[Imports-us] Tiger Realingment

[Eric Fischer]

Right, I still never got the script to the point where the results seemed
good enough to go ahead and import. I was able to improve the process
somewhat by using the TIGER node IDs and block edges to find equivalents
for some of the roads whose IDs had changed, but some areas are still very
messy.

My big realization was that even when the TLIDs are stable, sometimes the
endpoints are connected differently in new TIGER than in old, so it's not
really possible to do the whole thing through node relocations—to avoid
contradictions, sometimes the ways will also have to be changed to connect
them differently than they were connected before.

The best tool I know of right now for detecting areas where manual TIGER
cleanup would help is Martijn van Exel's TIGER Battle Grid (
http://maproulette.org/battlegrid/#10/47.4086/-121.9427), which doesn't
identify individual streets that disagree with TIGER but does show the
number of disagreements in different grid cells.

My most recent attempt in the manual tracing direction is a map of what
changed in different versions of TIGER (
http://www.mapbox.com/blog/new-in-tiger-2013/) but that just shows TIGER
changes, not which of them are already reflected in OSM. I've also been
working on one that subtracts the changes that are already in OSM (
http://www.mapbox.com/blog/openstreetmap-tiger-improvements/) but it needs
some more work before it will be good enough for a public release.

Eric


On Thu, Sep 5, 2013 at 11:30 PM, Clifford Snow <clifford at snowandsnow.us>wrote:

> Eric,
> I can't remember the end result of the proposal to run your bot to align
> roads to the new tiger data. I don't believe you ever ran your script.
>
> There is an October Editathon that would be perfect to see what we can do
> manually. We'd like to target Washington State. Is there a way to get a
> sense of where to focus our efforts? For instance, could you give us just
> Washington State to look at or is it county by county? I'm thinking that if
> you found a large number of changes in an area we could get people working
> to clean it up by comparing existing to the TIGER2013 Extended overlay as
> well as bing image.
>
> Is this something that can be done? Our alternative is to list rural
> cities and just hit them one by one. Which isn't all that bad either.
>
> --
> Clifford
>
> OpenStreetMap: Maps with a human touch
>
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