👉 A subpavement is a type of pavement that is located below the surface of a road, typically between 30 and 45 inches (76 to 120 cm) in depth. Subpavements are often used for roads and highways to provide additional protection from rainwater runoff or for parking spaces. They can also be used as an alternative to pavements on some types of roads where a traditional one is not feasible due to the steepness of the terrain,
