What happens to ticket barrier data?

[radamfi]

What happens to ticket barrier data?

Presumably the origin, destination, ticket number, start date, end date, ticket issuing office, fare etc. from tickets put through barriers are stored in some database. Do train companies make any use of this data, for example for patronage estimation?

Can this data be used by the police or in a court of law, for example to prove that a person was at a particular location at a particular time?

 

[wintonian]

Usage stats (inc when the station is busy or quite) and what stations from/ to the ticket is for and railcard/ child stats I would suspect and in some ways the data is likely to be more accurate than the figures gained from sales data.

I suspect that only the CCTV would prove that a passenger was at a certain place at a certain time as most tickets don't carry the users name those that do I doubt are encoded in to the mag-strip though seasons may be, but the fact that one was used wouldn't be enough evidence for a police investigation.

Interesting question, is there any data not immediately obvious?

 

[radamfi]

I suspect that only the CCTV would prove that a passenger was at a certain place at a certain time as most tickets don't carry the users name those that do I doubt are encoded in to the mag-strip though seasons may be, but the fact that one was used wouldn't be enough evidence for a police investigation.

Tickets bought using a credit card could presumably be traced to the credit card owner by reconciling the ticket number with credit card payments.

 

[wintonian]

But do the barriers actually collect individual ticket numbers, I can see how that would be useful to the police but why would a TOC wish to record them?

 

[radamfi]

But do the barriers actually collect individual ticket numbers, I can see how that would be useful to the police but why would a TOC wish to record them?

Barriers usually 'remember' what tickets have been put through. If you try and put a ticket previously used in that barrier it is usually rejected. Presumably there is a limited amount of data that can be stored in the magnetic strip given that the technology is so old. Therefore (I'm guessing) that all ticket numbers used in that barrier are stored somewhere.

 

[me123]

...most tickets don't carry the users name those that do I doubt are encoded in to the mag-strip though seasons may be...

Seasons are likely to have the photocard number on the magnetic strip, I would imagine. This may allow a season ticket to be traced back to the holder, or at least to the ticket office where it was purchased, if it's eaten up by a machine. (I'm just guessing, but it would be an easy way to find such a ticket).

 

[wintonian]

Hmm I getting a little worried about all this limited space were using up on the mag strip - how much data can it hold? Any guesses?

 

[dan_atki]

Barriers usually 'remember' what tickets have been put through. If you try and put a ticket previously used in that barrier it is usually rejected. Presumably there is a limited amount of data that can be stored in the magnetic strip given that the technology is so old. Therefore (I'm guessing) that all ticket numbers used in that barrier are stored somewhere.

I don't think the barriers are quite that sophisticated! I believe the barrier modifies the data on the strip so the ticket knows it has been through that barrier already, rather than the barrier knowing. Therefore, the next time the ticket is inserted, the ticket flags the barrier rather than the other way around.

There is a reason I suspect it is this way around. Once I had two 7-day Travelcards for successive periods as part of a course I was on in London. (What was more amazing is this was AFTER 7-day tickets had all been transfered to Oyster and these were TfL paper tickets). One evening in the first week, I mistakenly put the wrong ticket (that for the second week) into the barrier, which obviously wouldn't work.

The ticket then proceeded to fail completely, opening no barrier at all, even after the start date had passed. In the end, I had great difficulty getting it replaced to a usable ticket as 7 day Travelcards were all on Oyster now, until some very kind lady at Charing Cross managed to do it, bypassing the system somehow!

Admittedly, this is what LU barriers do, but I suspect NR ones operate in the same manner.

Seasons are likely to have the photocard number on the magnetic strip, I would imagine. This may allow a season ticket to be traced back to the holder, or at least to the ticket office where it was purchased, if it's eaten up by a machine. (I'm just guessing, but it would be an easy way to find such a ticket).

I suspect the same, now photocard numbers can be inputted so they are printed on the ticket. This way if, through excessive usage say, the print wears down on the top of the ticket, it is possible (although it is quite unreliable) to put a TIS into a mode and swipe the ticket to obtain the data from it, in a readable form.

On a different note, station usage figures are not calculated by using barrier data. Obviously, stations that do not have barriers would not work. In order to make the system uniform, LENNON (the software used for ticket analysis) uses ticket issues to calculate station entries (the origins on tickets) and exits (the destinations on tickets). Seasons and rovers are slightly more complicated - I suspect there is a 'usage' factor for seasons, and rovers are ignored completely.

 

[wintonian]

I wasn't really thinking about LENNON data, more that it gives individual TOC's their own additional data source to use for stations that use barriers.

 

[barrykas]

The magstripe on a standard ticket holds a massive...192 bits of data, broken down as follows:

• Header : 16 bits
• Rail Settlement Plan Data : 72 bits
• London Underground Data : 80 bits
• Checksum : 8 bits
• Trailer : 16 bits

The full spec can be found on the password protected bit of the ATOC website.

