"JohnLon" wrote in message
...
I wonder how the ticket prices would be reckoned. Feltham and Heathrow
are in Zone 6, but Staines and Ashford (which the train passes through
are outside Zone 6.

No mystery, they'd be in either a special zone where National Rail fares
apply; as per Watford Jn, and 'zone G' on c2c routes outside zone 6; or if
the fares were usable zones 7,8 or 9.

If it ever happens the precedent will already be in use anyway, as the
greater Anglia franchise is extending PAYG outside the zones to Shenfield
and Hertford East next year some time...

Paul S