Paul Corfield wrote:
Quite why he didn't just use the manual gate validator I do not know -
these work in both entry and exit mode depending on what your card says.
If your last transaction was an entry at a logical location and within a
logical time then the validator will assume you are exiting. It employs
the same logic to determine if you are entering.

What appears logical to the designers of the fare system may not appear
logical to the passenger.

Where can the public obtain a table of these logical locations and
logical times?

On my two brief visits to London since Oyster was launched, I managed to
thoroughly confuse the Oyster system several times. And, although I
really shouldn't be looking over random strangers' shoulders while they
use the ticket machines, I couldn't help but notice that many of their
cards triggered the unresolved journey warning.

I agree with Tristán that this is a problem.
--
David of Broadway
New York, NY, USA