Cheers,

Barry

 

[wibble]

For each station, the gates will record:

- The date and time a ticket was put through a gate
- The mode the gate was in (e.g. exit mode)
- Whether the ticket is an Adult or Child one
- Whether the ticket was accepted or rejected
- A reject code for the ticket (Reject code 0 = ticket valid)
- Whether the tickets been recoded
- Whether the ticket was captured by the gate (i.e. at the ticket's destination)
- The ticket's Origin, Desintation, Route code, ticket type and any discount

It also records a load of LU data which is meaningless to a TOC.

The gatelines do not record a ticket number so there is no way of associating ticket use to an individual.

Oyster is different as you can follow an individual Oystercard around Zones 1-6.

 

[radamfi]

Some barriers allow you to break your journey. For example, on a ticket from Southampton to London you might be able to break journey at every barriered station on route without the ticket having to be passed manually. So I don't see how all that information could be stored on the ticket in 72 bits.

 

[wibble]

What happens to ticket barrier data?

Not a lot!

Presumably the origin, destination, ticket number, start date, end date, ticket issuing office, fare etc. from tickets put through barriers are stored in some database.

see above

Do train companies make any use of this data, for example for patronage estimation?

Yes - this is helpful in planning for big events as you get to see the flow of people through a station over a period of time. e.g. it could help to decide how many gates are in entry or exit mode when a large event is on.

Can this data be used by the police or in a court of law, for example to prove that a person was at a particular location at a particular time?

Paper tickets can't as the gates only store basic data as it appears on the front of the ticket. Smartcards/Oyster are different as each card has a unique number which you can follow around a network.
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Some barriers allow you to break your journey. For example, on a ticket from Southampton to London you might be able to break journey at every barriered station on route without the ticket having to be passed manually. So I don't see how all that information could be stored on the ticket in 72 bits.

Break of journey data is held within the gate's programming and not on the ticket itself.

 

[radamfi]

Break of journey data is held within the gate's programming and not on the ticket itself.

What I mean is, suppose you had a ticket from Honiton to Berrylands. You get off at Basingstoke, go through the barriers and go back into the station an hour later and get the train to Woking. Then you leave Woking station and then renter an hour later. Then do the same at Weybridge and Walton.

If you then do the same at Surbiton, how does the barrier know that you had or hadn't passed through all those other barriers? There presumably isn't enough information on the ticket to record the passing through all those barriers. But if you attempt to do the same trip the next day with the same ticket, the Basingstoke barrier would reject the ticket.

 

[yorkie]

If you still have privacy concerns, buy paper tickets (not Oyster) bought with cash.

 

[wibble]

What I mean is, suppose you had a ticket from Honiton to Berrylands. You get off at Basingstoke, go through the barriers and go back into the station an hour later and get the train to Woking. Then you leave Woking station and then renter an hour later. Then do the same at Weybridge and Walton.

If you then do the same at Surbiton, how does the barrier know that you had or hadn't passed through all those other barriers? There presumably isn't enough information on the ticket to record the passing through all those barriers. But if you attempt to do the same trip the next day with the same ticket, the Basingstoke barrier would reject the ticket.

To be honest, I've never tried it! The ticket may be re-coded to show that you've made a break of journey and prevent you from doing another one. Obviously, this wouldn't apply to season tickets as they allow multiple breaks of journey along the line of route.
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If you still have privacy concerns, buy paper tickets (not Oyster) bought with cash.

And pay more for the privilege!

 

[yorkie]

And pay more for the privilege!

Depends on the journeys you make.

 

[radamfi]

If there are over 2500 stations in the country then recording the name of a station on the ticket must require at least 12 bits:

(2 to the power of 11 is 2048, 2 to the power of 12 is 4096)

Therefore, if a magnetic ticket needs to hold only station names, it can hold no more than 6 (72/12=6). Obviously when the other data is taken into account, that would be 5 or less.

So, no more than 3 break of journey stations can be stored in the ticket if you account for the origin and destination.

 

[yorkie]

Each station has a unique 3 letter code, but many tickets are issued to groups of stations e.g. London Terminals, Birmingham Stations and other destinations that do not have 3-letter codes. All locations have a 4 digit code. e.g. Boundary Zone 6 to Southend Stns is 0072 to 0411. Neither has a 3 digit code and neither is a 'station'.

 

[wibble]

If there are over 2500 stations in the country then recording the name of a station on the ticket must require at least 12 bits:

(2 to the power of 11 is 2048, 2 to the power of 12 is 4096)

Therefore, if a magnetic ticket needs to hold only station names, it can hold no more than 6 (72/12=6). Obviously when the other data is taken into account, that would be 5 or less.

