The UK's pothole problem could one day be tackled from beneath the road surface, as researchers at the University of Surrey launch a pioneering trial that uses heat stored underground to keep roads cooler in summer, warmer in winter and less prone to damage.
The Thermo-active Roads for Heat Harvesting and Pavement Temperature Regulation project will test whether a ground-source heating and cooling system can regulate road temperatures throughout the year – helping roads better withstand increasingly extreme weather while reducing the carbon footprint of highway maintenance, improving safety and reducing the inconvenience of roadworks.
The system works by embedding a network of heat exchange pipes beneath the road surface, running through both the asphalt and the layers below. During summer, water circulating through the pipes absorbs heat from the asphalt and transfers it to a 100-metre-deep borehole, where it is stored underground. In winter, that heat is circulated back through the pipes to warm the road surface, helping to prevent ice from forming and reducing the freeze-thaw cycles that contribute to potholes.
Installation has already begun in the Senate House car park on the University's Stag Hill campus, with the first phase of the trial underway and the second phase starting in mid-August 2026. Once operational, researchers will monitor the system over a number of years using underground sensors to assess how effectively it regulates road temperatures.
Unlike many emerging infrastructure technologies, Surrey’s project uses mature, readily available materials, including standard plastic pipework and water circulation pumps, making future deployment both practical and affordable.
Previous studies in Europe and the United States have explored similar concepts, but Surrey's project will provide detailed real-world evidence of how the technology performs in UK conditions.
As well as monitoring the road itself, the team will measure air temperatures above the test section to investigate whether cooler pavements could also reduce surrounding air temperatures during periods of extreme heat.
The project is funded through Dr Benyi Cao's Royal Academy of Engineering Research Fellowship, with additional support from Surrey County Council's Lane Rental Scheme.
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**Notes to editors **
Filming opportunities: Journalists are invited to visit the trial site on 25–26 August 2026, while the ground is open and the heat-exchange pipes are installed. This will provide an opportunity to film the system before it is covered over. Please enquire if you would like to arrange a site visit.- A time-lapse video showing the construction and installation process will be available in early September.
- Dr Benyi Cao is available for interview; please contact
mediarelations@surrey.ac.ukto arrange. - Images are available upon request
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