Paper Travel Cards Early 90s

[Deleted]

Seeing talk about old style tickets elsewhere on the board has reminded me of something I have wanted to ask.    I remember being told a story about old style weekly travel cards (Magnetic strip on back) you used to buy in newsagent that were stamped with the start / end date.  I was told that you could get away with using them longer than the dates on the front as the 7 days only started from the first time you used one on a ticket barrier so would carry on working until the time had passed.

Was this a tale or true?

[snoggle]

Feb 20, 2019 20:43:12 GMT @dannyb said:

Seeing talk about old style tickets elsewhere on the board has reminded me of something I have wanted to ask.    I remember being told a story about old style weekly travel cards (Magnetic strip on back) you used to buy in newsagent that were stamped with the start / end date.  I was told that you could get away with using them longer than the dates on the front as the 7 days only started from the first time you used one on a ticket barrier so would carry on working until the time had passed.

Was this a tale or true?

It is true. The mag stripe stock for Pass agents (as they were called back then) was partially pre-encoded but not the dates. Agents only had date stamps so would stamp the start and end dates on the front. The encoding was only updated when first presented at a ticket gate. The coding had the period of the ticket but the start and end dates were only updated when first presented to a ticket gate. Therefore if an agent issued ticket was not presented to a ticket gate on the first day of validity you got a mismatch. IIRC Pass Agents were later issued with machines that could print and encode tickets thus removing the fraud.

Ticket gates read the coding, reach a decision re validity, determine updated coding, write the new coding and the verify - all within a few milliseconds. The same happens to Oyster Cards but far more checking is done with the latter because they hold far more data. Obviously with Oyster a decision was taken to ensure that agents could update cards with tickets / PAYG value and a new smaller unit was produced.