environmental impact.

The successful delivery of the M4 resurfacing project is expected to provide a blueprint for future low-carbon maintenance schemes across the UK's strategic road network, helping to accelerate the adoption of cleaner technologies and support the transport sector's wider decarbonisation ambitions.