Wiki has descriptions for the surface types, https://wiki.openstreetmap.org/wiki/Key:surface gravel seems to be general term that includes compacted gravel, I had to look up difference between dirt, ground and unpaved without text descriptions from the wiki that would have been impossible.
Wiki has descriptions for the surface types, https://wiki.openstreetmap.org/wiki/Key:surface gravel seems to be general term that includes compacted gravel, I had to look up difference between dirt, ground and unpaved without text descriptions from the wiki that would have been impossible.