Pay with card, your bank charges you a fee for each transaction - could be several each day.
Pay with tag you only get charged once a month when you pay the bill.
No charges on my Halifax Card Also get the going exchange rate so cheaper than changing cash.
Or £26 up from (£6 fee, plus £20 Deposit) then another £5 fee the first time I use it, so £31 for the privilege of using the card on my first and last day of our annual pilgrimage, I can see it being good for anyone who uses these roads a lot, but we typically only have a couple of days a year when we have to pay at 2-4 booths.