It's all too familiar to subway straphangers: you smack into the turnstile as a message tells you to swipe again.
The Daily News reports that the chance of a MetroCard fail at the turnstile is one in five.
An MTA document outlining the benefits of a new system that would scan without contact put the error rate at 20 percent, the News said.
The document does not explain how the figure was calculated.
Gene Russianoff of the Straphangers Campaign told the News that he thought 20 percent was probably higher than reality, but said the cause of swipe failure is often rider error, for swiping at the wrong speed.
"There's a mystical thing going on," Russianoff said. "You are your card. Some people are type-A personality and swipe too fast. Others go too slowly."
Riders told the News that a swipe-free system sounds like a good idea.
"Sometimes I have to swipe four or five times," said Mason Mekhi, 29. "It's annoying. Especially if the train is downstairs."