motorway_link and motorway_junction

dorkmo · 2018-12-17T04:03:32.000Z

A fellow map editor and I are discussing where the motorway_junction node should be place in relation to the end of the dashed lines of an off ramp.

We feel that the wiki images may be outdated based on changes in the way lanes are now tagged.

We have also found that different editors in different regions have varrying standards for placing the junction.

I’ve started a dicussion topic here:
https://wiki.openstreetmap.org/wiki/Talk:Tag:highway%3Dmotorway_junction#Picture_Example

It would also be nice to update Image 2 with a junction node for clarity
https://wiki.openstreetmap.org/wiki/Tag:highway=motorway_link#How_to_map

In light of the different views on this, what do you guys think the best to mark an off ramp are, and how can we better document that so that it can become standard in map editing.

Thanks,
Dorkmo

Tigerfell · 2018-12-17T22:03:01.000Z

Hi Dorkmo,

I could not really find a trend in the data compared to the aerial imagery.

The wiki is not consistent across its pages. https://wiki.openstreetmap.org/wiki/Tag:highway%3Dmotorway_junction states

This node should be positioned as the last point before the splay at which it is still possible to make a smooth turn.

Whilst image 2 suggests to extend the off-ramp backwards until it meets the highway. The German translation says that the node should be placed at the point where the roads divide (either by a sign post, a divider, or grassland in-between).

That is about the same what I found on OSM:

https://www.openstreetmap.org/edit?node=30230506#map=19/47.57704/-122.31952 (Seattle) This looks like image 2, but changing is probably not possible where the node is located as there is a straight line.
https://www.openstreetmap.org/edit#map=19/48.13892/11.39679 similar situation near Munich. Seems to align with the quoted wiki page instead of its German translation.

All in all, it looks to me as there is no generally applied solution (but that is difficult to see with so few examples).

We feel that the wiki images may be outdated based on changes in the way lanes are now tagged.

What are you referring to in this statement?

I would consider discussing this in a mailing list like tagging@openstreetmap.org.

Tigerfell