MBTA's Fare Transformation program is phasing out the old CharlieTicket with "Tappable CharlieTicket". Under the hood, their storage is changed from magstripe to RFID.
CharlieTicket is still an important tool to get MBTA passes that work on every mode before the Fare Transformation is fully complete. I have found lack of information on this technical change, so maybe it's time to document some of them.
Why the change
My personal guess is that they can phase out magstripe readers. This is actually a trend everywhere else — magstripe ticket readers usually involve mechanics to move the ticket and thus it's more prone to malfunction.
On some newer MBTA gates, they have only a RFID reader and an optical reader. The optical reader seems to be reserved for Commuter Rail use cases with the barcode of mTicket, Amtrak ticket, or DoD CAC (this one is interesting). I have seen people attempting to use mTicket to enter subway stations which I find very confusing — they are not even at a station with commuter rail access, so I don't know how they get to get a mTicket with that.
I did notice that the various tap target has been a bit confusing for tappable CharlieTicket customers. I have seen people tapping it on the old rectangular readers with the subway and it just doesn't respond. The MBTA announcement says the new tappable CharlieTicket does work with onboard fareboxes on the Green Line or buses, even though they have a rectangular tap target similar to those unsupported counterparts with the subway gates. I will need to try it out sometime.
How to get Tappable CharlieTicket
The subway vending machines now by default vends CharlieCards. The only cases when the machine will vend printed CharlieTicket would be when:
- Buying a single or double trip ticket;
- Buying a daily, weekly, or monthly pass, and you explicitly select Commuter Rail or Boat. Commuter Rail 1A zone pass is essentially just a LinkPass, but if you select the LinkPass option, the machine will give you a CharlieCard instead.
They are all under the "buy a CharlieCard" menu, and you can't tell whether you will get a CharlieCard or CharlieTicket until after you pay for it (and I don't know if this is worth a visit to the Charliecard Store). There's no refund if you get the type of ticket that you don't expect, so be careful about that.
What's the Tappable CharlieTicket under the hood?
According to multiple NFC apps on my phone, it's a Mifare Ultralight EV1 chip.
It's actually not too bad to be used as a regular RFID card. I can still leave it inside my wallet to scan like a CharlieCard. The read distance doesn't reduce too much just because it's paper-based and cheaper.
The save-a-buck happens with the paper carrier, which you probably don't want to use beyond a month because it's pretty prone to damages. It also has a way smaller memory and weaker security protection than a regular Mifare card.
It's definitely more expensive than the magstripe though, but not too bad compared to a full card. According to my quick lookup online, it's ~$0.1 for just the chip itself. The full Mifare card is usually ~$0.5, and the full magstripe paper is usually ~$0.2.
If you would like to learn more, I highly recommend reading Mifare datasheets.