I think you've got your logic in a twist. It's the frequent users who are subsidising the infrequent. You have to think of it in terms of revenue, not people or journeys.
Your 10 people making 10 journeys may do that once or twice a week, generating say £1,000 in revenue at a fiver a go. The one person does that every week. So if 10 people make 10 journeys a week that's £5,000 in revenue, less their travelcard discount.
As I said, who's subsidising who?
I am proposing scrapping travel cards all together and making the price of each journey independently priced (therefore your example is of no relevance). I am simply asking why when a person makes more than one journey each journey becomes cheaper even though the quantity of service that the person recieves is equal to that which multiple people would collectively recieve.
I can understand why products where some costs are independant of order size (e.g. packaging/delivery) that greater batches should be cheaper because it costs the supplier less to produce.
One example of my suggestion would be cutting the price of singles to the price that one would effectively pay if they were using a travelcard. As a result those who presently do not use public transport in London much would start to use it more.
I think that we should take advantage of 21st century technology such as Oyster cards that were not available when travelcards were introduced. When travelcards were introduced they made perfect sense because they allowed someone to travel frequently with having to buy a new ticket each time (saving time and effort [and therefore money] for both the customer and the operator). However, now that Oyster cards have arrived and we also have a ability to pay for things online in the comfort of our homes (in one big go as PAYG), travelcards are no longer the only solution to that problem. Direct debit could even be used (with an extra discount).
Tickets prices at different routes/times could vary more than they do at the momment to encourage people to make more efficient use of services (making sure some are not too full and that others are not empty). A person could quickly use their computer/smart phone to compare different journey possibilities just before they travel (or well in advance) so that they know what fare they will pay.
If someone has their Oyster card stollen from them they could have a note of its designation to report to TfL and the thief could then be caught on CCTV using it to pass though the barriers (it would be easy to track since the location of each Oyster card is already used in order to calculate the fare).
To summarise I simply think that we need to take advantage of the new technology available to create a better system and to not keep one that is still subject to the limitations of the past.
