Yeah, but most councils insist that you can't use P+R for that. You must get the bus. But the buses back from Norwich to its sites stop at 7 or 8. I could get back if I had a bike.
But you're not allowed folded bikes on most buses around here. So I'd have to get one out of the dock at the bus station and drive back in with it afterwards. To heck with that! Then the kicker is that they've just stopped running buses from the western P+R to the city! So I still drive into the city centre car parks
Rather sensibly, Cambridge now sells "Park Only" and "Ride Only" tickets at its P+R sites. Why don't all cities? That said, I'm usually visiting the centre or south of Cambridge, so the train works better than the A10 across the fens...