So, no more than 3 break of journey stations can be stored in the ticket if you account for the origin and destination.

The station name is only recorded on the ticket as the NLC code which is only 4 characters long.

To be honest, I don't think there is any recoding of the ticket for break of journey, so you might be ok. The only re-coding the gates make are for passback (i.e. to prevent one person exiting, passing the ticket to someone else on the other sie of the gates for them to use.)

As the gates were designed to LUL's specification, their tickets were single journey or season ticket only. There was no need for them to specify break of journey on a single ticket.

 

[radamfi]

The station name is only recorded on the ticket as the NLC code which is only 4 characters long.

So it probably takes at least 4 bits to store each character if each character of the NLC code is stored on the ticket separately (2 to the power of 3 is 8 and 2 to the power of 4 is 16. You need 10 possible combinations of 0s and 1s to make a binary representation of the numbers 0 to 9). Which would make it 16 bits per station.

 

[mickey]

The magstripe on a standard ticket holds a massive...192 bits of data

Wow, that's huge compared with the 20 characters I was once told!

Anyway, my addition is that collecting usage stats from barriers would be pointless because most stations allow luddites to use manual barriers without insisting they use the gates. Unless station staff then feed the tickets through themselves (no chance!) those tickets go unrecorded. And if you look at any of the Liverpool stations on any given day you'll see quite how many people this involves.

On a related note (though don't get me started!) usage statistics even using printed ticket data are next to useless, given how many people use zonal or other season tickets - and especially given how many ticket issuing staff completely ignore what you ask them and issue a ticket to alternative stations if the price is the same and they think it's easier.

 

[Ivo]

So does each separate barrier have its own database or are they all linked to one station, regional, TOC or even national database? How much data can any one barrier hold (more than 24 bytes I assume? )? Similarly, how much data can Oyster cards hold?

 

[Greenback]

Wow, that's huge compared with the 20 characters I was once told!

Anyway, my addition is that collecting usage stats from barriers would be pointless because most stations allow luddites to use manual barriers without insisting they use the gates. Unless station staff then feed the tickets through themselves (no chance!) those tickets go unrecorded. And if you look at any of the Liverpool stations on any given day you'll see quite how many people this involves.

On a related note (though don't get me started!) usage statistics even using printed ticket data are next to useless, given how many people use zonal or other season tickets - and especially given how many ticket issuing staff completely ignore what you ask them and issue a ticket to alternative stations if the price is the same and they think it's easier.

I'm in full agreement about the usage stats, but I;m a vit confused about the last bit of your post! Can you give some examples?

 

[ralphchadkirk]

you then do the same at Surbiton, how does the barrier know that you had or hadn't passed through all those other barriers? There presumably isn't enough information on the ticket to record the passing through all those barriers.

They don't, and they don't need to. All the gates need to know is whether a break of journey is permitted there and on that ticket.

 

[yorkie]

Wow, that's huge compared with the 20 characters I was once told!

I wouldn't say that; it's only 4 more characters! More of an approximation I'd say (also bearing in mind that the figure of 192 bits, or 24 characters, includes things like the checksum)

 

[rail-britain]

What happens to ticket barrier data?

It is stored for up to 7 days on the terminal
Once downloaded it can be stored for up to 28 days
After 56 days the data MUST be deleted
The summary may be retained for up to 5 years

Do train companies make any use of this data, for example for patronage estimation?

It is used to compare expected revenue with actual revenue
The shortfall can then be submitted for a claim back on the Rail Settelement Plan, however so far no TOC has submitted such a claim suggesting the number of tickets is below that expected
This is possible as many passengers pass the barriers, showing their tickets but they are not retained

Can this data be used by the police or in a court of law, for example to prove that a person was at a particular location at a particular time?

It is possible, but could be easily dismissed in a Scottish Court as the ticket passes out of visual range inside the machine
However it was quite a unique ticket, easily recognised, then it is possible
There are other better methods that can be used

 

[radamfi]

They don't, and they don't need to. All the gates need to know is whether a break of journey is permitted there and on that ticket.

If nothing is written to the ticket on break of journey then there would be nothing to stop a passenger reusing a ticket at all intermediate barriers on route. Also, in my example from Honiton to Berrylands, someone could go through the barrier at Basingstoke and then later on at Salisbury even though Salisbury is supposed to be before Basingstoke.
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It is stored for up to 7 days on the terminal
Once downloaded it can be stored for up to 28 days
After 56 days the data MUST be deleted
The summary may be retained for up to 5 years

Why would there be a time limit on keeping data if, as wibble says, the ticket number is not recorded and therefore there is no connection to the ticket user?

 

[ralphchadkirk]

Yes, but how would they get to Basingstoke before Salisbury?!

 

[radamfi]

Yes, but how would they get to Basingstoke before Salisbury?!

If they were using the ticket again.