For those who live or travel in Asia (Japan, Hong Kong, Singapore) most rail systems use NFC (specifically the Felica spec, NFC-F) to do touch payments. For example the Octopus card in HKG and Suica/Passmo/etc in Japan require this. It is also part of the global ISO / NFC Forum standard along with NFC-A-B.
If it's fully supported, you can add a Felica based rail payment card to your Google Pay app and simply touch your phone to enter the station gates or make other touch payments like at convenience stores or vending machines.
So, does anyone know if this will be supported?