Why is proper drainage essential in highway construction?

Proper drainage is essential in highway construction primarily to prevent water accumulation and erosion. Effective drainage systems are designed to redirect water away from the road surface, thereby reducing the risk of standing water. This is crucial because accumulated water can weaken the road structure over time, leading to potholes, cracks, and other forms of damage. Moreover, without adequate drainage, erosion can occur, undermining the roadbed and potentially causing significant structural failures. Therefore, by ensuring appropriate drainage, the longevity and safety of the highway are maintained, making it a fundamental consideration in road design and construction.