Proposal:Area highway/mapping guidelines
This page shows how to divide streets and their junctions in separate area:highway elements.
An exampe of possible x-junction:
Dividing of simple crossings without pedestrian ways marked on the street surface
Turning circles and dead ends
Simple turning circle. The turning area is drawn as separate area:highway=turning_circle area.
Rendering of lanes
Please note: the idea of lane rendering is recently nowhere realized.
Example of behaviour of rendering of areas with junction=y_junction tag:
Result after rendering:
The street of higher category, which has two common k points with the area:higway is used to render continuously the number of lanes. The street with lower or the same category but with only one common point k with the area:higway=* wil be ignored in rendering process:
Result after Rendering:
More complex crossings
Motorway and crossings with more levels
In case of more overlapped levels every area:highway should be drawn and get additionally tag layer=*.
Note: In this case: all polygons have area:highway=* (probably motorway, motorway_link or trunk), this one with orange J's have additionally junction=* tag, blue colored polygons gets additionally tag: layer=1.
Border of service roads
It is not necessary to draw an junction area in case of: service roads, footways, cycleways trucks and generic roads.
Due to the recent approach not physical street dividers are ignored.
This mapping makes advanced lane rendering impossible.
For right rendering we should divide this street in three areas:
We need also two separate oneways (note that it NOT an accepted tagging to split road into two oneways in such case):
The result could be rendered similar to this mockup:
If the lanes and turn:lanes attributation exist, the lanes and turn restrictions can be visualized.
Simple crossing example
Crossing from here.
Rendering interpretation of the tag direction