On Mon, 07 Jan 2008 01:02:27 +0000, JNugent
wrote:

Is the amount worked out on the basis of an estimate of how many times
a day/week/month a typical concessionary-pass-holder might use the bus?

When they flash their pass the driver clicks a counter. Or there's
some card-reader system. At least that's what happens on every 'bus
I've ever noticed. So the actual number of journeys could be claimed.