OpenStreetMap
Not only “the mole people” live underground, as there are large urban areas, publicly accessible, built below the ground level, and indoors in general.
As an example of an indoor world: Easton Helsinki, in Finland, which has about 4.8 million visitors per annum. (Source.) It’s built on multiple levels. OpenStreetMap doesn’t yet have support for such multi-levelled maps, but it could: a level is just a layer.
Mostly underground is the bus terminal at Kamppi, in Helsinki. It has elevators and escalators carrying countless people up and down, in and out of tunnels and halls. Most of this world underground isn’t yet seen in OpenStreetMap.
Discussion
Comment from WilleGIS on 26 October 2022 at 15:13
This would be an awesome edition to openstreetmap.
However there might be many reasons why this is unlikely to be added. 1. Imagery 2. Downloadability.
There are tools that make mapping easier in malls and on the go mapping. Maybe this type of tool would be effective in aiding efforts to map underground, although these apps require GPS functionality.
Definitely if this is something you want to start working on and pushing for. GO FOR IT.
Comment from Kovoschiz on 26 October 2022 at 15:39
Both “OpenStreetMap doesn’t yet have support for such multi-levelled maps” and “ Most of this world underground isn’t yet seen in OpenStreetMap.” are not entirely true. There is already Indoor= and OpenLevelUp, alongside JOSM’s built-in
level=filtering. The question is where do you draw the line betweentunnel=/https://wiki.openstreetmap.org/wiki/Tag:man_made=tunnelandindoor=/building=, as well as how to model the levels. The use ofhttps://wiki.openstreetmap.org/wiki/Tag:building=train_station+https://wiki.openstreetmap.org/wiki/Tag:location=ground+building:levels:underground=for underground rail stations in general has been discussed before. Kamppi already has the basics added around node/1378007259#map=19/60.16902/24.93236 withtunnel=. Rendering ofhttps://wiki.openstreetmap.org/wiki/Tag:highway=pedestrian+https://wiki.openstreetmap.org/wiki/Tag:area=yesabove everything else has been discussed in Carto fortunnel=https://github.com/gravitystorm/openstreetmap-carto/issues/529 andbuilding=https://github.com/gravitystorm/openstreetmap-carto/issues/688 with https://github.com/gravitystorm/openstreetmap-carto/pull/3872 closed.Comment from Kovoschiz on 26 October 2022 at 15:49
Showcasing them requires more than the layers currently shown. You need overlays, buttons, and detection. Clickable shapes for per-building view, since
level=currently shown for all buildings may not match. Essentially changed entirely.Comment from kuopassa on 27 October 2022 at 13:46
Thank you both, WilliamEdwardsGIS and Kovoschiz, for commenting. :-)
“Showcasing them requires more than the layers currently shown. You need overlays, buttons, and detection. Clickable shapes for per-building view, since level= currently shown for all buildings may not match. Essentially changed entirely.”
– This I think could be done with a layered approach and zoom in/out feature. When a user has enabled a special layer for peeking inside buildings/underground areas, the zoom feature could be used to basically just scroll deeper and shallower. I think most buildings, tunnels etc. are built in a standard way: the base unit is the height of an adult human, plus some extra. A room is typically something like 2-3 meters in height. That is the base unit, so for example a hall at a shopping mall can be 3 x base unit. The zoom feature could simply move deeper/shallower one base unit per zoom event. Clickable areas, detection etc. are redundant imo.