In message
, at
03:17:45 on Tue, 26 Jan 2010, DRH remarked:
But how many journeys combine two short single journeys with an
interchange outside the gateline? I imagine these are far from the
norm.

Now that there's Oyster acceptance on National Rail, most journeys
through a terminus. If you want equality of fares from (eg Finsbury Park
to Gt Portland St, irrespective of whether you use tube or NR for
Finsbury Park to Kings Cross, you have to allow an outboundary change.

However, what was probably the most common outboundary change within the
tube system is now in-boundary (deep level to subsurface at KX).
--
Roland Perry