Using authoritative data as GPS trace?

Is it acceptable to take some authoritative data, like a municipal street network file published as “open data”, convert it into something that looks like a GPS trace and upload it so that you and other users can use that for alignment of new and existing data?

How would your record the attribution and database rights licensing?

My feeling is that you couldn’t do that adequately with the GPS trace uploading mechanism.

The other problem is that, if the data has been accurately surveyed, one doesn’t want people tracing over it, one wants them to use the actual surveyed values.

People have done this in some places with admin boundary data, and personally I find it extremely confusing.

Admin boundary does sound like it’d be funky as gpx. Roads make a little more sense only because you’re traveling on them. I’ve tried using the Strava gps layers to line up imagery in JOSM, but most users don’t have that easy option and it isn’t everywhere I want it.

Attribution wise, you’d only be using the open data to line up bing which you would then use to align data that already exists.

The issue that I’ve got is that nearly all the roads in the city have been added, but inconsistent offsets have been used for different entity types in different areas of the city. I think it has to do with a projection issue of some data that was loaded and has now caused confusion. Example, you line up bing to the buildings the roads are off, line up bing to the roads the buildings are off. Different users have used each method.

My thought is that if you turned the authoritative data into GPS tracks then the existing roads could be moved, a consistent entity type established for offsetting imagery, and all data could be lined up nicely. GPS traces would then exist and should be part of the standard workflow for all existing users without any interaction. Using the open data source would mean replacing and copying attribution from 50000+ lines, and would need coordination between many users.


I use GPX all the time to get UK admin boundaries into OSM by using Potlatch2 to convert the trace to a way.

What’s confusing?

Both P2 (natively) and JOSM (via a plugin) can load shapefiles - there shouldn’t be any need to go via GPX.

Sure, but I find it more convenient to handle individual boundaries as individual files instead of loading a 200MB shapefile with over 10000 boundaries of which I am only interested in one (at a time). I never said there was a need to use GPX…

I can certainly load them into JOSM and get my own map aligned to work with. I’d like to get everyone working in my area setup with something to make it easy for them to do the same and get their data and imagery aligned consistently.

I imagine you load the gpx temporarily into Potlach and you do not upload the boundary gpx as a trace to OSM database. The latter would indeed be disturbing as others would certainly mistake the trace for something someone traveled on.


This is something that I can do very efficiently in Potlatch2 (in terms of mouse clicks). Although you can display a GPX trace in iD, you can’t convert it to a way (unless that has been added very recently).

It is the Openstreetmap GPS Traces layer that I’m more interested in rather than gpx specifically. GPX is simply the format I’m aware of to get data into that layer.