[OSM-talk] Clarifying and representing road markings at junctions

[Frederik Ramm]

Hi,

Roy Wallace wrote:
> In that case, use a relation. Two options:

> 1) http://wiki.openstreetmap.org/wiki/Relations/Proposed/Segmented_Tag

[...]
> 2) http://wiki.openstreetmap.org/wiki/Relations/Proposed/Collected_Ways

Both don't go far enough in my opinion. This is not a question of "how 
can I express that two ways actually belong together", but the more 
general question of "how can I model hints about the way in which the 
physical junction presents itself to the driver".

For example you might have a junction that, in the OSM node/way 
representation, looks like a sideways "T" (i.e. it looks as if you can 
go straight on if you come from the South), and in reality it is Y 
shaped where if you come from the South you can either go half-left or 
half-right but never straight on. This, too, is a situation where you 
would want to model extra routing hints, and many others are possible.

Bye
Frederik