Just popping back to 2009 for a second, one of the original posters then, mentioned a 12km long lane paralleling the A604.
This is Roman Road and has been TRO'd for almost as long as I can remember. Most lanes in South Cambs are Seasonal TRO, open possibly between May & Sept as long as it doesn't rain!
Regarding Peddars, there is talk of shutting the Anmer bit again due to the 'repairs' cutting up again. Not repaired to sufficient standard comes to mind!
There is a stretch of Peddars south of Fring and adjacent to Red Barn Farm that has never had MPV rights despite motors continuing to use it. Similarly from the ford at Fring up over the hill is a no-no too, although years ago we actually watched some lads in a Ford Explorer drive up the hill and over the top - ploughed as well! Didn't get the VRM or would have gladly passed it to the authorities.
Whatever you do, get the latest info that you can from club ROW guys and/or Council dept