On Jun 18, 7:08*pm, MatthewD wrote:

FGW is perhaps the most interesting example of this happening, as they're
the least enmeshed with the Underground network of all the
north-of-the-river TOCs yet they accept Oyster PAYG on their routes
throughout the London zones. Sure, c2c and Chiltern accept it throughout the
zones as well these days - but their routes are very much entangled with the
Underground network.

By the by, the map of current Oyster PAYG acceptance on NR can be found here
(PDF):
http://www.tfl.gov.uk/assets/downloa...ional-rail.pdf

While there isn't any FGW interavailability, the common gatelines at
Paddington, Ealing Broadway & Greenford would make it tricky to change
from the LUL PAYG rates.

True - at least for journeys between those three stations. But FGW
could decide to charge the higher NR PAYG farescale for other journeys
- or if that led to too many anomalies (e.g. Acton Main Line to
Paddington being more expensive than Ealing B'way to Paddington) then
perhaps for journeys beyond West Ealing on the GWML they could adopt
the higher NR PAYG farescale.