When I was a boy each train had a conductor who would walk through the carriages checking that the passengers all had tickets. If you didn't have a ticket then you could purchase one from the conductor. One day the Government decided that conductors were expensive and inefficient, I have memories of people protesting and complaining when it was announced that the conductors would be laid off. You had to buy your own ticket before you boarded the train and you could be fined if you were caught without one. This new strategy obviously did not work because now the trains have "transit guards" who walk through the carriages checking tickets. Except that if you don't have a ticket you can't purchase one from them, instead they fine you.
This is known as progress.