In a bid to prevent the development of potholes and extend the lifetime of roadways, scientists from the University of Surrey in the U.K. have proposed using geothermal energy to control the temperatures of road surfaces.

Because potholes tend to develop on roadways due to the expansion and contraction of groundwater under the pavement — specifically, the repetition of freezing and thawing that weaken the asphalt binder, otherwise known as the glue of the road surface — the Surrey team suggests incorporating ground source heat pumps into the pavement to cool roadways in the summer and warm roadways in the winter.

As such, the scientists are developing graphene-enhanced microcapsules to improve heat conduction and storage in the soil below road surfaces. Eventually, they expect to test this approach via laboratory-scale experiments, ranging from numerical modeling to full-scale field trials on U.K. roadways.

Furthermore, the Surrey team expects to build a laboratory scale model road segment featuring a heat pump in their lab for evaluating the thermal performance as well as the resilience of roadways under controlled climatic and traffic loads.

Discussing the inspiration behind the proposal, research lead, Dr. Benyi Cao from the University of Surrey explained: "So I'm thinking, we have a road here, and there's a huge amount of ground underneath the road — why don't we just use this ground itself as a collector and storage for heat in summer, and extract that heat again in winter?"

In addition to extending the lifetime of road surfaces, which typically have a roughly 20-year lifetime, this new approach promises to make roadways safer, reduce carbon emissions and lower the cost of road maintenance, the Surrey team suggested. Additionally, the geothermal energy technology could gradually be incorporated as roadways are resurfaced.