Absolutely disgraceful deposit of mud by tractor drivers hauling harvested beets on Fen Lane (the back way to the north of Swaffham Bulbeck which many of us use to bypass the unpleasant B1102 through the village).  In my opinion it is not currently safely passable on a bike.  I was on foot, in wellingtons, and found it hard to stay upright.  The number of tractors and the aggressive speed at which they are being driven is an additional hazard.  Until this is cleared up, the options are the main road through the village, or (somewhat longer but much less busy), divert via High Street, Quarry Lane and Heath Road back on to the B1102 and the Greenway to Swaffham Prior north of the village.