Realised this morning that the MTB had a puncture and I couldn't be bothered to fix it. Got offered the car, but I really wanted to ride in the snow, and figured the skinny tyres on the fixed would cut through it. That was certainly right on the virgin stuff on the Innocent Railway. Avoid the footprints and the (very few) other tyre tracks and it was easy to keep on the straight and narrow.
There was definitely ice underneath, but the amount of snow deadened it. The biggest problem was car tyre tracks which not only compressed the bottom into a more slippy surface, but also created walls that were a little harder than the untouched snow, ready to throw a whell off line. Oh, and the fact that traffic was so heavy, but because on the main routes there were just two bands of black stuff showing it was pretty much impossible to indulge in the usual filtering (some imaginative on-the-fly route planning took me away from most of the traffic.
The worst, actually, was a taxi driver sitting a foot from my back wheel as I headed downhill, then overtaking me, throwing up snow everywhere. Only to pull in to a taxi rank 200 yards or so further on. I really should have stopped to remonstrate but didn't want to ruin the good mood.