Add train traffic
as for plane traffic, add train traffic.
exemple carto.graou.info with data from https://data.sncf.com/pages/accueil/
I don't know if there is opendata for other countries
It might me impossible to accurately place trains on tracks. It's a very common sight to see a lot of parallel tracks that are located very close to each other, especially on train stations. GPS data (or whatever they use to track trains) might be not accurate enough, and the same goes for OSM ways that might not be mapped very accurately.
BTW, there's also an API for the NL: https://en.treinposities.nl/
FYI there are various APIs in various countries / transport companies but note:
- live traffic has nothing to do with OpenStreetMap
- the APIs may not (all) be free to use
- there are countless APIs, to me it sounds like a project on its own to bundle them all together into one for easy (international) consumption. To my knowledge, there is none that is open source.