I think the number of trips says a lot about the role trains play in people’s everyday lives, maybe even more than the kilometers travelled. Sure, that’s not a “metric”, but it does give us an idea if people use trains just for vacation a few times a year, or for their commute to work or other daily trips. For someone taking a train just once a year, even if that is for hundeds of kilometers, we know that they will use a different means of transportation for most trips.