Using relation tags to nodes in OpenStreetMap?

Question

I filter an osm planet extract using osmfilter. I am only interested in nodes belonging to route=subway relations. After performing this operation, I use osm2psql to load all the data into my postgres db.

The thing is that I don't know to which relation name belongs each node. I mean, I know all nodes belong to route=subway relations, but I don't know the name of the relations.

So, if I have a relation with these tags: route=subway, name='Line 23', I would like that all the nodes belonging to this relation had also the relation tags. For example: name:'5th street station', relation_route=subway, relation_name='Line 23'.

How can I do this?

Answer 1

I wrote a small nodejs program that performs the task: tags2nodes.

You have to specify the osm input file, the relation you want to filter, the postgres user and db data and the program creates a table to store the ouput nodes with 3 columns: id, tags, and geometry. In the column tags (json stringified by default) you can find, besides the node tags, something like this:

relations : {relationid1:{name:'relation1 name', id:'relation1 id',...}, 
             relationid2:{name:'relation2 name', id:'relation2 id',...}}

Arguments detailed:

 -f      input osm.pbf file
 -u      postgres user
 -p      postgres password
 -h      postgres host
 -d      postgres db name
 -c      osm relation condition json. I.e.: {'route':'subway'}'
 -r      role of members of relation to be filtered. I.e.: stop
 -t      [optional] postgres output table name. Default: tags2nodes
 -j      [optional] output projection. Default: WGS84 (4326)
 --json  [optional] json tags field postgres format. Only valid for Postgres >= 9.3. Default: text
 --jsonb [optional] jsonb tags field postgres format (faster!). Only valid for Postgres >= 9.4. Default: text