Get a plastic card, if your transport authority still provides them. Not everything belongs on the phone.
For my locality, there's plastic RFID cards or app generated QR codes (with timestamp – you definitely need the app).
Pulling out my phone, unlocking, bipping, bopping, swiping and swooping to get to the darn QR code every time there's a ticket inspection soon got old. Hated it.
Going back to plastic card eliminated a lot of stress...