"John Rowland" wrote in message
...
"Paul Corfield" wrote in message
...

With a validator equipped station Travelcard holders
who are "in zone" don't have to swipe their Oyster
card but if you are out of zone you do for the
purposes of calculation of auto ticket extensions.

I see no way that LU can prevent fraud. You can travel
anywhere you like on the system with a one-zone travelcard,
and then when you get to your destination, if the gates
are active, you swipe and have your extension deducted...
if the gates are inactive, you just walk out and you have
no way of getting caught. If any RCI stops you en route
out of your travelcard zone, you just say you are going
to swipe for the extension at your journey's end.

I think I've seen the flaw in my argument. (By the way, all of the following
is supposition since I haven't read any Oyster leaflets.)

Even if your Oyster contains a valid travelcard for the whole journey, you
are still required to swipe at the beginning and end of your journey. If an
RCI catches you halfway through your journey with an unswiped Oyster
containing a valid travelcard for the zone in which you currently are, this
looks suspicious but you would presumably just be warned to swipe in future.
If the RCI catches you are out of your valid zone with an unswiped oyster,
you can then be busted. If you are out of your zone with a swiped Oyster,
then you are obviously intending to swipe on exit and be charged for the
extension... if you don't swipe on exit, you will be charged the maximum
possible extension (to zone 6D or whatever). Therefore the system can not
generally be defrauded in the way I suggested.

But a possible fraud does spring to mind. You have a 2 to 6 Travelcard in
your Oyster. You swipe when you enter at Finchley Road, and again when you
leave at Earls Court. The system doesn't know if you have travelled through
Zone 1 or via Rayners Lane, unless it checks journey times.... can it do
that? Any RCI who caught you in Zone 1 wouldn't be able to bust you, since
you could legitimately be planning to exit at a Zone 1 station and be
debited for the extension.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes