[OSM-talk] prohibited manoeuvres

[guy at graviles-reynolds.org]

Quoting Robert Scott <lists at riscott.ukfsn.org>:

> On Wednesday 07 February 2007 21:06, Scott Waye wrote:
> > I much prefer putting tags on the node:
> >
> > <node>
> >    <no_turn from="seg_id_x" to_seg="seg_id_y">
> 
> Such a scheme would have to be able to withstand the potential abolition of
> 
> segments ( which I haven't heard much about recently - has the plan been 
> shelved? ) and probably use 'next-node-id's instead.
>

I have also been considering this problem and come to a similar conclusion that 
the node needs to be tagged with the (non)allowed transitions. These could 
either be segment based or way based, though the ways would have to terminate 
at the junction node. I would go for a no_transition rather than a no_turn 
since the restriction could be go straight ahead, and since you are listing the 
(non)allowed transition from/to pairs, as far as I have been able to ascertain 
even the most complex of junctions can be catered for, you just end up with a 
long list of transition pairs.

However the problem is not just the potential abolition of segments, but the 
general editing of the dataset as a whole that is a problem, since the node 
could be left untouched and the ways and segments deleted and created many 
times over, leaving the transition data incorrect

Guy 'Batchoy' Reynolds