[Tagging] Conditional restrictions accepted – turn restrictions ahead?
colin.smale at xs4all.nl
Tue Oct 16 17:30:57 GMT 2012
On 16/10/2012 17:45, Rob Nickerson wrote:
> Hi Eckhart,
> Your right, voting has come to an end for the Conditional Restrictions
> proposal, which was approved. A statement was not made on this list as
> Ole and I are working on how best to write the feature page so that
> some of the concerns raised (about complexity / difficulty to
> understand) are reduced as much as possible.
> Like Martin, I'm not hugely convinced about the need for complicated
> turn restrictions (most of the restrictions will be on the road and
> the detail on the turn sign will simply be advanced warning for the
> driver). Having said that, you have provided a few examples so I have
> looked into it:
> 1. Currently we tag a no left turn restriction using "restriction =
> 2. If we want this to apply only to HGVs then the key is changed so
> that it become "restriction:hgv =no_left_turn".
> To draw the comparison with "Conditional Restrictions" the above tags
> cover of <restriction type>, <transportation mode> and the tag value.
> There is no need to specify <direction> as this is already captured in
> the relation (from, via, to).
I am not sure you can say this. It should work where the junction angles
are close to 90 degrees, but for a shallow "Y" junction things might
need a hint as to whether it is a curve to the right with a junction to
the left, or a curve to the left with a junction to the right. The type
of restriction should reflect the road signs. At a T-junction, a
mandatory left turn could be considered different to a no right turn,
even if they are effectively the same thing. This cannot be derived from
the geometry alone.
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