Could geothermal roads help prevent potholes before they form? New trial aims to find out

The U.K. faces a persistent pothole problem, but researchers at the University of Surrey believe they may have a solution from beneath the road surface. Their new trial, the Thermo-active Roads for Heat Harvesting and Pavement Temperature Regulation project, investigates whether a ground-source heating and cooling system can regulate road temperatures throughout the year, making them less prone to damage and reducing the carbon footprint of highway maintenance.

The system involves embedding a network of heat-exchange pipes beneath the road surface, which absorbs heat from the asphalt during summer and stores it in a borehole 100 meters deep. In winter, the stored heat is circulated back through the pipes to warm the road surface, helping to prevent ice formation and the freeze-thaw cycles that lead to potholes.

The trial began in August 2026 at the University's Senate House parking lot on Stag Hill campus, with plans for a second phase in the coming months. Project lead Dr. Benyi Cao emphasized that the goal is to prevent potholes from forming in the first place, rather than reacting to them after they appear. He noted that the project will use mature, readily available materials, making it practical and affordable.

Previous studies have explored similar concepts, but this trial will provide real-world evidence of the technology's performance in U.K. conditions. Researchers will also measure air temperatures above the test section to determine if cooler pavement can help reduce surrounding air temperatures during extreme heat. Dr. Nikolas Makasis, a co-investigator, stated that the trial will provide valuable insights into the effectiveness of geothermal road systems, potentially leading to longer-lasting roads, reduced maintenance costs, and increased resilience to climate change.