how do i map a paved area

how would I tag a closed path so the renderer would recognize it as a paved area? there are 2 circumstances where i would like to use this feature. One is the circle at the end of a dead end road. The other is trail maps. I have several areas where a road gives off to a paved parking area. without a method of showing the parking area the trails seem to just start in the middle of nowhere. Not planning to show all paved areas, just those that are needed to make sense of other features.

http://wiki.openstreetmap.org/wiki/Key:area
but for your two examples, it’s probably better to use http://wiki.openstreetmap.org/wiki/Tag:highway%3Dturning_circle and http://wiki.openstreetmap.org/wiki/Tag:amenity%3Dparking .