A cutting almost always creates a problem with water that seeps into the layer works of the road. A cut-off trench was dug around the foot of the hill to accommodate for a sub-soil drainage system consisting of bidim A4, 110mm drainage pipes and 19mm stone. This drainage system prevents water running into the layer works of the road that can lead to deformation of the road.
The bidim used in this project was produced using
49 232 recycled cooldrink bottles.