3500 x 5250 px | 29,6 x 44,5 cm | 11,7 x 17,5 inches | 300dpi
Data acquisizione:
1 marzo 2010
Altre informazioni:
A very important feature of road construction is drainage. New roads include designed drainage systems intended to remove water efficiently from the surface of the highway to provide a safe passage for all vehicles and pedestrians.Older roads may have less sophisticated drainage, but all have features designed to take the water away from the road surface. It is necessary to clean and maintain these drainage provisions so that they can work properly. Problems can occur even when drainage provisions are clean and well maintained. Flooded and waterlogged roads occur when the amount of water arriving on the road is greater than the capacity of the drainage facilities that take it away. Exceptional rainfall, a road being in a low lying area, changes in 'run off' from nearby fields and rivers overflowing are some situations that can lead to the road flooding or being waterlogged even when drains are in good working order. Material carried into the drains by floods can also lead to them becoming blocked. Drainage grills and gratings (e.g. on gullies) can become blocked very quickly when materials like mud are deposited on the road or when there is a heavy fall of leaves. If a flooded road is caused by a ruptured water main the water company will be responsible for repairing the damage. Water is directed to drains by the road profile. Puddles (ponding) tend to occur if there is a depression in the road. This can sometimes be resolved where necessary by local patching of the road surface.
