Highway Drainage ~ the stability of a highway or road relies on
two factors †
1. Strength and durability of upper surface- Strength and durability of subgrade which is the subsoil on
which the highway construction is laid.
The above can be adversely affected by water therefore it may be
necessary to install two drainage systems. One system (subsoil
drainage) to reduce the flow of subsoil water through the subgrade
under the highway construction and a system of surface water
drainage.
Road Drainage