Remember to tap in and tap out

In the beginning there was only 1 sign. The sign (on the left) that said:
Remember to tap in and tap out. Maximum fare will be charged if you forget to tap out on exit.



Then they discovered that passengers were too obedient!
They were tapping in and tapping out as asked, because the sign says maximum fares will be charged. But at the wrong timing.

Then they came out with a big NOTICE.