Proposed features/junction details
|Additional junction details|
|Status:||Proposals with undefined or invalid status (inactive)|
|Definition:||Specify the ref of the junction a way belongs to|
This proposal introduces the key junction:ref which allows to specify the reference of the junction a way belongs to.
Note: As of Nov 24th 2012 this key is already used about 6000 times according to taginfo.
Nowadays the big suppliers of navigational devices offers a roadsign view. The key destination=* and Proposed features/Destination details offer support for a roadsign view. The key junction:ref is necessary to support the roadsign view of both exit numbers as can be seen on these signs.
|junction:ref=2||Exit 2. This key should be used on the left way directly behind the motorway_junction node.|
|junction:ref=3||Exit 3. This key should be used on the right way directly behind the motorway_junction node.|
Why not stick to the ref=* in motorway_junction=*?
Good question. For normal motorway_exits the ref in the motorway_junction would be sufficient. However, there are some other reasons which make it more logical to use junction:ref.
1. Consistency in tagging. All other information to support a Roadsign view is stored in OSM ways, like maxspeed=*, lanes=*, destination=*, destination:ref=*. So why shouldn't the junction:ref info be stored in the way?
2. The current tagging of the motorway_junction node does not support the situation as shown above
Why not deprecate motorway_junction?
It's used too many times already. And it looks good in a renderer like Mapnik.
Why name it junction:ref?
Why not use ref=*?
The ref of the motorway_link is quite often the same as the ref of the motorway, like "A 3".
Please use the Discussion page for this.