[Talk-us] musings on TIGER tags

Dave Hansen dave at sr71.net
Tue Nov 23 15:44:05 GMT 2010


On Tue, 2010-11-23 at 05:24 -0500, Nathan Edgars II wrote:
> tiger:cfcc: "census feature class codes used to differentiate feature
> types"; describes the importance (generally primary=U.S. Highway,
> secondary=state highway) and type of road
> Accuracy: low. Alignments of main routes through towns almost never
> take the proper turns. Bridges and tunnels are often way too long.
> Usefulness: nil. We have other tags for this that get updated and corrected.
> 
> tiger:county: the county in which the feature lies
> Accuracy: high, though may have issues right at county lines.
> Usefulness: not sure. How much is is_in used on roads worldwide? Could
> be calculated from county polygons (if TIGER's polygons are imported
> for all states).

I added this later in the import, mostly to make the import easier.
There were a few counties that I had to go back, blow away later, and
reload.  This was invaluable for that.

> tiger:source, tiger:upload_uuid: appears to have been added by the upload bot
> Usefulness: low to nil. A source=TIGER shapefiles etc. would seem to
> be just as useful.

tiger:upload_uuid: was added so that I could differentiate different
runs of the conversion software.  Basically, I could tell if it was me,
or someone else doing the upload.  There were a few people who jumped
the gun and uploaded the same data as me, and this helped me figure out
if it was a bug in the upload scripts or a person doing it.

-- Dave




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