[Talk-ca] GeoBase and OpenStreetMap

[Dan Putler]

Hi Dave,

There is one important difference between the Canada NRN and the US
TIGER data. Specifically, the locational accuracy for the NRN is much
better than is the case with TIGER. As a result, the need to undertake a
big effort editing ways to fix their locational accuracy isn't going to
be nearly as critical (put another way, what do you trust more,
someone's Garmin eTrex or the provincial highway department's Trimble
differential gps unit?). As a result, the potential loss of information
from "forking" the data is relatively more important for the Canada NRN
then the US TIGER data. In my opinion the current US situation is
unfortunate. As a data user you have the choice of one publicly
available road network that is very good with respect to locational
accuracy (OSM), and another that has much poorer locational accuracy but
has address range and local area identifier information (TIGER) which
allows it to be used in geocoding and certain types of routing
applications (although, its locational accuracy is a problem for this).
If the TIGER TILD's had been maintained on the OSM ways life would be a
lot easier for a lot of potential users of the OSM data.

My two cents.

Dan

On Mon, 2008-12-15 at 14:32 -0800, Dave Hansen wrote:
> On Thu, 2008-12-11 at 15:02 -0500, Mepham, Michael wrote:
> > My first question has to be “Why are you doing this?”.  I have spent
> > some time looking through the OSM web site and I understand the
> > rational for building street maps where none exist or at least are not
> > generally available but that is not the case here.  I know of at least
> > two other complete downloads of the GeoBase data for redistribution
> > but still do not fully understand the reasons for replication /
> > duplication.  
> 
> The basic reason is that we need to be able to edit it.  We can't simply
> put data back into GeoBase, so we need a copy on which to work.  Is
> there a way we even could get changes back to the "owners" of the data?
> 
> I think the core of it is that OpenStreetmap isn't your normal user.  We
> don't want to just take the data and put it on a map, or figure out
> where all the residents in an area live.  One of our core goals is to be
> able to update and change the map.
> 
> > Secondly – How does this group expect maintenance to work?  When the
> > data suppliers pass updates to the GeoBase portal team and those
> > updates are made available then GeoBase and OSM will be out of sync.
> > What are the expectations on how or when they will be brought back
> > into sync?
> 
> For the US TIGER data, we are simply diverging.  There is no plan that I
> know of, and relatively little need right now, to bring things back into
> sync.  
> 
> It is just a huge problem with no easy solutions.  The easiest solution
> that I see is what we're doing now: leave the data, and let the users
> improve it, just like the rest of the world. 
> 
> These huge government databases have, in effect, been a jump start for
> OSM.  But, I'm afraid they're a one-time thing.
> 
> -- Dave
> 
> 
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-- 
Dan Putler
Sauder School of Business
University of British Columbia