There's a noticeable delay between contactless cards and oysters. Some people I know prefer oyster cards simply because they open the gates faster, in spite of having to top them off all the time.
I'm looking forward to not having to choose one trade-off over the other.
The MIFARE protocol (which Oyster cards use) takes 300ms to 500ms per tap. EMV (i.e. contactless cards) take ~500ms, which slows down normal walking speed.
It’s noticeable if you’re used to the instant response of Oyster, but we’re talking about a few hundred extra milliseconds. Not something that bothers you once you’re accustomed to it.
It’s still fast enough that it will read my Apple Watch before the gate starts to close from the passenger in front of me.
One saved trip to an Oyster top-up machine will make up for a lifetime of contactless NFC latency!
>but we’re talking about a few hundred extra milliseconds. Not something that bothers you once you’re accustomed to it.
Wrong. With the traffic volumes normally seen in Tokyo, those few hundred extra milliseconds will cause huge delays at the fare gates. There's a reason the systems here use the Felica card which processes in 100ms: it's really needed for this kind of pedestrian volume.
At peak hours it can definitely be a problem, you really need the entire pipeline to work well. There's going to be somebody behind you most of the time, and you really don't want people stuck at the gates.
In Japan credit card transactions routinely take a couple seconds. Imagine each person taking 5 seconds to go through the gate! I think what trials for credit card payments in transportation services there are doing is simply not processing the transaction inline, and just doing it after the fact (assuming it will go through).
Yes, the TfL system does a partial authorisation. It checks the card is valid and not blocked etc but doesn’t necessarily do a real-time authorisation all the way to the issuing bank.
If you try to use a card that is valid but has no available balance/credit, it might work for the first ride but then be blocked when you try to use it for the return trip.
Fares are batched throughout the day and you are charged once, overnight, for all rides that day (after applying any multi-ride discounts, etc).
This is different from some other cities where I’ve used contactless payments and they’d charge you immediately for each ride, giving you lots of annoying little charges on your bank statement!
Wonder how they block the card, my impression was that tokenization was meant to make it harder for card chargers to be able to track a card through multiple taps like that.
TfL not only gets your Apple Pay device account number (DAN), but can also associate it with the primary card number (PAN). Both magically appear if you add the primary card to your online TfL account and have used the associated Apple Pay device with TfL before.
> ”Is it not possible to top up a digital Oyster card on an iPhone or Apple Watch via an app or Apple Wallet?”
It is, there’s even an auto top-up option that adds credit automatically if your balance drops below a certain level.
But there’s no “digital” Oyster card, only physical ones. If you want to use a device to pay you have to use contactless.
And either way, it’s still kind of a pain to have to maintain a balance - especially if you’re a tourist or visitor and don’t know exactly how much credit you’re going to need.
I agree that being able to load a transit card into Apple Pay etc is also a good solution. The convenience of not having a physical card that can be easily lost or forgotten is probably the biggest benefit for me.
I'm looking forward to not having to choose one trade-off over the other.