OpenStreetMap
Where's my Bridge? Where's my trails?
Posted by z-dude on 2 August 2010 in English. Last updated on 6 August 2010.Edit: It seems to be a feature of editing software that does things when trails get split.
1. What happened to my trails?
I find that some of the trails that I added a year or so ago no longer have my name on them. At this time OSM is having a debate over the 'gpl like' license and requiring people who use OSM data to attribute the database, yet the trails that I added now seem to have someone else's name on them and the contributions I made are not attributed as per the creative commons license.
An example is the central valley greenway
I added http://www.openstreetmap.org/browse/way/36058157/history back in June last year, but when I click on the Central Valley Greenway now, I see it's got a new number, http://www.openstreetmap.org/browse/way/41769632 and someone else is credited. I see the same thing at Mundy park, Delta Watershed, Burnaby mountain.
2. Where's my bridge?
Deleted, that's where. http://www.openstreetmap.org/browse/way/58568202/history
I went and re added it. It sucks that it went missing though.
It's a downer to see my local trail not have my contribution on it any more, and to have seen that bridge get deleted.
My advice to those of you using JOSM or other programs.. don't delete other people's contributions. Merge the data without destroying the attribution info.
Basically, don't take an eraser to someone else's trails and slap your name on it unless you're removing a completely inaccurate track (>30 meters accuracy) with a more accurate track (an average of several GPX traces for example)
OSM really needs work, and to fix it, you really need people to help, and that means accepting their edits, because the current status of the map in Vancouver is full of streets that aren't properly connected to other streets.
ie.. the people on Bear Creek Drive can't get out of their street! http://www.openstreetmap.org/?lat=49.1500425338745&lon=-122.831869125366&zoom=16
So be good to the guys who fix things like that. You really don't want to delete other people's fixes just because you imported some faulty data from Canvec.
You really want to have some new guy tell his friends 'Hey, I added THIS trail to your GPS' because that way, you'll get a lot of people making our local map better.
Discussion
Comment from JohnSmith on 2 August 2010 at 05:49
This is actually going to be a big problem for OSM in future, currently when you split ways, depending on the editor being used, one way may keep the old ID number and in turn the history for the way ID, but some editors have not only created a new way which doesn't inherient the history of the old way, but may have created 2 new ways although this was most likely a bug.
Then if ways are merged again it's pot luck if the main history is kept or not.
Comment from JohnSmith on 2 August 2010 at 05:52
If you want attribution that sticks, I suggest you tag your ways with attribution=Copyright 2010, kindly donated by
This should, survive merges and splits, and there is a lot of other cc-by attributions already in the DB so it shouldn't be removed.
Comment from emj on 2 August 2010 at 07:12
the nodes are still yours.
Comment from Richard on 2 August 2010 at 08:01
When someone splits a way (let's say, they split ABCDE into ABC and CDE) for whatever reason, the original way is truncated to ABC, and a new way formed comprising CDE. The new way is just that - new - so doesn't have any history. Therefore the attribution is lost.
It looks like this is what's happened in case 1. OSM is not really a project for putting your own name in lights, it's a communal project.
For case 2, I'd suggest you drop the mapper who deleted the bridge a friendly note saying "hey, could I ask what you were doing?". It might have been an accident or there might be a good reason. You can contact him/her by clicking on their name then on "send message".
Comment from Richard on 2 August 2010 at 08:02
Ugh, and the fricking caching meant that my reply echoed what several people had said earlier. :| Ah well.
Comment from Kevin Steinhardt on 3 August 2010 at 19:01
Attribution?; isn't it a situation of 'no-one owns the data; everyone owns the data'?
Comment from mbiker_imports_and_more on 6 August 2010 at 00:55
Hmm. I'd like to think I'm careful with other people's edits. And I'm pretty sure that when I added 41769632, there was no trail on the map there (to the west of North Road, that is). Should be easy enough to get an old planet dump and check.
Comment from mbiker_imports_and_more on 6 August 2010 at 00:57
I take that back.. there was a track before. Not sure what happened there. Sorry!