The Park And Ride spots around Norwich ('Konect' buses) charge £1-80 per person for concessionary fare (old gimmers' bus passes) That's £3-60 for two. It's never free.
If one drives right into Norwich and parks for a couple of hours in the centre of town multi-storeys, it's about the same cost. And one avoids waiting in the cold and the rain for a bus (no shelters!)
We do use the P&R in the summer, but we resent having to pay. It ought to be free with the Bus Pass.