On 25 Jan, 09:39, wrote:
In article , (Roland

Perry) wrote:
In message
,
*at 16:02:48 on Sun, 24 Jan 2010, MIG
remarked:
And someone on a touristy visit is particularly likely to be caught
out, spending short amounts of time at what may turn out to be an OSI,
thus paying maximum fares and cancelling all capping.

I thought I understood Oyster, but those remarks make no sense to
me. If someone is "always touching in and out", how they possibly
be charged more than the daily cap?

In a phrase "unresolved journeys". OSIs can accidentally create them.

Yes; eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

On Jan 25, 10:58*am, MIG wrote:

On 25 Jan, 09:39, wrote:

In article , (Roland
Perry) wrote:

MIG remarked:
And someone on a touristy visit is particularly likely to be caught
out, spending short amounts of time at what may turn out to be an OSI,
thus paying maximum fares and cancelling all capping.

I thought I understood Oyster, but those remarks make no sense to
me. If someone is "always touching in and out", how they possibly
be charged more than the daily cap?

In a phrase "unresolved journeys". OSIs can accidentally create them.

Yes; eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. *Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. *Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

No, that's not correct - whilst the 'unresolved' journey (i.e. the
problematic one that has 'timed-out') does not contribute towards the
cap, other journeys that are successfully resolved *do* contribute
towards the cap. And yes, I have experienced this first hand.

On 25 Jan, 11:36, Mizter T wrote:
On Jan 25, 10:58*am, MIG wrote:





On 25 Jan, 09:39, wrote:

In article , (Roland
Perry) wrote:

MIG remarked:
And someone on a touristy visit is particularly likely to be caught
out, spending short amounts of time at what may turn out to be an OSI,
thus paying maximum fares and cancelling all capping.

I thought I understood Oyster, but those remarks make no sense to
me. If someone is "always touching in and out", how they possibly
be charged more than the daily cap?

In a phrase "unresolved journeys". OSIs can accidentally create them.

Yes; eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. *Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. *Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

No, that's not correct - whilst the 'unresolved' journey (i.e. the
problematic one that has 'timed-out') does not contribute towards the
cap, other journeys that are successfully resolved *do* contribute
towards the cap. And yes, I have experienced this first hand.

Ah right, although reaching a cap on the remaining journeys is
probably that much less likely once the disputed ones don't count
towards it. I was under the impression that if the system felt that
it didn't know what you'd been up to, it wouldn't know which cap to
apply.

On Jan 25, 11:43*am, MIG wrote:

On 25 Jan, 11:36, Mizter T wrote:

On Jan 25, 10:58*am, MIG wrote:

On 25 Jan, 09:39, wrote:
[snip]
In a phrase "unresolved journeys". OSIs can accidentally create them.

Yes; eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. *Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. *Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

No, that's not correct - whilst the 'unresolved' journey (i.e. the
problematic one that has 'timed-out') does not contribute towards the
cap, other journeys that are successfully resolved *do* contribute
towards the cap. And yes, I have experienced this first hand.

Ah right, although reaching a cap on the remaining journeys is
probably that much less likely once the disputed ones don't count
towards it. *I was under the impression that if the system felt that
it didn't know what you'd been up to, it wouldn't know which cap to
apply.

The publicity about touching-in and out is certainly suggestive that
any failure to do so will wreck all capping for the day, though it
doesn't actually explicitly state this. However what appears to happen
in practice is that any unresolved journeys are simply excluded from
the capping calculation.

In message
, at
02:58:18 on Mon, 25 Jan 2010, MIG
remarked:
I thought I understood Oyster, but those remarks make no sense to
me. If someone is "always touching in and out", how they possibly
be charged more than the daily cap?

In a phrase "unresolved journeys". OSIs can accidentally create them.

Yes; eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

That's bonkers! The system has the time I touched back in at Charing
Cross, and can therefore update its expectation of when I could possibly
get to Kew.

On the other hand, if it wants to spot someone getting "too much value
for money", then rather than create two unresolved journeys, it could
split the trip at Charing Cross, and charge two individual journeys.
--
Roland Perry

On Jan 25, 12:56*pm, Roland Perry wrote:

In message
, at
02:58:18 on Mon, 25 Jan 2010, MIG
remarked:

I thought I understood Oyster, but those remarks make no sense to
me. If someone is "always touching in and out", how they possibly
be charged more than the daily cap?

