On 29 Jun 2006 09:33:49 -0700, Mizter T wrote:

I think the system has been thought through in a very detailed way, and
any assumptions it makes would be regarded as reasonable by most
people.

The potential complexity comes when Oyster Pre-Pay is implemented
London-wide on National Rail (NR). The possible issues here would be
similar to the above, where an A to B journey could go via C or D where
changing at D might be a slower but cheaper route than changing at C -
(similar to the 'route -not London' tickets that are already sold by
NR).

At first I thought so too; but the more I think about this, the less
convinced I am that it would really be a problem (at least, no more so
than it currently is with the Tube).

Most of the time, the choice is between a faster route via Z1 or a
slower route avoiding it; but with NR, you almost always have to pass
through a barrier when crossing Z1 (assuming they put some in at
Waterloo; then I think FCC would be the only exception). So the system
would be able to know whether you went via Z1 or not.

Can you think of a concrete example on NR where there would really be
a problem? (I'm struggling to think of one where the "cheaper" route
isn't ridiculously slow.)