I don't know about the rest of the UK, but in South Yorkshire the Pensioner fare used to be the same as a child fare - which was about 30p in 2008 - but has risen to 80p (i.e the child fare has gone up in line with roughly the cost of a third of a typical adult fare).
I'd be interested to see what revenues 80p per pensioner would bring in in 2019.
It's an incredibly expensive way of keeping elderly people active (and also you've got to wonder how active they are when sat on a bus).
I'd be a lot more in favour of the "carrot" of free bus tickets if it came with the "stick" of regular driving tests when people reach age sixty - given the damage that just one crash can cause. There were some scary sounding figures doing the rounds after the Prince Phillip smash last month re how many elderly people refuse to give up their cars.
(that said, I'm all for regular re-tests of all motorists - the requirements have changed a lot since people sat tests in the 1970s/1980s/1990s - people have forgotten a lot since they were seventeen - people have picked up a lot of bad habits over the decades - but I appreciate that this is a whole other discussion!
Part of the problem is that, now people have had over a decade of free travel, it'll be very hard to get them to accept paying *anything* - pensioners under seventy five might not have had any experience of paying for a OAP bus ticket - once people are used to freebies, the value that they put on the product is devalued.
For example, I read the Metro on a bus.train, it's an okay newspaper - I benefit from reading it - but if the bus/train company started charging a token amount (say half of the cost of a regular tabloid, maybe thirty pence?) then I'd resent that because I've never paid for a Metro and therefore don't place much "value" on the newspaper (despite all of the copies that I've read).
Same goes for car parking - now that people are used to parking for free at Retail Parks/ Out Of Town Malls, the idea of paying a whopping fifty pence to park in a city centre is enough to bring people out in a rash - once you give people something for nothing it becomes very hard to get them to pay money for it.
I think that, unfortunately, we've created a situation that will be very difficult to get out of - pensioners expect their freebies - pensioners are so used to the freebies that they don't consider a journey to be worth a quid - pensioners won't pay a quid - but bus companies get paid so little in reimbursement that even a bus full of pensioners isn't that lucrative for them - I don't think there's an easy answer (without seriously annoying a very vocal demographic who vote in large numbers and have high expectations of the kind of things they expect for nowt).