Imagine never hitting another pothole. Researchers at the University of Surrey in England are testing a system that could make that dream real — by heating roads from underground.
The project, called Thermo-active Roads for Heat Harvesting and Pavement Temperature Regulation, embeds a network of pipes beneath road surfaces. In summer, water circulates through those pipes, pulling heat from the hot asphalt and sending it deep underground into a 100-meter borehole — that's about 328 feet down, roughly the length of a football field. When winter arrives, that stored heat flows back up through the pipes to warm the road, helping stop ice from forming.
Why does this matter? Because potholes form when water seeps into tiny cracks, freezes, expands, and breaks the road apart. It's called a freeze-thaw cycle, and it happens over and over every winter. If roads can be kept warmer, that damage never starts in the first place.
Installation has already begun in the Senate House parking lot on the university's Stag Hill campus. Phase one is underway now, and phase two begins in mid-August 2026. Researchers will use underground sensors to monitor how well the system regulates temperature over several years.
The project is led by Dr. Benyi Cao, a senior lecturer in geotechnical engineering at the University of Surrey. "Rather than reacting to potholes after they've formed, we're asking how we can prevent them in the first place," he said. "Potholes are more than an inconvenience — they are a safety hazard; they disrupt journeys and are costly to repair."
Dr. Nikolas Makasis, a lecturer in civil engineering and co-investigator on the project, said the trial will provide real-world evidence that road authorities need. "If the results are promising, road authorities will have the evidence they need to deploy this technology to create longer-lasting roads, reduce maintenance costs and make transport infrastructure more resilient to a changing climate," he said.
Unlike some experimental technologies, this one uses materials already widely available — standard plastic pipes and ordinary water pumps. That means if the trial works, scaling it up could be practical and affordable for cities and towns.
The team will also measure whether cooler pavement helps reduce air temperatures above the test section during heatwaves — a bonus benefit that could help cities cope with increasingly extreme summers.
Previous studies in Europe and the United States have explored similar ideas, but this project will be among the first to gather detailed real-world data on how geothermal roads perform in British weather conditions. If it succeeds, it could change how roads are built and maintained around the world.