The organisation tasked with maintaining the nation’s motorways has confirmed plans to “accelerate” the switch to low-carbon asphalt in roadworks. Highways England says it is asking contractors to use so-called ‘warm-mix’ asphalt that emits less carbon dioxide during the production process.

The government-run organisation says all those involved in the construction and maintenance of the strategic road network – and particularly designers and main contractors – are being asked to use warm mix asphalts or WMAs. Highways England claims WMA technology makes resurfacing more efficient, with CO2 savings of up to 15 percent when compared to conventional hot-mix asphalts.

Ordinarily, typical asphalts are produced at up to 190 degrees Celsius, but WMA technology allows that temperature to be reduced by up to 40 degrees and adhesives added to the mix. That means less energy is used to make the asphalt that forms the road surface, but the performance of the surface is not compromised.

Aerial view on the new asphalt road under construction

Highways England says if all asphalt production in the UK switched to WMAs, it would save around 61,000 tonnes of CO2 a year. That’s the equivalent of cutting car journeys by around 300 million miles every 12 months.

Furthermore, the organisation claims such a move would save up to £70 million a year in increased shift outputs, while the product can also be recycled back into new asphalts, preventing waste. Yet despite the lower temperatures, WMAs can be laid using existing equipment.

Road asphalt resurfacing construction

As a result, Highways England has changed its WMA policy, which previously urged companies to apply before laying warm-mix asphalt. Now, the organisation hopes to streamline that process by urging maintenance and roadbuilding firms to use WMAs as a matter of course.

Some 250 applications had already been lodged as companies clamoured to use WMAs in projects on motorways including the M1, M5 and M6. With the new process, however, Highways England says using WMAs will become much easier and more straightforward.

“This is a big step forward for Highways England that allows us to not only achieve huge efficiency savings but also reduce carbon as we strive for net zero,” said Malcolm Dare, the executive director of commercial and procurement at Highways England. “Carbon reduction, along with ensuring our roads provide smooth, safe, and efficient journeys for motorists, are key and something we are constantly striving to improve for generations to come.

“That’s why we are altering our way of working to encourage and enable the use of warm mix asphalts as standard across the supply chain, which has efficiency, sustainability, and health and safety benefits whilst not compromising performance.”