Neither. The highway engineer got told to add a bike lane, said "ugh fine" and scribbled it along the side without thinking about it.
Nobody's expecting these to be used, it's some quota where they have to build X number of kms of bike lane so the politicians can placate us and hope nobody notices.
Depends on the train obviously, but a lot less than cars at anywhere close to capacity. Why do you ask? Just look at the Wikipedia page for whichever rolling stock you were thinking of.