The UK’s National Highways is trialing biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More in a major infrastructure project to explore sustainable construction methods. In collaboration with Kier and TerrAffix, the A417 Missing Link project in Gloucestershire has incorporated biochar—produced via pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More from vegetation cleared on-site—as both a waste-reduction and carbon mitigation strategy.

So far, 5 tonnes of biochar have been generated, yielding a carbon dioxide savings of 13 tonnes. Rather than transporting biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More offsite, pyrolysis was conducted directly at the construction area, reducing logistics emissions and contributing to circular resource use.

The biochar is being deployed in several ways: to support tree growth in landscaping efforts, as a filtration medium to capture microplastics from road runoff, and in the construction of a green bridge that aids water retention. These applications aim to enhance biodiversity, improve soil quality, and boost water management across the project site.

This initiative is co-funded through National Highways’ Environmental and Wellbeing Designated Fund, which supports innovation in infrastructure that reduces environmental impact. The project is part of a broader effort by National Highways to achieve net zero and improve environmental outcomes by rethinking material use in construction.

If successful, this trial could serve as a scalable model for incorporating biochar into other highway schemes across the UK, demonstrating how existing waste materials can be transformed into high-value construction inputs with both ecological and structural benefits.