Talk:TIGER fixup/County borders

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Discuss TIGER fixup/County borders here:


Easier to use JOSM validator

It is much easier to do this using the "validator" plugin and looking for duplicated nodes. Simply download along a county line and validate, then remove duplicated nodes. I will try to add this to the howto. Jumbanho 13:26, 11 August 2009 (UTC)

...although if you simply do that, then you'll still wind up with duplicate ways. Roads running along county lines tend to be in the database twice, with all their nodes duplicated and also the way itself sitting directly on top of the way from the other county. If you only fix duplicate nodes, you'll fix the routing problems, but leave behind two copies of the same way (now sharing the same set of nodes).
I was thinking of delving into the validator plugin code to try and come up with a new fixable test for the case where an entire way, and all of its nodes, are sitting on top of an identical one.
The other awkward thing is the way the validator plugin allows you to fix dupe nodes which are off the edge of your downloaded area. This doesn't actually work, and can break the data ("precondition failed" when you try to upload) ...I understand that's been fixed to give a warning now at least. So maybe a new plugin could automatically download along a county line before resolving duplication problems.
-- Harry Wood 14:43, 11 August 2009 (UTC)


duplicate ways

Hi, I'm new to this, and mostly just corrected alignment and names on a few streets near my little rural town, but I have come across the duplicate ways at county lines. So... how should we fix those? Do we essentially just delete one of the ways, and make sure any cross roads are joined at the way we don't remove? Seems like removing TIGER data would cause it to come back if there is ever another TIGER import, but I don't think copying TIGER data from one node to another along the entire way is appropriate either (and leads to duplicate tag names too). --Granack 00:32, 1 October 2009 (UTC)

Yes. It's a tricky kind of data mess to try to sort out, but if there's a road running along the county line, they you normally need to hit delete on one of the two ways, and then reconnect roads from one side again.
Don't worry about future imports. If and when such an import happens, it should (MUST) be done as an extremely carefully planned process which would either analyse existing data and apply intelligent corrections (where "intelligent" would not involve re-creating duplicated way problems) and/or operate only in areas where people have not been working on the existing data. If anyone ever screws up an area you have been working on by importing, feel free to swear at them loudly from me!
-- Harry Wood 12:54, 1 October 2009 (UTC)
Okay, thanks for the prompt response. Since we should be going along the county line looking for unconnected ways anyway, simply deleting one of the duplicate ways doesn't add too much to the effort. Granack

Related bug/feature report

http://trac.openstreetmap.org/ticket/2708 --NE2 11:48, 11 February 2010 (UTC)


Tutorial needs updating

This tutorial looks very dated, with it's 2009 SOTM banner. Needs an update (or at least crop away that left hand side in each screenshot) -- Harry Wood (talk) 02:40, 6 January 2015 (UTC)