When evaluating whether to map an underpass as a tunnel or the feature that runs atop as a bridge, where would you draw the line?
I was looking at this railroad underpass and to me it seems like a bridge since the railroad looks like it is being carried on a structure.
How would you map this situation and where is a tunnel really a bridge?
That looks a lot like a bridge!
To the actual question: Why should I reinvent the wheel? This answer from someone else in another discussion could possibly clear things up:
You have linked only to map data. What does it look like in person?
Is there soil/earth/rock/etc between feature running on top and feature running below.
KartaView looks like a bridge to me but maybe in-person survey reveals some extra info.
Another vote for bridge. Looks like a fairly typical railway embankment cut through with a bridge/underpass. It also looks like there is a railway siding starting just east of the bridge and going west that is not mapped.
First the walls of the underpass are build, quasi the bridge piers, the ceiling/roof put on top, the rail/road embankment completed filled up against the passage walls, and the rail/road laid on top and over. Bridge, and the funny is the double rail along the coast has many of these underpasses that are lower than the maxheight default of 4.80m and therefor have 2 signs both ends telling what the maxheight is and a second sign “ponte basso”, low bridge, the lowest nearby just 1.8m, bus drivers warned not to try as a 3rd sign. But there are some mappers coming to visit on occasion in their armchair and change a few to tunnel, yet leave the mapped bridge areas alone, at layer=1 and so one has an under passage with layer 1 on top and layer -1 below.
Bridges they are, the OP one too. At any case, nothing natural between underpass ceiling and road/rail.
Now we see, 13 feet 6 inches maxheight for the underpass section 