Yesterday while transferring between the Green and Blue line I encountered a group of officers enforcing fare payment armed with card readers for TAP. I used a day pass on that occasion so I didn’t get to see them in action. Plus, I was in a hurry. So, this is a heads up to everyone out there using the TAP card.
As a side note, it seems logical to allow TAP card owners to buy a day pass and load it onto the card. One of their selling points is the eco-friendly nature of the card. Perhaps that is a feature to be added in the future.