It is a tricky thing to decide the fine line between:
- Travelling beyond validity (resulting in a PF)
- Travelling off route (no PF).
I think a lot of common sense has to be applied to such situations to determine if the place being off route offers better services to the destination and if the customer has a genuine reason for being there. Take the following example.
I once travelled from Leicester to Coventry via Birmingham New Street. The route was valid at the time 18 months ago but isn't any more and the connection must now be made at Nuneaton. I'd like to think if I was on this ticket at BHM again I'd be deemed 'off route' rather than 'beyond validity' as the reason for me being in BHM on this journey isn't completely barmy and BHM has more services to Coventry than Nuneaton and offers more station facilities. Indeed at certain times of the day it is quicker to complete the journey via BHM too. There are 5 trains every hour to Coventry from BHM but only 1 from Nuneaton.
If say however I ended up in Derby to get to Coventry then that would be rather suspicious as I'd have no reason to be in Derby on this ticket. Even though there are direct services from there they all go to BHM before Coventry and provide me with no better service than is at Nuneaton.
Also, there is only a 5 minute connection available at Nuneaton and for those unfamiliar with the station it may not be enough, especially when the arriving service from Leicester is late. It would not be completely unreasonable to stay on the train to BHM to get a connection there rather than wait at Nuneaton - in the elements - for almost an hour.
I think in such situations if it is evident the person is going to a station not valid by their ticket to take advantage of a better service it should be deemed 'off route'. If it is clear they are taking the mick and can't explain why they are there then it should be 'beyond validity'.
I think the fact that both of these reasons exist is clear that routeings are totally bewildering from a passengers perspective. As Tom C said it is looking after the passengers interests - after all, how many people do you know who routinely check the routeing guide before they travel? When in the situation you make split second decisions about the route you are going to use to the destination. You can't check if it's valid when you're on the train at Nuneaton with its doors closing so the system needs such safeguards. ATOC are probably aware the routeing guide is very shoddy in its current state but they don't/won't/can't (you choose) do anything about it.
The next question is if I am deemed to be off-route in the above example what would I be given ticketwise? I'd assume if I had a return, it'd be a return from Nuneaton to BHM and a return BHM to Coventry. Problem is as Tom C describes in another thread* (the one that describes the off-route/beyond validity problem), normally tickets are excessed from a 'Not xxx' route to 'Any Permitted' to enable the route to be valid. This can't happen here as there isn't a 'Not Birmingham' route as well as the 'Any Permitted' (which if the former existed this would be valid via BHM).
At the end of the day, I think the distinguishing between the two scenarios takes common sense to see what the passenger is trying to do and make the appropriate decision based on that.
*
http://www.railforums.co.uk/showthread.php?p=222930