boundary relation should not circle whole areas


I’ve created my first relation in OSM today:

It is the boundary of the “Katastralgemeinde Obermallebarn”. I have got a problem here:

The forest on the left side and the green area (Golfclub) make up the boundary, but the boundary does not circle these areas. How can I correct my mistake? Do I have to take the polygon of the forest and the Golfclub and split its polygon lines, such that only the boundary parts are assigned the relation? Is there another relation type to achieve what I need?

See this image for a visual representation of my problem:

Hello Robert, welcome to the OSM forum!

First of all, you can also ask in the German subforum here, it has more traffic and more users.

According to your edit history at I see that you are using the Potlatch2 editor.

If you want to work with relations in a more intensive way, I really recommend to use the JOSM editor … it has a really awesome relation editor.

The objects in focus are and
It is the best choice to **split **these two closed ways at the points where the other boundaries come and go from the left and right side. Because you can only include the parts of that ways that show a closed line track like the boundary is in real world.

Also pay attention to this boundary line:

If your boundary is identical with the bigger boundary, then there should be NO DOUBLE line.

Tell us whether you come alomg with these instructions or someone should work on one example and you doo the rest. Because learning by doing is very important at OSM.

Thank you very much. Yeah - I’m using Potlach2 although I do not like Flash, but it is convenient, because it is available on nearly any computer.

Thanks for your advice on using JOSM - I really have to look at its possibilities.

Splitting ways was the possibility I thought of, but I hoped that there might be some relation type that marks the area as excluded.

I’m aware of the additional boundary line (which should be identical). I have used a very old map to find out about the boundary of our “Katastralgemeinde” (“Katastralgemeinde” [] < community < district []). I need to visit our municipal office (“Gemeindeamt”) for more information. I will address this issue soon.

The OSM community and its projects are great! Thank your very much for your help.

Now, I got real problems:

The forest is gone.

The golfclub is gone.

What could be done to fix this problem. I split the polygons forming the forest, respectively the golfclub. What should I do now?

Possibility 1: Can forests and areas be shown as relation too?

Possibility 2: Draw a way above another. I know, this is bad practice…

Possibility X: ?

Hello There,

The forest and golf club boundary’s are reinstated, I think you had split them and used the split off section for your new relation. This left the forest and golf club only half drawn, I extended re-drew the old section over the existing nodes to complete the circumferences.

I think you still have a problem that the ways used in your new relation are utilising complete ways. The ways must be split so that you only use the sections relevant to your relation in it. The new relation is still not correct.


Please check the new relation, could be OK now. I did get two warnings but could not see a problem.

Someone suggested JOSM as a preferred editor, (my preference also), in JOSM you also have the ability to work on an area, saving it offline and only uploading it when it’s complete.


In my opinion the right solution is to draw the golf club and the forest as areas (not splitted), like they were in the beginning. The administrative boundary should be drawn as independent line tagged boundary=administrative and added to the boundary relation. There will be double lines at the edge of the forest and the golf club, but it doesn’t matter, because the type and function of them is quite different.

robert|koch → I see there is another higher level boundary. I think you should rather split that existing boundary line and add a part of it to the new relation. Of course if your data are more accurate than existing you should correct this boundary. Remember that the shared section of the boundary should be in two relations: this of higher level and your town boundary.

Thanks @BCNorwich, @JakubS.
You’re right - your proposed solution sounds nice - I will draw the boundary line on top of the overlapping polygon edges.

@higher level boundary: You’re right - there is a higher level boundary - I was at the muncipal office today in order to retrieve an updated map. I will soon join them together.