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There's a slight perverse incentive in that not having access to Contactless history makes it harder for the customer to see overcharging and to make claims fo

There's a slight perverse incentive in that not having access to Contactless history makes it harder for the customer to see overcharging and to make claims for a refund.

avianlyric 2y ago
The TfL contactless system doesn’t generally overcharge, as long as you properly tap-in and tap-out. The system as a whole seems to be designed to prevent overcharging at all costs. In situations where is ambiguous what you should be charged (there’s a number of interesting edge-cases), the system always charges you the lowest possible amount. Even in the event of user error (such as forgetting to tap-out), the system does it best the guess what you did, such as looking at your history and assuming you meant to tapped out at a station you normally use, or looking for a station where the gates where left open (due to a major event, overcrowding concern, evacuation etc), and assuming you left the system there. The contactless system is substantially more capable for handling these issues correctly, and generally better at charging less, than the older Oyster system.
- reddalo 2y ago
  >In situations where is ambiguous what you should be charged (there’s a number of interesting edge-cases) I'm very curious to know more about those edge cases.
  - avianlyric 2y ago
    There are some interesting issues with the old oyster system when handling certain routes that involve out of station interchanges. Out of station interchanges effect make two sets of barriers behave like they’re part of the same physical station, allowing you to temporarily exit the system, re-enter, but only get charged once, as if you never exited the system at all. On the old oyster system this plays very badly with how the system handles you tapping in and out at the same station, at the start and end of a single journey. The Oyster systems assumes that you’ve made two trips, and not tapped out one way, and not tapped in the other way, and thus charges you two maximum fairs. Normally this isn’t an issue, but with out-of-station interchanges, it’s possible for you make a journey, leave the station, re-enter the station 20-30mins later, for your return journey (say you went to pick something up, and then went straight home), get caught within the out-of-station interchange, which effectively connects your return journey with your outbound journey. On the Oyster system, the out-of-station interchange is implemented by the re-entry barrier basically updating your card so it looks like you never left the system at all, as a consequence, when you tap out at your home station, the tap-out barrier thinks you’ve made two trips without properly tapping in and out, and charges you two maximum fairs. With the contactless system, every single tap in and out is recorded by the barriers in their backend system, and an end of day batch system then looks at all of your tap ins and outs, and computes your final fair. Because it can see every single tap, it’s capable of recognising that you made two legitimate journeys, that shouldn’t be linked to by the out of station interchange, and thus charge you two correct fairs. Unlike the Oyster system, which has to make fair charging decisions at each tap, and due to limited memory on the card, can’t accurately track every single tap, as a result it has to be more aggressive in it fair calculation approach, otherwise it would be trivial to exploit its limitations to defraud TfL. Although even the Oyster system will try and correct these issues. There are batch jobs that run on all the uploaded tap data collected by the barriers themselves, and those jobs do their best to try and spot errors like this, and perform automatic refunds. But it harder to perform those refunds because somehow the system has to the get the data on to the physical Oyster card, which uploading the patch into the barriers the system thinks you’re likely to use, so your card can be patched on the tap there.
- lol768 2y ago
