>>1740687>depending on the system the destination might not be recordedWell, no. If a destination isn't required - example from the top of my head, London buses, which operate on a single flat fare payable on boarding - then this data of course won't be recorded. In which case, it will almost certainly be recorded that X route was used by Y people at Z times of day etc intead.
>the purchasing time might not be the same as the travel timeThey're probably recording both. One to offer advance-booking discounts (or walk-up 'distress purchase' price-gouging...), and another to book a specific timetabled train service.
>nothing is recorded if you buy week/month/year ticketsDitto my first point, because of course tickets will be validated somehow (otherwise, why have the ticket to begin with).
I'm not saying that anonymous travel doesn't exist, because of course anybody can buy a train ticket from a machine and pay in cash. However, that data will be stored and used to ensure that the ticket you bought is valid - and for statistical purposes as well.