I think surface started as a binary paved/unpaved for roads (with paved assumed by default, and paved meaning tarmac), and has got extended to cover cobbled roads, and (subsequently) as a way of adding more info for tracks/paths.
So for most purposes, the principal distinction is between paved and not, and that can perfectly well be determined by checking for the presence of the tag, and whether it's value is "paved". There's a bit of a grey area for well-maintained unsealed paths/roads, but the binary paved=yes/no doesn't really help. I tend to use other clues - that it's got a higher road classification, or is flagged as being part of a cycle route. It wouldn't hurt if there was a value for "well-maintained unsealed", perhaps surface=graded? Richard _______________________________________________ Tagging mailing list [email protected] http://lists.openstreetmap.org/listinfo/tagging
