I went to a high school that revolved around an “honor code” for cheating. You were expected to avoid cheating and turn in classmates (and friends) who did to a jury of your peers. I was on said jury, too.
I’ve always bought fares even when I was sure I wouldn’t be checked, even when it was commuter rail and multiple dollars each way. In New York, at a time when they’re really strapped for cash, I think you have to question the honor system.