Relations/Proposed/Junctions
From OpenStreetMap
This is a proposal for a set of tags and members making a Relation to group the ways and/or nodes comprising a road junction.
The main purpose of the Relation at present is to give renderers or route planners a name and or number for a junction. It also means that a staggered cross roads controlled by linked traffic signals can be grouped into the one junction while still maintaining the geometry of the streets correctly.
I can see it possibly developing in time to be a place where other aspects of the junction can be modeled.
Tags
| Key | Value | Discussion |
|---|---|---|
| type | junction | |
| junction | roundabout / link | link is for clover leaf and similar type junctions; just omit this tag for junctions like cross-roads and simple single-bridge motorway junctions (unless someone can suggest a vocabulary for them) |
| grade_separated | yes | if it is grade separated (perhaps this can be used to imply layering and bridges without having to individually model each?) |
| name | a name | if the junction has a name (e.g. "Charlie Brown's Roundabout") |
| ref | a reference | if the junction has a number (e.g. junction 10 on a motorways would be "10") |
Members
| Way or Node | Role | Recurrence? | Discussion |
|---|---|---|---|
  | (blank) | one or more | the ways and/or nodes comprising the junction (a typical grade separated motorway junction would combine ways, but a simple cross roads only has a node comprising it. A single carriageway crossing a dual carriageway might include the two nodes and the link between the carriageways in the junction. |
| | location_hint | optionally one | a hint to a renderer as to where a good place to put the the junction number or name on the map |
