NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum

I am working in Potlatch 2 with a relation ( It is approaching 2000 points and I need to add more. I would like to split in two but I am unfamiliar how to do so. Is there a tutorial on how to do this?

asked 14 Jun '16, 00:20

flockfinder's gravatar image

accept rate: 0%

edited 14 Jun '16, 13:46

SimonPoole's gravatar image

SimonPoole ♦


just to clarify: not your relation is approaching 2000 nodes, but one of the member ways of the relation is approaching 2000 points. As far as I know, a relation would not have a technical member count limit.

(14 Jun '16, 06:31) aseerel4c26 ♦

In JOSM, this done by selecting 2 nodes and select 'Tools>Split Way'. I am not familiar with Potlatch.
But the Potlatch2 Guide states: "To split a way, select the point at which you want to cut, and click the Scissor tool (or press X on your keyboard)".
You will need to select 2 points to split the outer polygon into two parts.

I guess in your case, choose nodes so that each new way will be about equal in length, giving you ample room to expand each way as necessary. If I were doing it, I would probably select several nodes around the long outer polygon and split off each big lobe, but that is just a personal preference.

permanent link

answered 14 Jun '16, 04:38

nevw's gravatar image

accept rate: 9%

edited 14 Jun '16, 07:49


@flockfinder: this will split the ways, and afterwards both ways should be a member of the relation (Potlatch2 should do this for you).

(14 Jun '16, 06:34) aseerel4c26 ♦

Ok i use the x shortcut all the time. But I have never used it in a relation. So Potlatch 2 is smart enough to know when I insert a new way to in corporate it into the relation? Or must I add it manually. I'd hate to break a relation and not know how to fix it.

(14 Jun '16, 07:14) flockfinder

(as aseerel4c26 has already said) you're not splitting the relation, you're splitting a member way. When you split both parts will be part of the relation with the same "outer" role and both will have the same tags.

(14 Jun '16, 09:47) SomeoneElse ♦

@flockfinder: yes, any not-that-broken editor should automatically make the new split-off way (by X) a member too (or at least show you a warning and advice that you may want to do that manually). Of course this does not apply to expert editors / expert modes, but for a general OSM editor it would be quite destructive if it would not take care of relations when you split ways which are a relation member.

I cannot try it (since I do not use Flash), but I do not know different information about Potlatch2.

And in any case: I would encourage you to view the relation memberships of your new split-off way and confirm that the automation worked. It is good for the understanding of the data model.

(14 Jun '16, 19:50) aseerel4c26 ♦

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here



Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text]( "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:


question asked: 14 Jun '16, 00:20

question was seen: 2,567 times

last updated: 14 Jun '16, 19:50

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum