[OSM-talk] prohibited manoeuvres

[A Morris]

Here is a simple but common example off the top of my head. apologies for
the poor ascii art... this is two dual carriageways meeting at a crossroads.
The prohibited manoeuvre is "no u turn" from A to B. This is 3 segments/2
nodes.

Maybe we turn right from A to C. There could be a prohibition turning left
into D but only for vehicles making the right turn) This is 4 segments/3
nodes.


           |   |
           ^   v      D
           |   |      |
           |   |      |
-->----------------->--- C
           |   |
--<-----------------<---
           |   |
           |   |
           ^   v
         A |   | B

On 2/7/07, Scott Waye <scott at waye.co.uk> wrote:
> Can't say without an example.
>
> A Morris wrote:
>
> > Prohibited manoeuvres can span many nodes though, could your scheme
> > cope with that?
> >
> >
> > On 2/7/07, *Scott Waye* <scott at waye.co.uk <mailto:scott at waye.co.uk>>
> > wrote:
> >
> >     I much prefer putting tags on the node:
> >
> >     <node>
> >        <no_turn from="seg_id_x" to_seg="seg_id_y">
> >
> >     I have implemented an A* algorithm for osm and I think this would
> >     be the
> >     easiest one to incorporate.  Anything with "left"s, "fourth left",
is
> >     just a pain.
> >
> >     Andy Allan wrote:
> >
> >     >On 2/5/07, A Morris <aledmorris2 at gmail.com
> >     <mailto:aledmorris2 at gmail.com>> wrote:
> >     >
> >     >
> >     >>How about this:
> >     >>
> >     >>
> >     >>
> >     >
> >     >See
> >
http://wiki.openstreetmap.org/index.php/Proposed_features/Routing:_turn_restrictions
> >     >for the non-concluded discussions. As for an example of a more
> >     >complicated restriction, here's one from where I live:
> >     >
> >     >No right turn between 8am-7pm (except buses and cycles) - I should
> >     >really pop over and grab a photo of it.
> >     >
> >     >If you're willing to take this challenge on, my advice would be to
> >     >gather as many real-life restrictions ( i.e. photographs) as
possible
> >     >BEFORE coming up with a solution, otherwise you'll end up bolting
on
> >     >quick fixes as you go along. And be careful, plans have been
> >     suggested
> >     >a number of times to remove segments from OSM at some point.
> >     >
> >     >_______________________________________________
> >     >talk mailing list
> >     >talk at openstreetmap.org <mailto:talk at openstreetmap.org>
> >     > http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
> >     >
> >     >
> >
> >
>
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