Dual Carriageway or not?

Communities United Kingdom
1

I am trying to resolve the note in the middle here - OpenStreetMap . Going north there is a clear barrier to start with then it goes into a wide cross hatched area and then a split at the next junction. It looks perfectly sensible as it is mapped at the moment but I can see that technically it doesn’t meet the dual carriageway criteria where the note is. However the Wiki says “A dual carriageway does not have to maintain a median or barrier throughout its entire extent to be mapped as a dual carriageway.”. Should I leave it as it is and close the note or change the road at this point?

2

You can simply comment on the note with that and refer to this discussion. I’m fine with your solution.

3

Non edit link.

1 Like
4

I would merge the roads as suggested by the note. Paint does not count as physical separation in this case. If it was only a short section without a central barrier, it would not be necessary to merge them.

The wiki also states "Roads are not to be mapped as dual carriageways if the two directions are only separated

  • by paint. This includes single or multiple painted centre lines[1], hatched areas, channelized turn lanes[2], two-way turn lanes[2],"

(Dual carriageway - OpenStreetMap Wiki)

1 Like
5

OK I’ve merged them - hopefully correctly.

6

It wasn’t quite correct, you dragged both roads to be sharing the same geometry (overlapping). The correct approach for dealing with merges is to delete one of the carriageways, then change the tags on the other to no longer be oneway and update the lane counts (which you did). You also have to update the bus routes to ensure they are still connected (admittedly not an easy job in iD). I have updated the routes and tidied the nearby junction up a bit so it should all be good now.

7

Thanks! I tried to do that but didn’t realise that one road was still hidden under the other one.