I’ve seen that system in quite a few cities now. I’m was initially surprised to see it adopted, because breakage revenue can be enormous. But it’s common enough now that I find places using exclusively the old stored value cards to be outright contemptible.

Think about it from their shoes. Why would you actively spend resources to replace an existing "working" system to develop and implement a new and more efficient system which nets you less resources?

One reason could be to enable novel fare systems, like London has with its Oyster network.

You can travel around (scanning your contactless debit / credit card) without thinking about how much you’re paying, safe in the knowledge that the system caps your daily / weekly spend to predefined limits, essentially making it never more expensive than a daily / weekly travel card would be. The caps are automatically calculated for the zones you travel in.

It’s a very nice experience as a rider. Especially beneficial to visitors who can just scan through the gates as any Londoner would, no ticket purchase required.

As for the rationale to implement such a system — well, it’s ultimately a public service. All revenue generated is reinvested into the network, in London at least. The economic value of a fast, efficient, painless transit system that everyone uses, regardless of class or wealth, most surely outweighs any lost breakage revenue.

NYC really needs to get the tap to pay working for AirTrain at JFK. I’m not even mad about the ridiculous $8 fare (though that’s another issue) it’s the having to stand in line to purchase a paper card that I won’t use again until I return to the airport to go home.

I believe that since February 1st (so 4 days ago) you can also use contactless debit and credit cards for train travel throughout the entirety of the Netherlands. I think that most if not all regional public transport providers, for say bus/tram/metro, already support it as well.

Can't use it when you have a subscription though, so a lot of people here will still be using their plastic public transport cards for personal and work travels, including me, but it's nice to have the possibility at least.

https://ovpay.nl/en

Still OV-chipkaart is useful as it allows you to take OV-fiets.

Contactless debit cards from a bunch of countries aren't accepted on london underground. That makes it less good for visitors. They don't even publish a list - just some will refuse to work, and you have no way to know as a visitor till you try it.

For even more confusion, some contactless debit cards won't work the first time, but if you try them 5 mins later (presumably after the main office has done a test charge on the card), it then works fine.