|It has been proposed that this page or section be merged with Proposed_features/Junction. (Discuss)|
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.
Need for a relation
For a simple crossing where 2 ways cross each other at a single node it is not necessary the use a relation. It is obvious that the only the node where the 2 ways cross is part of the junction. The need for a relation occurs when there are ways and or nodes which could be considered part of 2 or more ways. An example would be a dual carriage way crossing a single carriage way. The piece of way between the dual carriage way and also the intersecting nodes could be considered part of both ways.
|junction||SeeProposed features/Junction||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)|
|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")|