Fares Check - Choosing Approriate Routeing Point Group member

[JB_B]

When fare-checking a routeing-point group, the human-facing routeing guide(http://data.atoc.org/routeing-guide) is silent on how you choose a member of the group for the fares check.

The on-line routeing point calculator (http://data.atoc.org/rp_calc) seems to implement an (undocumented) rule that excludes routeing point members which can only be reached by passing through another member.

For example, when testing Brighton Group as routeing point for origin Shoreham-by-Sea, you compare Hove fares and not Brighton fares.

I'm not sure that this rule is well-defined in all cases (e.g for Lydney to Coleshill Parkway rp_calc rejects Birmingham Snow Hill as impossible to reach without passing through another group member even though that could easily be the first Birmingham Group member arrived at. ) It's also tricky to apply the rule without implicit knowledge of the local railway geography at a level of detail not given in the routeing guide itself.

I understand the electronic routeing guide simply defines a 'main' routeing point group member and all fare-checks on groups are done using that station.

Is there a publically avaiable list of these main stations for each routeing point group? (Some are easy to guess - others aren't.)

 

[yorkie]

...The on-line routeing point calculator (http://data.atoc.org/rp_calc) seems to implement an (undocumented) rule that excludes routeing point members which can only be reached by passing through another member...

I think someone who was given the job of creating the RP calculator just made it up.

...I understand the electronic routeing guide simply defines a 'main' routeing point group member and all fare-checks on groups are done using that station.

I have heard this mentioned before, do you have a source for this? (feel free to PM me if you can't disclose it)

The rules actually say that "the fares from all stations in the group must be found and the lowest fare price used for comparison", which makes sense, because to do anything else would undermine the principle of having a group in the first place.

Also, if the fares to a further station are cheaper, then it seems absurd to suggest that the entire group should fail the check on that basis.

 

[JB_B]

I think someone who was given the job of creating the RP calculator just made it up.

Could be... The capcha is horrible and it does seem to go wrong sometimes but I like that fact that rp_calc shows it's workings so you can check - not just computer says "No/Yes".

I have heard this mentioned before, do you have a source for this? (feel free to PM me if you can't disclose it)

Think I got it from http://www.railforums.co.uk/showpost.php?p=1192130

"No mention is made in the Routeing Guide that any station is considered a 'lead station' used for the purpose of determining appropriate RPs in the case of Group Stations, however the booking engines do have such a station defined for each group, which is used for the comparison."

Also, the RG data feed spec says it records a main station (also described as 'preferred' station for each group although the spec doesn't say what it's used for.

The rules actually say that "the fares from all stations in the group must be found and the lowest fare price used for comparison", which makes sense, because to do anything else would undermine the principle of having a group in the first place....

Thanks - not sure how I missed that - so effectively if the fares check is passed at any group member then the group is a valid RP - that's easier to implement.

 

[kieron]

The on-line routeing point calculator (http://data.atoc.org/rp_calc) seems to implement an (undocumented) rule that excludes routeing point members which can only be reached by passing through another member.

This isn't something journey planners do (or, at least, isn't followed by the one at nationalrail.co.uk).

For instance, an Upton-Combe ticket has valid routeing points in Shotton or Liverpool at one end, and Worcester or Oxford at the other (Oxford due to easement 30044). It doesn't pass the fare check for Birkenhead Hamilton Square, however.

rp_calc says there are only mapped routes via Shotton and Worcester Shrub Hill, but NRE gives various routes via Liverpool (and via Oxford) anyway.