On Mon, 11 May 2009 03:06:23 -0700 (PDT),
Mizter T wrote:

On May 11, 9:10*am, Tim Woodall wrote:


you can ask the Oyster help desk for a PDF of all the
journeys you've done in the past three months, which won't have any
gaps in it (unlike the online journey history).


That's very useful to know. Thanks. I'll do that.

I keep a detailed spreadsheet of my oyster PAYG expenses because it's
(currently) slightly cheaper for me to use PAYG than a Watford Junction
- London Euston season. (Prior to this years vicious price hikes from
Watford Junction it was very much cheaper). I don't necessarly expect
that this state of affairs will last and I want to make sure I swap back
to a season ticket as/when it makes financial sense.

But it's not trivially easy to calculate because, for example, my
occasional Watford Junction-Zone 1 rather than WJ-Euston cost an extra
50p currently but would cost 1.60 extra if I had a season ticket. So my
spreadsheet is setup with some quite complicated rules to try and
estimate my annual expenditure. Missing entries/exits, of course,
completely break those calculations.


I know for a fact that occasionally exits can fail to register (I
believe it has happened on entry as well but I can only be 99% sure).
It's happened to my girlfriend the very first journey she made on PAYG.
I was explaining to her how it all worked and how you had to make sure
you always touched in and out. On that particular journey she exited via
the barriers at Watford Junction - I watched her open them with her
oyster card and walk through - but she ended up with an unresolved
journey. And because she's not that often in London and credits can only
be put back onto your card when you use an oyster gate, LUL "stole" that
money because she couldn't get her credit back within 8 weeks.

I have never come across this issue before. It's worth noting that
when you touch-in or touch-out on a gate (or standalone Oyster reader)
a transaction occurs there and then between the validator and the
smartcard - this means that the fare is debited from the card
immediately, i.e. without any recourse to the Oyster central database
(which just keeps tabs on all the transactions).

In this particular instance I'm not sure what happened - perhaps the
validators on the gates at Watford Jn were not functioning correctly
(it was early days of PAYG at Watford Jn) and so let her out but
somehow didn't properly conduct the transaction with her Oyster card.
Otherwise I wonder if she inadvertently walked through on someone
else's ticket, though from your account that sounds unlikely. The
other thing that comes to mind was whether this was a problem of the
whole journey 'timing out' - which could perhaps happen if she had
started the journey from a Tube station, then made the interchange at
Euston, then travelled on to Watford Jn and the total time of the
whole journey was over 2 hours (this limit has now been raised to 2
1/2 hours, and is in the process of being changed again so that it
reflects the distance a passenger has travelled).

In this particular case I'm 100% sure it was a failure somewhere in the
Oyster system because I was watching exactly what she did. I cannot be
100% certain that there wasn't a message displayed on the barrier as
well because I was standing outside the barrier line but I can be sure
that her card opened the barrier. She was standing at the barrier
wondering what to do with her card - I said "touch it on the yellow
pad." The gates opened, she walked though and said "He, he. It works!"
(On this particular day the card was brand new in its own wallet away
from all other cards so it cannot even be some freak interference. IIRC
on the way in at Euston she came through the manual barrier with me so
if it had been a missing entry then I could have better understood what
might have gone wrong)

I've had one case where I think I had a missed entry. Normally I use the
manual gate because I have my Brompton with me but I had a failure on a
day when I didn't have my bike. If I don't have my bike then I
invariably use the automatic gates but I cannot be 100% sure that either
the gates weren't all open or I didn't use the manual gate anyway. If
the gates were all open then I'm not exprienced enough at using them to
have necessarily been looking in the right direction to see any error
message if the card didn't register for any reason. (IIRC I've had one
other missed entry at Euston - I noticed when I exited at Watford
Junction and it registered as an entry but I'll assume that that was
user error. I couldn't be bothered to claim back the extra 50p it cost
me)

I've also had a case where it has opened the gates for me but beeped
ominously and said "seek assistance"[1]. (Can't remember where but it
was a station I'd never used before). When I asked at the window they
said "Don't worry, it does that sometimes" but they did check my journey
history there and then and the exit had registered properly so maybe it
was something I did...

[1] This might not have been the exact message, I cannot remember now
but it was something like that.

One thing that would be very useful is a reader somewhere that just
displays whether the card thinks it is "in" or "out" of the system.
I've had times when I've been sitting on the train at Euston and thought
"Did I touch in?" I always have but there's no way to actually check
AFAIAA. Or sometimes I've been distracted while touching in or out and
not actually managed to read the message on the display before it has
gone again.

Tim.


--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.

http://www.woodall.me.uk/