I like to rename trains. Anyone else does this? What should be the best system? Renaming to schedule (eg. Regional 4) or to class?
I name my trains after the line, which in turn is named after the stops being served (and goods type for freight trains). I name my ships with proper ship names because ships are usually named in real-life. I don't name road vehicles because there is too many of them. Buy them and setting up their routes are enough of a hassle as it is. I don't name my aircraft because I've never had a reason to do so.
I don't think there's a global rule that works for everybody. I generally don't name my vehicles, only my routes.
Too many vehicles for that. Especially in the early game with 120 trucks on one single long wood route... I do name my lines, however. always keeping the default number, adding extra information.