In most states, municipal boundaries have been imported from TIGER data. In many of these states, no admin_level tag was used. That should be corrected (admin_level=8 for incorporated municipalities) but that's not the focus of this discussion. In the states where these boundaries were imported with admin_level=8, it appears that Census-Designated Places [1] were also included in the import, and treated the same as incorporated cities. (That's what happened in Ohio, anyway.) The wiki page [2] that lists what admin_level to use for various administrative units in different countries does not address Census-Designated Places. It does not say that CDPs should be admin_level=8, or any other value. I believe this should be addressed.
Census-Designated Places are geographical units determined by the Census Bureau to give (arbitrary) limits to otherwise-unquantifiable, informal population centers. They do not represent any real political, governmental, or administrative unit. There are no signs posted to mark the borders of a CDP. Residents of a CDP usually are not even aware of its existence, though they are certainly aware of the informal population center it's meant to represent. They really have minimal real-world significance. You may be asking yourself, 'but how can I tell if something is a CDP or an actual city?' There are a few ways. For one thing, you could look up the locality on Wikipedia. CDP boundaries typically follow only roadway centerlines and sometimes county boundaries, whereas actual corporation limits can and usually do also follow property lines and the edge of the right-of-way on one side of roads. (More correctly, CDP boundaries don't split census blocks.) Finally, the answer may lie in the tags generated by the boundary import. For example, in Ohio, there's a tag like tiger:LSAD which always ends with " CDP" if the entity is a Census-Designated Place. I suggest using admin_level=9 or admin_level=10 for CDPs. If there is agreement here, then the wiki should be so clarified. (I don't think a full-blown proposal is necessary to make a minor clarification to an existing map feature, do you?) [1] <http://en.wikipedia.org/wiki/Census-designated_place> [2] <http://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative#admin_level> -- David "Smith" a.k.a. Vid the Kid a.k.a. Bír'd'in Does this font make me look fat? _______________________________________________ Talk-us mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-us
