Isn't this how some public transport works (at least in the UK)? There's only a limited number of inspectors on the trams in Manchester so I probably won't get stopped but I don't know where they will be. I think the outcome is that the punishment has to be significant enough otherwise people work the probabilities.
(Note I always buy a ticket because I can afford it and want successful public transport.)
(Note I always buy a ticket because I can afford it and want successful public transport.)