In a phrase "unresolved journeys". OSIs can accidentally create them.

Yes; eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. *Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. *Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

That's bonkers! The system has the time I touched back in at Charing
Cross, and can therefore update its expectation of when I could possibly
get to Kew.

I've a suspicion the system might work on the basis of what the time
was when the (original) journey started - so in this example the card
gets presented to an Oyster pad at Kew which queries what time the
original journey started (i.e. when the first touch-in happened, not
what happened at CX), then checks this against the table of
permissible maximum journey times, then if it's exceeded it presumes
that the pax is in fact ending a different journey where they didn't
touch-in when they began it - voila, two 'max fare' charges end up
being applied (though the mechanism of these charges being applied is
actually that they're deducted at the beginning of a normal journey,
then refunded at the end on exit from the system - though in the case
of the touch-out at Kew it's just taken there and then).


On the other hand, if it wants to spot someone getting "too much value
for money", then rather than create two unresolved journeys, it could
split the trip at Charing Cross, and charge two individual journeys.

I think one possible issue would be that this would require the Oyster
pads and cards to perform calculations beyond their capabilities -
looking back at the recent journey history and then splitting
previously combined journeys, especially complex if there were
multiple OSIs during the journey.

In message
, at
07:32:52 on Mon, 25 Jan 2010, Mizter T remarked:
eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. *Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. *Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

That's bonkers! The system has the time I touched back in at Charing
Cross, and can therefore update its expectation of when I could possibly
get to Kew.

I've a suspicion the system might work on the basis of what the time
was when the (original) journey started

Yes, it probably does. That's why it's bonkers!

- so in this example the card
gets presented to an Oyster pad at Kew which queries what time the
original journey started (i.e. when the first touch-in happened, not
what happened at CX), then checks this against the table of
permissible maximum journey times, then if it's exceeded it presumes
that the pax is in fact ending a different journey where they didn't
touch-in when they began it - voila, two 'max fare' charges end up
being applied (though the mechanism of these charges being applied is
actually that they're deducted at the beginning of a normal journey,
then refunded at the end on exit from the system - though in the case
of the touch-out at Kew it's just taken there and then).

On the other hand, if it wants to spot someone getting "too much value
for money", then rather than create two unresolved journeys, it could
split the trip at Charing Cross, and charge two individual journeys.

I think one possible issue would be that this would require the Oyster
pads and cards to perform calculations beyond their capabilities -
looking back at the recent journey history and then splitting
previously combined journeys, especially complex if there were
multiple OSIs during the journey.

Doesn't it talk to a mainframe?
--
Roland Perry

On Jan 25, 3:43*pm, Roland Perry wrote:

In message
, at
07:32:52 on Mon, 25 Jan 2010, Mizter T remarked:

eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

That's bonkers! The system has the time I touched back in at Charing
Cross, and can therefore update its expectation of when I could possibly
get to Kew.

I've a suspicion the system might work on the basis of what the time
was when the (original) journey started

Yes, it probably does. That's why it's bonkers!


- so in this example the card
gets presented to an Oyster pad at Kew which queries what time the
original journey started (i.e. when the first touch-in happened, not
what happened at CX), then checks this against the table of
permissible maximum journey times, then if it's exceeded it presumes
that the pax is in fact ending a different journey where they didn't
touch-in when they began it - voila, two 'max fare' charges end up
being applied (though the mechanism of these charges being applied is
actually that they're deducted at the beginning of a normal journey,
then refunded at the end on exit from the system - though in the case
of the touch-out at Kew it's just taken there and then).

On the other hand, if it wants to spot someone getting "too much value
for money", then rather than create two unresolved journeys, it could
split the trip at Charing Cross, and charge two individual journeys.

I think one possible issue would be that this would require the Oyster
pads and cards to perform calculations beyond their capabilities -
looking back at the recent journey history and then splitting
previously combined journeys, especially complex if there were
multiple OSIs during the journey.

Doesn't it talk to a mainframe?

No, not to perform that calculation - it's done there and then,
without any need to talk to the central database to work it out. None
of the transactions between card and Oyster pad involve live
communication with the database, which makes a lot of sense for
several reasons.

