[Talk-us] Karlruhe Scheme addressing ways from 2009 TIGER data

David ``Smith'' vidthekid at gmail.com
Wed Nov 25 06:34:12 GMT 2009


On Sat, Nov 14, 2009 at 1:21 PM, Apollinaris Schoell <aschoell at gmail.com> wrote:
> forget the technical aspect for a minute and think about motivation,
> how a community works and all that. no one is interested to cleanup
> crap after a bad import.

That's exactly what I've been gladly doing around Ohio for the last
year.  Most of the fixes I've been doing were made possible by the
Yahoo! imagery, basic logic, a good understanding of American roads,
casual observation of the roads as I've driven on them anyway, and the
flawed TIGER data itself.  This would have not been possible without
the TIGER roads import.  (Granted, most of the areas in which I've
worked have had TIGER data with quite high positional accuracy.  But
that hasn't stopped me from fixing up some major roads in counties
with bad positional errors.)  That "Geocoding with TIGER" website
seems to give results about as accurate as Google* or Mapquest would
in my area, so I would welcome the import for central Ohio.  The way I
see it, the choice is between perfect data for a handful of POIs and
streets scattered around Columbus, or that *plus* average data
covering the entire region.

(*Just because Google shows parcel boundaries doesn't mean their
geocoding is that good.  They still use interpolation on most streets,
which can be off by few doors.  Considering Google just recently
switched to "government" data for their base map in the US, which has
many of the same errors OSM imported two years ago, I wouldn't be
surprised if they're already geocoding with the same TIGER data that
we're talking about here.)

> osm is open to everyone to add, change, delete everything. there is no
> technical solution to have a tag like  'tiger:reviewed = no' doing
> anything useful if mappers don't agree on the usage of it. removing it
> can mean
> - I have seen it, it's approximately in place
> - I have done a survey with GPS
> - I have verified location on Yahoo is correct
> - One of the above AND name or any other attribute is correct
> - Everything is correct and it's as if I had entered the data myself

> Everyone has different thresholds when to remove such a tag, some may

You have a bit of a point there.  The absence of the tag can be a bit
ambiguous.  I once saw "tiger_reviewed=aerial" which probably means
your third interpretation.  Maybe, rather than simply removing the
tag, people should change its value to something that describes to
what extent the feature has been reviewed.

> even some official county data is badly broken. If we start to
> accept broken imports as better than survey osm is just a me to thing
> and completely useless. If anyone is interested in a me to solution
> it's called Google maps and has much better infrastructure than osm
> will ever have. they have imported all county data, park data, tiger
> data and refined with sattelite image tracing and street view data
> analysis. We can't beat them. But we can make something different with
> different value.
> the survey on ground is the strength of a community project.

I'll concede that there's a "me too" aspect involved with trying to
make OSM work for geocoding like the big names do.  But that doesn't
mean there aren't legitimate motivations.  OSM's street map is
arguably better than the big names in many places, including ones that
started with a TIGER import.  I'd love to tell people to use OSM
rather than Google, but most casual users will dismiss it if they
enter their home address and nothing comes up.  And it's my firm
belief that as more people use OSM as their primary map source, more
people will contribute to the project.  Or in another scenario, let's
say a business or organization is in an area that has changed a lot
recently.  OSM may very well have the best map of the area, but that
business can't use OSM to serve driving directions to customers unless
OSM can find the customer's starting address.  And in that case, close
is certainly better than nothing; the customer will find his way as
long as the start point is at least in the customer's neighborhood.

-- 
David "Smith"
a.k.a. Vid the Kid
a.k.a. Bír'd'in

Does this font make me look fat?




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