Apple Pay offers a little known feature called 'Express Transit', allowing you to use Apple Pay at transport readers without needing to authenticate, and iOS 12.3 adds support for using payment cards.
Apple is set to enhance transit support in iOS 12.3, allowing an existing EMV (Amex, Visa or Mastercard) card to be used for 'Express Transit'
TriMet is the first transit provider to support Apple Wallet in North America with the 'Hop Fastpass', supporting concession fares, and longer term passes which aren't available with payment cards in Apple Pay.
Samsung Pay adds transit support, allowing you to use a default transit card to travel in Sydney quickly and easily (without having to authenticate for every trip)