The rail industry appears to have no such safeguards in place; this is just the latest issue out of many that have been brought to light on this forum.
I wonder why they aren't interested. Still at least all the services are showing on National Rail Enquiries now.
They understand policy documents, not changes like this which are (in their view) “technical”, even though their effects are not remotely technical.
I tried Princes Risborough to Hanborough via London. I also tried London-Hanborough, but I don't know how useful that was as it's only 3 miles further than the route via Slough. On reflection, Heyford would have been a better option.
The way Chiltern wrote the easement (Princes Risborough ... London ... Oxford) suggests that they were worried about people visiting those stations in that order. They were probably trying to prevent something more specific than this, but that's all I can glean from what they've said in public.
I guess that then comes down to - when you have a station group as a destination, what determines the stations you can choose from, for the purposes of the shortest route rule?
The shortest distance is calculated using the distances between stations in the routeing guide data - this is between stations (all of them), not groups. I would say that when checking a journey to, say, Old Street, it is the shortest distance to Old Street that is relevant. There's nothing in the instructions to say that other members of the same group should be brought into the calculation as well to see if they're closer. Can you think of an example that seems to be based upon the group?
For completeness, an Oxford to London Terminals ticket is valid into Paddington (using map LH or the shortest route rule), Marylebone (using map GC), or any of Waterloo, Victoria or Charing Cross (using map RB+WX).
I'm unsure what doubling back you had in mind? The only double back would be between junctions, not stations, so they obviously don't 'count'.
I’ve seen a mention of conflicting easements but haven’t been furnished with details (and have no inclination to look further).
Thank you! The plot thickens.
I would already expect a reworded/recoded easement to arrive at some point...That’s quite possibly the ticket mentioned upthread that the poster didn’t want to reveal…
Surely the map combination(s) for the route could just be amended? (I haven't looked myself, so I don't know how easy this would be)
The only map showing for Aylesbury to London Group in the Routeing Guide is CI, which is Aylesbury to Marylebone via either Amersham or High Wycombe. How Trainline is managing to route such a journey via Oxford when it's neither a direct train, nor the shortest route, nor a mapped route is beyond me!
I think that's the original problem. There's an error in the distance tables, or something, that is causing the routing engines to allow that route. But rather than trying to fix that error, someone initiated "easement" 700948 which had the side effect of disallowing Chiltern's Oxford to Marylebone service.
I suspect that the mileage link that connected the Chiltern lines to the GWR lines (around Greenford / Action? I can't remember) has disappeared, because there is no longer one service from Padd to the Chiltern route.
Although the line from Greenford to Old Oak Common has been severed, there's still the one per day service from South/West Ruislip to West Ealing. That would give a route from Aylesbury to Paddington via Princes Risborough. That's retained for route familiarity purposes as a Chiltern diversion if Marylebone is closed.
Is that a public service or an ECS move? I can't find it in the NR journey planner.
...particularly given the number of errors are found in these sources.