[Talk-us] Changeset to revert (or defend?)

[Nathan Edgars II]

I'll repeat what I told him through the OSM messaging system:

> First of all, how did you determine that these features were in fact "ground-level"? Many times when I set layer=-1 on something it's at least a few feet below the surrounding terrain, if not more.

That's still ground-level. Look at the contour lines on a topo map;
they'll dip down to follow manmade cuts. Negative layers are for
tunnels that are underneath ground level (layer 0).
>
> Secondly, it is apparent that you didn't check the layer tags of all features (such as bridges) that pass over these "ground-level features". Now there are many instances of layer-0 bridges crossing over roads that do not have any layer tags.

Sounds like the problem is tagging the bridges as layer=0. A bridge
is, by definition, usually above the immediate ground level. If you
wish, I can go looking for bridges tagged as layer=0 and change them
to layer=1.

By the way, the immediate impetus for removing said negative layers
was the large number of highways tagged layer=-1 in areas far from any
bridges. So you'd have the main street through a town supposedly
underneath any intersecting features (rendered as such and logically
such in the underlying data). You may have noticed many
residential/unclassified highways rendering above these more major
layer=-1 roads. This is probably one of the initial reasons for giving
bridges positive layers; they're already split from the longer ways.