Failed Unit
Established Member
That is where the difficulty would be as who would set the fares? If you fly to the US with Virgin Atlatnic you can't expect to return with BA on the same ticket can you? One option here would be to scrap return fares so you would buy a single before you travel on each train. In the future smartcard technology may help here as you could be billed for actual journeys on each train.
It sort of exists now as I can use my saver via east coast or west coast but rail is still walk on, if I am restricted to the 1700 only because that is the operator I have bought my ticket from that is a big backwards step, I may as well fly. I would be annoyed to wait two hours. Years ago you could turn up to BA with a British midland ticket, Ba would claim back the cash and carry you.