On Thursday 29 August the zonal pay-as-you-go (PAYG) fares system for London was extended to cover Brookmans Park station in Hertfordshire. This is particularly notable because Brookmans Park is the first (and so far, only) station within the system at which Oyster cards are not valid.
I’ve taken the opportunity to make some changes to www.ltfares.com in order to make it clear which prices are available using both Oyster and Contactless Payment cards, which prices are Oyster only and which are Contactless only. For example:
Oyster, CPC & Cash 
Oyster only 
CPC only
(I also took the opportunity to add in an icon of a little pile of pound coins to cover the case where a cash fare is shown!)
With this development, it seems to me now more obvious than ever that the London PAYG system really consists of two separate but similar systems, with subtle differences between them:
Oyster Card
Oyster Cards are loaded with credit, which is deducted on a pay-as-you-go basis as you make each journey. The prices for each possible journey are shown on www.ltfares.com. Oyster Cards apply a daily cap, based on the times you travel and the zones you travel through, and won’t deduct any further credit on a given day once the cap has been reached for the zones you have travelled in.
The way the cap is calculated is sub-optimal because it uses a relatively simple algorithm and credit cannot be re-added to the card after it has been deducted (the charge is always calculated in real time and deducted from your card there and then when you touch out; in fact most London Underground ticket gates will flash up the price they have just charged you).
Similar limitations mean that a weekly cap cannot be applied to Oyster Cards: despite having been promised for years, it has never been implemented, presumably because it is technically impossible to calculate it in a fair manner.
However, if you know in advance you are going to be travelling regularly, you can add a weekly, monthly or longer period Travelcard to your Oyster Card. This will give you unlimited travel within the zones you have paid for, with the added bonus that, as long as you have touched in at the start of your journey, you can travel outside the zones covered and will be automatically charged the correct extension fare when you touch out.
The biggest advantage of an Oyster Card for the average passenger is the ability to add a railcard to it, which then gives you a 34% discount on off-peak fares and on the off-peak daily cap. The railcards which can be added in this way are the 16-25, 26-30, Senior, Forces or Disabled (the latter additionally giving the discount on peak fares). The off-peak discount is also available for holders of Annual Gold Card season tickets, and it can be added in the same way (e.g. by asking a member of staff in the ticket hall of a London Underground station).
Contactless Payment Card
Contactless Payment Cards are tapped in and out in the same way as an Oyster Card, but the big difference is that the price they charge is not calculated or deducted in real time. Rather, what is known as a “back office process” calculates the optimal price for all the journeys you have made each day, and charges your card once at the end of each day.
Because the calculation does not need to be done at the time you touch out, it can use a more complex algorithm than Oyster does, looking in retrospect at all the journeys you made that day, and trying various combinations of zonal caps and extension fares to find the best price.
The prices for individual journeys are shown on www.ltfares.com, as with Oyster. The big drawback with Contactless compared to Oyster is that you will always be charged the full public (adult) price; there are no railcard discounts available.
On the other hand a big advantage of Contactless is that in addition to calculating the optimal daily price, it will also calculate the optimal weekly price for each Monday to Sunday period in which you use the same Contactless card for travel. If you don’t have a railcard, and aren’t certain whether you’re going to be travelling enough in a given week to warrant buying a Travelcard in advance, this can be really advantageous.
However if you’re going to be travelling a lot over a 7-day period that spans the transition between two Monday-Sunday capping periods, you’d likely be better off buying a Travelcard to cover that specific 7-day period. And if you load it onto an Oyster Card with the railcard discount enabled, you can also take advantage of the railcard-discounted extension fare when you make an off-peak journey outside the zones covered by the Travelcard.
Brookmans Park – Oysterless!
There are certainly quite a few niche and edge cases where it’s not at all straightforward to determine whether Oyster or Contactless is the best option. However if travelling to or from Brookmans Park it’s much simpler: Oyster is simply not accepted there; if you want to use PAYG, you must use a Contactless Card. Of course this means that you can’t have a railcard discount, since railcards can not be associated with Contactless Cards, and the range of fares offered on PAYG is narrow (only Peak and Off-Peak) so it may be more cost-effective to buy a conventional paper ticket, e.g. when travelling at weekends when Super Off-Peak fares are available.
The reason for the Contactless-only PAYG fares is simply that, as noted above, the Contactless price calculation is much more flexible and can be much more complex than Oyster, taking into account many more fare zones than the Oyster system is capable of, and covering stations further away from London. I believe it is very likely to be a model for further extensions of the PAYG system, perhaps to Reading when Crossrail/TfL Rail services start operating later this year.
In Summary…
I hope this makes the Oyster/Contactless distinction much clearer for all users of the site! Let us know in the comments below if you have any suggestions for any further improvements.
I would also like to think Mike Whitaker from the www.oyster-rail.org.uk site, who reminded me of the need to make these updates!
