[OSM-talk] Maximum recommended length of ways tagged with layer

[Richard Z.]

On Fri, Mar 21, 2014 at 03:41:45PM -0500, Paul Johnson wrote:
> This seems like a solution looking for a problem than anything actually
> pragmatic and worth doing.  It would also needlessly overcomplicate cities
> that have large areas underground on multiple levels, such as Kansas City.

Example of a problem this should catch: I have seen cases where someone 
wanted to tag a simple bridge with layer and added the layer to the wrong 
segment - tagging a hundred or more miles of road accidentally, possibly
affecting crossings far away for an area not downloaded. The validator will 
not detect it and in most cases the renderer will work around this bug very
well so it is only discovered by accident in most cases. 
This is not limited to layer, I have seen the same problem with culverts and 
bridges.

What kind of underground areas are that in Kansas, do you have a pointer? 

Richard