In message , at 15:48:39
on Mon, 8 Feb 2016, David Cantrell remarked:

Well unless the RID has a realtime radio link to the main computer I don't
see how else it could be done other than by a reconciliation later.

Mobile data hardware and airtime is dirt cheap these days, so I'd not be
at all surprised to learn that ticket inspectors' hand-held devices can
talk to head office in real time.

The problem with that is the lack of coverage, especially in the hostile
tube/sub-surface environment. If you want to be able to do checks in
real time you have to be able to know who touched in (or didn't) at the
station you just left a minute ago.

I was thinking you might manage it, just, if every station had reliable
wifi you can snatch 20 seconds at a time, but even then there will be
times that the data hasn't caught up with the inspectors.
--
Roland Perry