I'd also be curious for actual numbers, but certainly on the commuter GO Train in Ontario, it's basically a 3-4 person staffing arrangement, with one person at

I'd also be curious for actual numbers, but certainly on the commuter GO Train in Ontario, it's basically a 3-4 person staffing arrangement, with one person at the back, one in the middle in the accessible coach, and 1-2 in the locomotive. Adding someone whose job it is to roam up and down the train checking tickets adds 25% to the personnel cost, which is why most fares aren't checked. But quite apart from the person and their ticket-scanner, there's also the whole infrastructure associated with fare taking— fare-free advocates argue that if you get rid of the machines and websites and apps, and all the associated upkeep, it ends up being a wash. Of course this only counts if you're getting rid of all fares rather than doing a one-off summer special.