I have family in the police and there are colossal amounts of fines that are unpaid and for far more serious offences than non payment of train fares.
I am in no way condoning what the OP did here but we have to be realistic.
True, in a previous life I used to take part in sweeps for people who had failed to attend court or had failed to pay fines. Basically a "Wanted on Warrant" search. We would get a big list in the morning, a large van and go hunting - a good result was 5 - 10%. However when we caught someone it was straight to jail, no bail until they could see the sheriff on the next legal day.
It was quite hard tracking down the usual transient underclass but we did pick up a few folk who should have known better but were just putting their heads in the sand.
To be fair I think we only did this about once a quarter in our division and things have no doubt changed in the last 20 years.