In message , at 14:13:12 on Tue, 28 Feb
2012, Adam H. Kerman remarked:
http://en.wikipedia.org/wiki/Avantix_Mobile

Right. I didn't think those were wireless devices.

That's probably right. I thought perhaps they had a version with GSM/3G
data built in, but perhaps not. As a result, the range of credit/debit
cards they can accept is restricted.

However, if the transaction appears suspicious then the ticket seller
can opt to make a mobile phone call to obtain authorisation.

I wasn't thinking about ticket-printing machines, per se, but getting
back to another discussion we had in which the credit card number itself is
used as the ticket medium and the passenger gets billed for all passage
at the end of the month.

I've never encountered such a scheme.

There's a proposal to do *daily* billing via paywave credit cards for
travel in London, but I don't know how they propose to "inspect" the
ticket, because you can't 'load' one onto a credit card. I suppose
they'd need to use your credit card number to make an enquiry from their
own merchant account, to confirm you'd "touched in" recently.
--
Roland Perry