I was at Stratford Station today and noticed something very
distressing: the lack of a second gateline between the Central Line/NR
platforms and the Jubilee Line platforms means that Pre-Pay users who
don't see the validators on the Central Line platforms (there aren't
very many and they're not easy to find) will mis-validate when they
try to pass the gateline to get to the Jubilee Line. Even stranger is
that there appears to be no obvious way to reach the Jubilee Line
platforms from the street without passing the entrance gateline and
the Jubilee Line and mis-validating again.

Is this a known issue or has no one simply noticed?

Brad