I am looking for automatic clean-up in the master database. Something that runs daily without user-intervention. There are actually lots of stuff that can be deleted automatically. Another example is roundabouts that are also flagged as being oneway. That is not needed and only adds to the size of the OSM files.
Hm. I’m not sure if we really want to do all this completely automatically.
For example, some one-node-ways still contain tags and/or history, which may be reconstructed by experienced mappers. On the other hand, we also have editors that create completely useless (tagless, v1) one-node-ways under some circumstances. But I’d guess that it would make more sense to invest some development time to fix the programms that create the bogus data in the first place. (fix the causes not the symptoms ;))
An additional oneway=yes on a roundabout is indeed superfluous, but it doesn’t hurt anybody and is technically not an error, thus nothing that has to be corrected.