National Highways is trialling a carbon-negative aggregate on a stretch of motorway in Essex in the hope of reducing the carbon footprint of our roads.

According to the Asphalt Industry Alliance, asphalt roads account for over 95% of all UK roads, with 25 million tonnes produced nationally each year. It is also one of the largest sources of carbon emissions.

In a bid to find solutions to help reduce its carbon footprint, National Highways, the government body overseeing England’s motorways and major roads, launched a low-carbon innovation competition last summer to find next-generation construction materials to help achieve its net zero targets.

Four firms emerged as winners and received up to £80,000 each to move their products forward. Seaham-based Low Carbon Materials was the first to enter the real-world trialling stage following eight months of extensive testing against highway specifications.

Low Carbon Materials’ carbon-negative aggregate, called ACLA, acts as a permanent carbon...