[Update 7:55am - Apparently you can enable Express Transit mode on a credit card but it still requires authentication at the moment. Will monitor and update accordingly.]
Just last month, I wrote about how you can use Apple Pay on public transport in Singapore - all you have to do is to link a Visa or Mastercard to your SimplyGo account and then use that card (physical or otherwise) on the trains and buses in Singapore. While I thought that Express Transit Mode was not enabled in Singapore previously, a friend of mine actually noticed that that you can in fact, set up a payment card in Express Transit Mode.
Now what exactly is Express Transit you say? Essentially enabling a payment card as your Express Transit card enables you to ride transit without authentication. This means that once you have correctly set-up this feature on your mobile device, you can essentially tap your iPhone without authentication (no need to complete Face ID, Touch ID or enter your passcode). Why would you want something like that? Well, for a start, it makes traveling a whole lot easier - you will no longer have to worry about holding up the line if your authentication fails (especially during peak hour!).
If you are using an eligible Apple device, you can set one payment card (e.g. credit card) and one transit card (e.g. Suica in Japan) per transit network. Since EZ-Link cards cannot be added as transit cards for now, your payment card should automatically be selected by the contactless reader. If in the future, EZ-Link cards can be added as a transit card however, the transit card always takes precedence over the payment card.
iOS users can enable Express Transit mode on their iPhones and their Apple Watches easily and here's how you do it according to Apple. Once you have your payment card (i.e. credit card) set up with Express Transit mode, you should be able to see the selected (credit) card via the aforementioned settings and this should work without the need for authentication. I have not personally tried to verify whether this works on the trains and buses but seeing as to how I can actually enable Express Transit mode on my OCBC VOYAGE Card, it seems unlikely that it would not work.