At the moment in Sweden, the railways tagged as usage=main are based on the EU TEN-T core and comprehensive networks. I think that it would be better to use something different for this tagging, as the EU designation sets the boundary quite high for being included, so many railways that are important nationally or regionally are not included and are thus tagged as usage=branch.
@leojth suggested to me that the Trafikverket track types (bantyper) could be used instead. There are 8 categories of railways. The NJDB map viewer shows the track types (select ‘statligt järnvägsnät’ then ‘bantyp’).
I suggest using track types 2 (Tracks forming major continuous corridors) and 3 (Lines comprising major freight routes with significant passenger traffic) as usage=main, along with track type 1 (Railways in metropolitan areas), where it connects to those.
This would mean that quite a few railway lines are upgraded to usage=main, but also that a few are downgraded to usage=branch. There is also the case of Inlandsbanan, which is not included in the classification system as it is not run by Trafikverket. I am unsure if it should be usage=main due to its length, but this can be discussed.
Currently in Sweden, a lot fewer railway lines are tagged as main lines than in most other countries. If you look at OpenRailwayMap, you can see that hardly any of Sweden’s railways are visible at larger zoom levels.This proposal would mean that Sweden is brought more in line with international tagging standards and that data consumers would have better data on which lines in Sweden are important.
Please give me your thoughts!