This photo is from the edge of a cycle path through an industrial estate which is currently being improved.
Motorists are discouraged from cutting the corner and driving onto the cycle path or parking on the cycle path by these large sharp edged pieces of concrete.
The corner here is necessarily of larger radius than usual, and certainly of larger radius than you find in residential areas, because there are a lot of trucks in use in the industrial estate. However, they should not drive on the cycle path.
Another view in the opposite direction.
Note that the sand eventually goes between the tiles with sort of surface.
Update 29/1/2009. There seems to be a bit of misunderstanding about the angles of things in these photos. This is far from the best junction for cyclists in this area. However, note that at the point of crossing cyclists are crossing the road at very nearly a right angle. Also note that cyclists have priority at this crossing. Drivers have to wait in both directions. The first photo shows that there is a car's length between the road and the cyclist crossing which gives a space for a car to wait to pull into or out of the road.
This picture shows a child's playground in a residential area, again protected by concrete from residents or visitors deciding to park on it. It's in the same residential area that I made a video of a few weeks ago. A very child friendly area, as Dutch residential areas are. The speed limit is always either 30 km/h (18 mph) or "walking pace" (the phrase used in the law).