Prefer local network versus E-road network in shield creation

[nvkelso]

• What did you see? E-roads are useful, but usually as auxiliary to the local A-road, M-road & etc tagging.
• What did you expect to see? See the local A-road first as default network and shield_text values. The e-road should only be included in the extra list of networks and shield_texts (which are included in GeoJSON and TopoJSON but not in MVT which is tangential but important as Tangram doesn't support multi-shields at this time).
• What map location are you having problems with? Europe. Rome, Milan, Amsterdam, etc.
• Screenshot?

http://localhost:8000/#11/41.8293/372.6037
In this case A90 is expected instead of E80.

[nvkelso]

For low zooms from Natural Earth we'll probably also need to prefer the local (A*, N*, etc) value instead of the label (E-road) value for default shields.

[zerebubuth]

It looks like this should be possible by tweaking the network importance by assigning a high value (higher means less important) to network_code when it's an "E-road". See also a previous comment, which makes me think we might need to do this on a region-by-region basis, depending on what the local visibility of these names is (i.e: US interstates are the equivalent of EU "e-roads" in network hierarchy, but interstates are much more prominently signed).

[nvkelso]

Good low hanging fruit 🥝 🍌 🍒 🍓 🍏