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

[Blaž Lorger]

On Wednesday 30 September 2009 21:00:12 Martin Koppenhoefer wrote:
> 2009/9/30 Blaž Lorger <blaz.lorger at triera.net>:
> > I don't see where problem lies.
> >
> > Is it that routing software will not be able to choose right route?
> > You never stated it clearly, but if I understand correctly road from
> > segment a to b has right of way over segment c. So all you need is a way
> > to indicate this. There are some proposals that could solve this (stop
> > signs, yield, right of way).
> > If there are turn restrictions you can map those using turn restriction
> > relation.
> > But if there is no explicit right of way and no turn restrictions it
> > really should not matter how road markings are painted on the road.
> > Routing software should be able to pick the right route based on other
> > criteria (road classification, speed limits, traffic calming, ...).
> 
> obviously you will find those road markings in situations, where there
> are some kind of restrictions or explicit right of way. The thing is
> less to _find_ the best way, but to give apropriate indications
> (follow the street to the right or something similar, at least not
> simply: turn right.
> 
> see this for explanations:
> 
> http://www.atzl.eu/stickerei/images/stories/stickerei/f03.jpg
> http://www.phipsl.de/fall1.jpg
> 
> http://cdn.fotocommunity.com/photos/10510230.jpg&imgrefurl=http://www.fotoc
> ommunity.de/pc/pc/display/10510230&usg=__A3IpXoI79f0MoS-wOtdSQLUJz3E=&h=100
> 0&w=659&sz=225&hl=de&start=12&um=1&tbnid=gU2vwxzupwOUYM:&tbnh=149&tbnw=98&p
> rev=/images%3Fq%3Dabknickende%2Bvorfahrt%26hl%3Dde%26client%3Dfirefox-a%26r
> ls%3Dcom.ubuntu:de:unofficial%26sa%3DN%26um%3D1

I was not able to open last one, but first two are cases where road with right 
of way is not the one going straight. By properly marking which way has right 
of way and making sure that junction geometry is correct, good navigation 
software should be able to produce sensible turn instructions without need for 
additional data.

 Blaz