From OpenStreetMap Wiki
|highway = traffic_mirror|
|Used on these elements|
|Tools for this tag|
A traffic mirror is a mirror that reflects the traffic on one road to the point where vehicles from another direction are waiting to turn onto this street and the direct view is blocked.
- relation type=traffic_mirror
- a node where you are waiting, looking at the mirror: Relation role=from
- This is used if you have to give way to the other direction you can watch in the mirror.
- a node where you cross over after you have left the crossing: role=to
- This is used if from this point you do not have to give way to the street watched in the mirror (you don't really need it)
- highway=traffic_mirror for the pole with the node, relation role "mirror"
This should be a bi-directional node.