In message , at
19:32:32 on Wed, 17 Sep 2014, Arthur Figgis
remarked:
If I can by a coffee at Starbucks by waving a CPC, and it ends up on my
bill at the end of the month, it does seem as if waving a CPC at a gate
ought to register my presence with enough information to bill me
overnight once I've also registered a touch-out. But clearly it's all a
lot more complicated than that, given the kerfuffle to get it all in place.

Because Starbucks knows how much to charge you before you wave your
card, but TfL doesn't know whether you will make more journeys today.

You've missed the point. The TfL gates "know" to charge you £0, and send
that message along with your location back to HQ. At the end of the day
someone looks at all the £0 charges and works out where you've been and
what non-zero charge to apply to the cardholder.

Readers in shops can occasionally ask you for a PIN, but ticket gates
can't do that. This means new rules were needed,

That's a completely different bit of governance work which the card
companies claim was done years ago (at least two years for acceptance on
buses, obviously).

as well as new software.

Not really, the terminals just have to desist from asking for a PIN if
they don't have a keyboard. That was sorted for acceptance on buses in
2012.
--
Roland Perry