[Tagging] Tunnels and bridges

[Peter Wendorff]

Am 31.01.2013 18:14, schrieb Malcolm Herring:
> On 31/01/2013 15:17, Martin Vonwald wrote:
>> As you already need to
>> split the roads at the edges of the structure, because you need to add
>> the layer (and bridge) key within the structure, there are already
>> nodes present - just connect them with the OSM way of the structure.
>
> Why do you need split the road at the edges of the bridges? This is 
> currently done because it is the only way of defining the bridge. If 
> we are to split the two features, then this need disappears. If the 
> bridge crossing ways have width or weight limits, these do not 
> necessarily coincide with the structural limits of the bridges. They 
> often apply to the approaches as well, so the section of the road 
> where the restriction applies begins and ends beyond the bridge.
+0.5
I agree that this is nice in future, but for compatibility reasons I 
would propose a slow progress towards what you describe: if the bridge 
is already there the ways are splitted, the bridge highway is already 
there and so on - so: keep them splitted and it's less work with more 
backwards compatibility.
If they are not, it's up to you as a mapper if you want outdated 
renderers to use the old scheme or not.

regards
Peter