Piratemonkey made the below suggestions as a comment but I thought it warranted wider consideration:
Solving the teenager and pensioner problem is simple. Once the system has been in place for 6 months cash fares become 5 bucks no matter what, with no pensioner or student discounts availible. Then no one can mess with coins and there is a good incentive to look into the card.
To get a student or pensioner discount people will need to use the swipe card. Pensioners should be issued the card free if they ask for it and teenagers can simply learn. It will not take long once the system is in. During the implemetation everyone with who asks for a pensioner/student fare can be issued with a flyer explaning what is coming.
I just hope the stupid ACT government would extend the card to being able to also pay for parking at the outer town centres when being used in a “Park and ride” type scenario.
Hell put the system in taxis as well and it can be the comlete flexible canberra travel solution. Therefore saving my precious change for important things like coffee and fundraiser chocolates. Oh and if action is listening i will pay a $20 premium if i can pick the design on my card.
Any other ideas?