I was waiting to go through a subway turnstile this morning and stood behind a guy who kept getting the dreaded "Swipe Card Again at This Turnstile" every time he tried using his MetroCard. There was only one turnstile at this subway entrance and the line behind this guy kept getting longer. The question I have is, how many times is too many times?

Late For Work, Upper West Side

From the pole-hugger to the guy who sits on a seat with his legs splayed out to the person who doesn't know the proper techniques for folding a newspaper while sandwiched between a dozen commuters, most people who breach subway etiquette are not so much rude as they are simply clueless. Since you seem more annoyed at the fact that this rider was utterly unaware of the growing line behind him, Ask Gothamist would be hesitant to put a limit on the number of times one can swipe and re-swipe a MetroCard in the event of an error message.

At a deserted station riders are free to swipe to their hearts' content. But once the line starts growing and those annoying messages simply won't go away, it's up to the individual to decide if it's worth ticking off the five, ten, twenty or more riders queuing up behind him.

The answer to your question is less a matter of establishing a rule as it is reinforcing the idea that those who use public transportation and share its confined quarters, narrow platforms and, yes, single turnstiles, should simply pay attention.

Gothamist on bent MetroCards and a term for people who don't know how to swipe properly.