CAPSULES THAT HELP ROADS ‘SELF-HEAL’

1

Sunflower oil capsules measuring a tenth of an inch (2.9mm) are added to asphalt

2

After years of heavy traffic, which cause cracks in the road, the capsules break open

3

The oil combines with bitumen in asphalt to make it flow better into minute cracks, plugging them within four hours before they become potholes