The Null Device

The British rail fare labyrinth

The BBC News Magazine has posted a very informative article on ways of legitimately gaming Britain's byzantine train fare system to get the best fare. Most of these ways involve finding the right combinations of tickets covering various parts of the journey which, when put together, are cheaper than a complete ticket would be:
These are not "fiddles" but perfectly legitimate savings, because it is the customer's right to ask for any combination of tickets. However, it is also the clerk's duty not to advertise them, should he or she know they exist.
The only rule connected with the use of such a combination (other than the fact the tickets must be valid, of course) is that the train must stop at the place where the tickets join, although you do not have to alight.
A few examples:
You have to leave London for Newcastle on the 0800 train and the open return costs £224. The train calls at Peterborough - and savers to the north from Peterborough are available any train, any day. So book an open return to Peterborough (£68) then a saver from Peterborough to Newcastle (£76.90) - that's £144.90, saving £79.10. Just make sure the train on which you return calls at Peterborough (most do).
And another one, exploiting the fact that return tickets to London from Wales can be cheaper than single tickets from Chester (near the Welsh border) to London:
So buy a saver return FROM London TO Shotton and throw away the outward half. You are then "returning", resuming your return journey at Chester. That is all legal. The saver return is £59.70, £29.30 less than the full single.
The reasons for this labyrinth of anomalies is a legacy of John Major's privatisation of British Rail, which left the pricing of different journeys along the network in the hands of different companies, thus ensuring that the exact start and endpoints of individual tickets have an arcane, almost alchemical significance.

I wonder how hard it would be to create a search engine for automatically finding optimal combinations of tickets.

There are 3 comments on "The British rail fare labyrinth":

Posted by: toby Thu Mar 15 06:35:19 2007

If you have all the information, pretty trivial to write a bounded search (you can prune any lines of search as soon as you go above the cost of the original ticket). The logic to allow you to use only part of a return ticket would be relatively tricky.

If you can gather all the information somehow, I think you should give it a go. It'd be an interesting exercise. It might also be an 'interesting' legal exercise (s/'interesting'/expensive&painful/)

Posted by: acb http://dev.null.org/acb/ Thu Mar 15 09:48:38 2007

The question is: (a) finding a representation of the British railway network as a graph of nodes, (b) accessing fare information as a web service (which would have to be done live, given that cheap tickets sell out first). (b) may annoy the operators of the ticket booking websites if there's too much of it; though if the site had some empirical information on which stations are the best midpoints for dividing tickets along, it could just try those.

Posted by: toby Fri Mar 16 00:34:14 2007

I think you'd be better off not doing it live. I appreciate that live is useful, but most of the utility would be in knowing the options that exist, ranked from cheapest to most expensive. If you have the ticketing information (including all the stops for each journey) then you implicitly have the connectivity graph of the rail network.