[talk-au] maxheight/height

[Stephen Hope]

No, you're wrong here. Maxheight is an element of the way that goes
under the bridge.  It is caused by the bridge, but it is not part of
the bridge.  It is the road under the bridge that has the limitation,
not the bridge. Divided roads often have different max heights on each
side, but it is one level bridge over the top.

Max-height can be caused by overhanging trees, low wires, odd road
signs that stick out over the road, even buildings or roadside rocks
that bulge out over the road. Whatever the cause, it is the road
itself that is affected, and should be tagged.  On a motorway, the max
height section can be several km long - the distance between exits,
and it is all covered by the same limitation, legally. On other roads
it may be only a few meters, and could be covered by a node tag.

Stephen


2009/7/28 Roy Wallace <waldo000000 at gmail.com>:
>
> For 1), what should be tagged? Definitely the bridge. For two reasons:
> firstly, clearance under a bridge is an attribute of the bridge.
> Secondly, it is not possible to refer to "the section of the way that
> is under the bridge", because the bridge is a way with zero width. The
> only alternative is to tag "the entire length of any way that goes
> under the bridge" or "some arbitrary length of any way that goes under
> the bridge". I think these alternatives are undesirable at best -
> misleading and messy at worst. For example, it's kind of like tagging
> any house that's next to a park as "next_to_a_park=yes", rather than
> tagging the big grassy area as "leisure=park" (yes, this is an
> exaggeration, but the analogy is tagging the thing that is affected by
> something rather than tagging the something itself).
>