  > The TfL contactless system doesn’t generally overcharge, as long as you properly tap-in and tap-out. > The contactless system is substantially more capable for handling these issues correctly, and generally better at charging less, than the older Oyster system. Nonsense, everyone with a railcard is routinely overcharged, by design.
  - bmsleight_ 2y ago
    Any facts to back up this assumption ? "TfL said the amount refunded equated to less than 0.001% of annual fare £3bn revenue collected via pay as you go with contactless."
    - lol768 2y ago
      It's not an assumption. If you have a railcard, you cannot associate it with a contactless card. That's just not a supported task. Therefore if you travel off-peak, you will be charged more than you would if you had used an Oyster card because you will be charged the public rate instead of the discounted fare you were actually entitled to pay. It's very simple. https://tfl.gov.uk/fares/free-and-discounted-travel/national-railcard-discount https://tfl.gov.uk/fares/free-and-discounted-travel/national...
      - switch007 2y ago
        Another reason to use Oyster (in addition to the fact that people can access their Oyster history currently, it's just Contactless that can't AIUI)
  - avianlyric 2y ago
    You’re talking about something completely different. The fact that the contactless system doesn’t support railcards doesn’t change the fact that it’s much better at performing the core task of computing people’s movements through TfLs systems, and charging the correct amount. Oyster system is fundamentally limited by its use of stored values on the physical cards, making it hard for the system to correctly issues retroactive refunds. TfL does its best to automate this, if you regularly use the same station, buts it’s an imperfect system. TfL have long acknowledged the issue with railcards, and not supporting them on contactless is hardly “by design”. It’s substantially harder to support railcards, and perform correct enforcement of them, with contactless cards. There’s no way of meaningfully marking a contactless card as being paired with a railcard, which would allow ticket inspectors to actually know that when performing enforcement. It would be come trivial for people to defraud TfL using railcards, if there was no mechanism for allowing spot checks on people travelling. To make the argument that not supporting railcards is “by design”, you also need to explain why TfL accept railcards on the Oyster system. TfL are under no obligation whatsoever to support national railcards. So if the lack of support for railcards on contactless was a revenue maximisation choice, why don’t they just get rid of the railcard discount entirely?
- switch007 2y ago
  I know it's designed quite well and operates mostly without error but TfL as a whole is not perfect > as long as you properly tap-in and tap-out And this is far from straight forward everywhere. E.g. Waterloo & City at Waterloo and its lack of barriers Some believe Waterloo is actually long-standing money-maker for TfL ... > The system as a whole seems to be designed to prevent overcharging at all costs But not the physical UX
  - avianlyric 2y ago
    > And this is far from straight forward everywhere. E.g. Waterloo & City at Waterloo and its lack of barriers Lack of barriers is to prevent overcrowding, and maximise passenger flow at one of the busiest stations in London. If you use that link regularly, then you don’t actually need to tap out at all. The contactless system will spot the missing tap-out, and automatically add a virtual tap-out for you at the end of the day. > But not the physical UX Including the physical UX. Lack of barriers is the exception, not the rule. If the physical UX wasn’t designed to prevent overcharging, then TfL wouldn’t bother installing so many purple interchange readers around the system, and keep reminding people to use them. The only purpose of those readers is to allow people to get a lower fair by demonstrating they’ve avoided zone 1.
- grues-dinner 2y ago
  > In situations where is ambiguous what you should be charged (there’s a number of interesting edge-cases), the system always charges you the lowest possible amount. Not always, you can still be charged a Zone 1 fare if you don't use a pink route validator to prove that you went around the outside of Zone 1.

