Broadly speaking, there are two ways in use for dealing with the accounting
issues. *One is to count every use (eg by pressing a button or issuing a
zero-priced ticket) and the other is to sample the traffic from time to
time and extrapolate.

This is my point. It seems to take a knowledgeable driver a fraction
of a second to press a few buttons, in order enter a destination, fare
type, and issue a ticket, when a fare-paying passenger boards a bus.
Surely, for accounting purposes, it would be much more accurate for
the driver to do the same for LA passes, only issuing the ticket as
zero-fare. This way, the company will be able to bill the LA for the
journies actually made, rather than just number of journies made -
which could be the entire length of a route, or just one or two stops
down the road.

M