How to use Express Transit to quickly pay for rides via Apple Pay on iPhone and Apple Watch

Thanks to the Express Transit feature that's available through Apple Pay, you can hop on the tube, buses, trams, light rail and overground rail in major cities and pay for your public transit journeys just by holding your iPhone or Apple Watch close to the contactless NFC terminal, no need to press any buttons or verify with Face ID, Touch ID or a passcode whatsoever.