In summer, temperatures can climb very high, especially during heatwaves. You may have seen images of roads warping, buckling, or cracking due to heat. This is no exaggeration: yes, heat can indeed damage roads, and it happens more often than you might think.
Image East Cambridgeshire Police
Roads are primarily made of asphalt or concrete, two materials that react to temperature. Asphalt, for example, contains bitumen, a black petroleum-based binder. This bitumen softens as temperatures rise. When it gets extremely hot, asphalt can soften to the point of losing its shape, making it more vulnerable to repeated car or truck traffic. This can cause ruts, bumps, or even localized depressions.
Concrete, on the other hand, doesn't soften but expands when heated. This means its slabs expand slightly. If the heat is intense enough, concrete slabs no longer have enough room to expand. Result: they can buckle or even crack under the pressure, creating what are called "thermal buckles." These deformations can make a road dangerous or unusable, sometimes requiring temporary closure for repairs.
Engineers normally account for these effects when building roads. They leave gaps called "expansion joints" between concrete slabs or adjust asphalt mixtures based on regions and climates. But during exceptional heatwaves, even these precautions can prove insufficient.
These phenomena are becoming more frequent with climate change, as extreme heat events grow more numerous and intense. This is forcing many cities and countries to rethink the materials and techniques used in road construction.
So yes, heat can indeed break roads. It's a genuine technical challenge for engineers and communities. A road that melts or buckles isn't just impressive to see—it's also a hazard for users and a repair bill waiting to happen.