As Europe continues to battle an intense heatwave, images of melting roads in the United Kingdom have sparked global attention and prompted comparisons with countries like India, where summer temperatures regularly exceed 45 degrees Celsius. Despite facing even higher temperatures, Indian roads generally remain intact because they are specifically designed to withstand extreme heat.
The difference lies not in the quality of construction but in the climate conditions each country prepares for. Road engineering is tailored to local weather patterns, meaning materials that perform well in one region may struggle in another.
Why UK Roads Soften During Extreme Heat
Roads in the United Kingdom and many other European countries are primarily designed to survive freezing winters. They must endure repeated cycles of freezing and thawing, which can cause cracks and structural damage over time.
To tackle these conditions, engineers commonly use hot rolled asphalt and dense asphalt concrete both of which contain softer grades of bitumen and finer aggregates. These materials allow roads to expand and contract without cracking during cold weather, improving their durability in winter.
However, during rare periods of extreme heat, this flexibility becomes a disadvantage. When temperatures approach or exceed 40 degrees Celsius, the bitumen begins to soften, causing roads to deform under the weight of heavy traffic. This results in rutting, sinking and other surface damage.
Why Indian Roads Withstand Extreme Summers
India faces a very different climate challenge. Instead of prolonged freezing conditions, the country experiences months of scorching temperatures, intense sunlight and heavy traffic. As a result, Indian roads are built using harder grades of bitumen such as VG-30 and VG-40, which have higher viscosity and remain stable even under extreme heat.
Road construction in India also uses larger stone aggregates that improve strength and reduce the chances of roads softening or developing permanent deformations during the summer months.
These design choices ensure that roads remain durable despite repeated exposure to temperatures that frequently cross 45 degrees Celsius in many parts of the country.
Climate Determines Road Design
Experts say the contrasting performance of roads in Europe and India reflects different engineering priorities rather than differences in construction quality. European roads prioritise flexibility to survive harsh winters, while Indian roads focus on resisting prolonged heat.
As climate change increases the frequency and intensity of heatwaves across Europe, engineers may need to reconsider traditional road building materials and adopt solutions better suited for rising temperatures. The recent heatwave has highlighted how infrastructure designed for past climate conditions may require adaptation as weather extremes become more common.