[Talk-us] CDP tagging

Richard Welty rwelty at averillpark.net
Fri Jan 9 14:40:17 UTC 2015

On 1/9/15 2:32 AM, Minh Nguyen wrote:
> Taginfo currently shows over 2,000 instances of boundary=census, both 
> for CDPs and for statistical boundaries in other countries. [1]
> I use boundary=census. If it weren't already in such wide use, I 
> would've gone with the more generic-sounding boundary=statistical, but 
> whatever. Another mapper in Ohio prefers to delete the boundary and 
> admin_level tags but leave place=locality in place. [2] IMO the 
> important thing is to remove the misleading administrative tags.
i wonder how many actual users of boundary=census there are.
if there are none, then it's a good time to consider changing it.

note that the US Census Bureau itself categorizes these as
statistical boundaries not census boundaries. arguably a
census boundary is one that they use when doing a census,
and includes both Legal boundaries and the additional
statistical boundaries.
> The TIGERcnl import apparently only brought in CDPs, but the Census 
> defines a whole hierarchy of areas, including metropolitan statistical 
> areas (MSAs), census county divisions (CCDs), and census tracts. [3] 
> If we ever attempted to map them, boundary=census and 
> boundary=statistical would be equally ambiguous and a tag similar to 
> admin_level would be required. However, there doesn't seem to have 
> been much demand for including these other Census features in OSM. 
> (For that matter, if TIGERcnl had left out CDPs, I would've preferred 
> to seem them mapped as POIs at centroids rather than as areas. Even 
> where the CDP name is widely used, the boundary is less clear-cut than 
> a city limit.)
there are people who use these boundaries today out there, but
they are not expecting to get them from OSM and they probably
shouldn't be getting them from OSM. the statistical boundaries
are subject to change. there are substantial differences between
the CDPs from the 2008 import and the CDPs in TIGER2014.

i think CDP boundaries are very clear cut, but they morph
frequently, have no legal standing, and don't necessarily
correspond to what local residents think.


rwelty at averillpark.net
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