There's a slight perverse incentive in that not having access to Contactless history makes it harder for the customer to see overcharging and to make claims for a refund.

avianlyric 2y ago

The TfL contactless system doesn’t generally overcharge, as long as you properly tap-in and tap-out. The system as a whole seems to be designed to prevent overcharging at all costs. In situations where is ambiguous what you should be charged (there’s a number of interesting edge-cases), the system always charges you the lowest possible amount. Even in the event of user error (such as forgetting to tap-out), the system does it best the guess what you did, such as looking at your history and assuming you meant to tapped out at a station you normally use, or looking for a station where the gates where left open (due to a major event, overcrowding concern, evacuation etc), and assuming you left the system there. The contactless system is substantially more capable for handling these issues correctly, and generally better at charging less, than the older Oyster system.

reddalo 2y ago
>In situations where is ambiguous what you should be charged (there’s a number of interesting edge-cases) I'm very curious to know more about those edge cases.
- avianlyric 2y ago
  There are some interesting issues with the old oyster system when handling certain routes that involve out of station interchanges. Out of station interchanges effect make two sets of barriers behave like they’re part of the same physical station, allowing you to temporarily exit the system, re-enter, but only get charged once, as if you never exited the system at all. On the old oyster system this plays very badly with how the system handles you tapping in and out at the same station, at the start and end of a single journey. The Oyster systems assumes that you’ve made two trips, and not tapped out one way, and not tapped in the other way, and thus charges you two maximum fairs. Normally this isn’t an issue, but with out-of-station interchanges, it’s possible for you make a journey, leave the station, re-enter the station 20-30mins later, for your return journey (say you went to pick something up, and then went straight home), get caught within the out-of-station interchange, which effectively connects your return journey with your outbound journey. On the Oyster system, the out-of-station interchange is implemented by the re-entry barrier basically updating your card so it looks like you never left the system at all, as a consequence, when you tap out at your home station, the tap-out barrier thinks you’ve made two trips without properly tapping in and out, and charges you two maximum fairs. With the contactless system, every single tap in and out is recorded by the barriers in their backend system, and an end of day batch system then looks at all of your tap ins and outs, and computes your final fair. Because it can see every single tap, it’s capable of recognising that you made two legitimate journeys, that shouldn’t be linked to by the out of station interchange, and thus charge you two correct fairs. Unlike the Oyster system, which has to make fair charging decisions at each tap, and due to limited memory on the card, can’t accurately track every single tap, as a result it has to be more aggressive in it fair calculation approach, otherwise it would be trivial to exploit its limitations to defraud TfL. Although even the Oyster system will try and correct these issues. There are batch jobs that run on all the uploaded tap data collected by the barriers themselves, and those jobs do their best to try and spot errors like this, and perform automatic refunds. But it harder to perform those refunds because somehow the system has to the get the data on to the physical Oyster card, which uploading the patch into the barriers the system thinks you’re likely to use, so your card can be patched on the tap there.
lol768 2y ago
> The TfL contactless system doesn’t generally overcharge, as long as you properly tap-in and tap-out. > The contactless system is substantially more capable for handling these issues correctly, and generally better at charging less, than the older Oyster system. Nonsense, everyone with a railcard is routinely overcharged, by design.
- bmsleight_ 2y ago
  Any facts to back up this assumption ? "TfL said the amount refunded equated to less than 0.001% of annual fare £3bn revenue collected via pay as you go with contactless."
  - lol768 2y ago
    It's not an assumption. If you have a railcard, you cannot associate it with a contactless card. That's just not a supported task. Therefore if you travel off-peak, you will be charged more than you would if you had used an Oyster card because you will be charged the public rate instead of the discounted fare you were actually entitled to pay. It's very simple. https://tfl.gov.uk/fares/free-and-discounted-travel/national-railcard-discount https://tfl.gov.uk/fares/free-and-discounted-travel/national...
    - switch007 2y ago
      Another reason to use Oyster (in addition to the fact that people can access their Oyster history currently, it's just Contactless that can't AIUI)
- avianlyric 2y ago
  You’re talking about something completely different. The fact that the contactless system doesn’t support railcards doesn’t change the fact that it’s much better at performing the core task of computing people’s movements through TfLs systems, and charging the correct amount. Oyster system is fundamentally limited by its use of stored values on the physical cards, making it hard for the system to correctly issues retroactive refunds. TfL does its best to automate this, if you regularly use the same station, buts it’s an imperfect system. TfL have long acknowledged the issue with railcards, and not supporting them on contactless is hardly “by design”. It’s substantially harder to support railcards, and perform correct enforcement of them, with contactless cards. There’s no way of meaningfully marking a contactless card as being paired with a railcard, which would allow ticket inspectors to actually know that when performing enforcement. It would be come trivial for people to defraud TfL using railcards, if there was no mechanism for allowing spot checks on people travelling. To make the argument that not supporting railcards is “by design”, you also need to explain why TfL accept railcards on the Oyster system. TfL are under no obligation whatsoever to support national railcards. So if the lack of support for railcards on contactless was a revenue maximisation choice, why don’t they just get rid of the railcard discount entirely?
switch007 2y ago
I know it's designed quite well and operates mostly without error but TfL as a whole is not perfect > as long as you properly tap-in and tap-out And this is far from straight forward everywhere. E.g. Waterloo & City at Waterloo and its lack of barriers Some believe Waterloo is actually long-standing money-maker for TfL ... > The system as a whole seems to be designed to prevent overcharging at all costs But not the physical UX
- avianlyric 2y ago
  > And this is far from straight forward everywhere. E.g. Waterloo & City at Waterloo and its lack of barriers Lack of barriers is to prevent overcrowding, and maximise passenger flow at one of the busiest stations in London. If you use that link regularly, then you don’t actually need to tap out at all. The contactless system will spot the missing tap-out, and automatically add a virtual tap-out for you at the end of the day. > But not the physical UX Including the physical UX. Lack of barriers is the exception, not the rule. If the physical UX wasn’t designed to prevent overcharging, then TfL wouldn’t bother installing so many purple interchange readers around the system, and keep reminding people to use them. The only purpose of those readers is to allow people to get a lower fair by demonstrating they’ve avoided zone 1.
grues-dinner 2y ago
> In situations where is ambiguous what you should be charged (there’s a number of interesting edge-cases), the system always charges you the lowest possible amount. Not always, you can still be charged a Zone 1 fare if you don't use a pink route validator to prove that you went around the outside of Zone 1.