That's not to say that Oyster pads at stations aren't all hooked up to
the system, but that's not the same thing as live database look-ups
happening whenever an Oyster card is presented.

I dare say that in this and other discussions we're making a whole
host of dodgy and inaccurate assumptions, are not taking several
important factors into account, and are perhaps guilty of leaping to
conclusions - I can imagine someone who understood the guts of the
system grimacing as they read it! Nonetheless, a function that's
supposed to make life smoother and more seamless for pax - that of out-
of-station interchanges (OSIs) - does often appear to be at the root
of the problems that people encounter with Oyster.

On 25 Jan, 15:59, Mizter T wrote:
On Jan 25, 3:43*pm, Roland Perry wrote:





In message
, at
07:32:52 on Mon, 25 Jan 2010, Mizter T remarked:

eg you go from Greenwich to Charing Cross (with a change at
London Bridge), take your snaps of Nelson, then go into the
Underground for a trip to Kew Gardens. Because Charing Cross is an
OSI, probably with a long timeout, the whole thing ends up as a single
journey which could go beyond the time limit, leaving you with an
unresolved journey and an unstarted journey at Kew, both of which are
charged at maximum. Once you've got an unresolved journey (I'm pretty
sure) all capping goes out of the window.

That's bonkers! The system has the time I touched back in at Charing
Cross, and can therefore update its expectation of when I could possibly
get to Kew.

I've a suspicion the system might work on the basis of what the time
was when the (original) journey started

Yes, it probably does. That's why it's bonkers!

- so in this example the card
gets presented to an Oyster pad at Kew which queries what time the
original journey started (i.e. when the first touch-in happened, not
what happened at CX), then checks this against the table of
permissible maximum journey times, then if it's exceeded it presumes
that the pax is in fact ending a different journey where they didn't
touch-in when they began it - voila, two 'max fare' charges end up
being applied (though the mechanism of these charges being applied is
actually that they're deducted at the beginning of a normal journey,
then refunded at the end on exit from the system - though in the case
of the touch-out at Kew it's just taken there and then).

On the other hand, if it wants to spot someone getting "too much value
for money", then rather than create two unresolved journeys, it could
split the trip at Charing Cross, and charge two individual journeys.

I think one possible issue would be that this would require the Oyster
pads and cards to perform calculations beyond their capabilities -
looking back at the recent journey history and then splitting
previously combined journeys, especially complex if there were
multiple OSIs during the journey.

Doesn't it talk to a mainframe?

No, not to perform that calculation - it's done there and then,
without any need to talk to the central database to work it out. None
of the transactions between card and Oyster pad involve live
communication with the database, which makes a lot of sense for
several reasons.

That's not to say that Oyster pads at stations aren't all hooked up to
the system, but that's not the same thing as live database look-ups
happening whenever an Oyster card is presented.

I dare say that in this and other discussions we're making a whole
host of dodgy and inaccurate assumptions, are not taking several
important factors into account, and are perhaps guilty of leaping to
conclusions - I can imagine someone who understood the guts of the
system grimacing as they read it! Nonetheless, a function that's
supposed to make life smoother and more seamless for pax - that of out-
of-station interchanges (OSIs) - does often appear to be at the root
of the problems that people encounter with Oyster.

The bottom line, going back to the original question, is that the
stress, uncertainty and risk of being out of pocket can be avoided
with a day travelcard, as long as they are available. I'd like to
hope that they will continue to be available till Oyster can genuinely
offer a comprehensive, stress-free, risk-free replacement for them.

And there's never been any proper reason for refusing to put day
travelcards on Oyster anyway. It's extra money up front, and the
punter still buys into the Oyster system.

Instead of charging an uncapped maximum single fare for unresolved
journeys, the system could charge a day travelcard instead, and let
the punter use it as such thereafter.

"MIG" wrote
And there's never been any proper reason for refusing to put day
travelcards on Oyster anyway. It's extra money up front, and the punter
still buys into the Oyster system.
Instead of charging an uncapped maximum single fare for unresolved
journeys, the system could charge a day travelcard instead, and let the
punter use it as such thereafter.

That sounds like a very good idea. Is there any technical reason why it
can't be done?