I just came back from Madrid and while looking at my Madrid Metro card on the plane, thought imagine if you could use the same card in different locations? Its one of the reasons why I still use Uber, the ability to use it in different countries.
It was surprising to me that my Amsterdam OV-chipkaart which I bought back in 2006 was still active when I went back in 2016 actually; so I’ll be keeping my Metro card complete with its balance of about 4 rides. My Oyster card still worked when I moved away but as its 1st generation, isn’t manageable from the TFL website (I need to swap it out next time I’m in London).
Realistically it would be very difficult to get all these government entities to come to a common standard but its worth trying right? Although this might be all null, as its interesting to see the London Oyster slowly? being replaced by contactless debit/credit cards instead? That does seem to make much more sense and you can manage it from a web service and a app; yep another bloody proprietary app (I’ve already had enough of each service having its own app!)
It could be a great boom for public transport generally. Take the best of ride sharing services like Uber but for the public benefit. Think of it like the Japanese PASMO and SUCIA cards but based around standard NFC/contactless bank cards? Of course theres always the option of cash, phone and other NFC devices if you prefer.