TripleS wrote:Eh? We need a gap in the white line to allow water to drain away?
Best wishes all,
Dave.
Modern edge lines are often ribbed or raised. The purpose of this is to cause an increase in tyre noise when a vehicle wanders over them thus waking sleepy truckers(and others) up and keeping them on the road.
The raised profile creates a dam that can cause the depth of surface water on the road to increase; providing a gap helps to reduce spray and prevent aquaplaning. It is surprisingly effective. On such roads you can (in very wet weather) actually see the surface water forming mini rivers as the water drains through the gaps. It's all covered in the chapter of the Traffic Signs manual I posted earlier.