Enquiry/Booking Site Discrepancies

[supervalkoinen]

I have been looking at time and fare results for a straightforward journey with one change between a Merseyrail station and a station outside Merseyside.
I don't wish to name the stations as they have a fare visible on BRfares, with route '.', which could be considered 'loophole'.

Using the same input data:
3 different TOC sites (GWR, Northern, TFW) fail to produce a single valid journey.
National Rail produces all the logical journeys but does not offer the lower fare, instead offering a higher fare.
The forum booking site produces the same journey times as National Rail but offers the appropriate valid lower fare.

Without my adding specific details, can anyone explain these discrepancies?

 

[Haywain]

Without knowing the details it sounds like the ticket is not valid on the routes you are seeing. Route '.' effectively means any permitted route, although it should only really be used when there is only one possible route.

 

[Watershed]

The rules that journey planners use to apply the Routeing Guide are ambiguously written in several respects, and therefore different journey planners will sometimes come to different conclusions as to the validity of a particular route (or fare on a particular journey).

It may also be that there is an easement in play, for which the supporting data might be applied in different ways by different journey planners.

That said, without the details of the stations involved it's going to be hard for us to really give much more than a general answer!