I am German and support the degradation of this "crime" to a delict, but even if 1/3 of the emprisoned is there bc of riding without a ticket, which I can hardly believe without a source, you leave out a very important aspect. Most if not all of those aren't emprisoned because they were caught 3 times without a ticket, but because they were on probation when they were caught. Most of those got probation immedeately in court. The law was created in the 1930s by the Nazi government because people "hacked" the new ticket machines, which weren't as secure as today. This wasn't an issue before when selling tickets was done by humans. Sadly western Germany always has been too conservative to change it, the reunification would have been a good chance to overthink every law that originated from the 3rd Reich.