Hi. 
With this changeset you started to add micromapping to the Viadotto Monteroni. I have several comments for discussion / suggestions for corrections.
1) The man_made=bridge polygon should not coincide with the outer highway=footway linear  way, rather it should include them. The highway ways should only be connected to the short ends of the man_made=bridge polygon. See the schematics of the man_made=bridge wiki page.
2) The emergency highway=footway have no access points and no emergency stairways on the entire length of the viaduct. In order to reach them the pedestrian has to climb over a guardrail. Also they are very narrow. I would not map them at all. Alternatively one could map the guardrails, including height.
3) If the footways are mapped they should have correct width=* tags
4) You are using area:highway=trunk. That single polygon includes both highway=trunk carriageways. I would interpret the corresponding wiki page as requesting separate area:highway=trunk polygons for each direction.
5) Embankment tags are missing for the ramps that lead to the viaduct.
6) At the southern end the bridge=yes tag extends into the ramp part beyond the end of the emergency footways.
7) At the northern end of the viaduct the bridge=yes tags are present for a further 900m where the road is not on a bridge. Part of that is on an embankment that ends roughly behond the cemetery
8) South of Via Lauretana there is a dirt track that runs all the way under the western carriageway of the viaduct to its southern end. This is not mapped.

Volker (Padova)
