[talk-au] maxheight/height

Roy Wallace waldo000000 at gmail.com
Tue Jul 28 01:31:51 BST 2009

On Tue, Jul 28, 2009 at 10:10 AM, Stephen Hope<slhope at gmail.com> wrote:
> 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.

You're saying that the clearance under a bridge is not an attribute of
the bridge? I'm not at all convinced of that. But it is subjective, so
we may have to agree to disagree.

> 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.

Good point, though I would suspect this is relatively rare (i.e. I've
never seen this).

> 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.

I disagree. We should be tagging "things", not tagging the "effect of things".

> 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.

Sounds like a maintenance nightmare. I'm also not sure that a
"clearance" under a bridge is equivalent to a "legal limitation" for
the section of motorway between the exits before and after the bridge,
as you say. And what if a motorway and bridge are tagged, but exits
are missing, etc. Just sounds a lot harder to maintain than tagging
the bridge itself.

Can you explain what you mean by "may be only a few meters", and
"could be covered by a node tag"? If you can specify an exact
preferred way of tagging this (and document it on the wiki), I may
well be convinced.


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