Yesterday night we got more snow. Snow on snow on snow. This morning I took my usual back roads route to work, knowing there was a good chance of at least some snow remaining on the lesser-traveled roads.

Mostly it was OK; I averaged about 11 or 12 miles an hour, perhaps. The killer roads come with 3 miles of work: Tiny neighborhood roads that I swear never see a plow, are heavily shaded by dense trees, and to whom the touch of salt or sand are complete anathemas. They had a inch-thick covering of packed-down snow, which the Ice Bike website describes thus:
Heavy snow that has been traveled upon by automobiles is one of the most difficult of surfaces ICEBIKERS have to deal with.

Not only do you have the wheel diversions caused by the ruts, but also the polished smooth surface underneath where cars have spun tires trying to get going.

The best technique is to avoid this stuff, riding in the undisturbed snow at the side of the road. While a lot of work, undisturbed snow is always easier to deal with than trafficked snow.

If your balance good you can sometimes make progress following the tire track, but don't count on it for very long, and certainly don't expect to make good time. Also, there is a thin layer of highly compacted snow at the bottom of the track, that tends to squirt out from under your tire throwing you slightly left or right.
Getting through heavily trafficked snow is seldom elegant, often a lot of work, and always a nerve wracking experience, especially if there is automobile traffic nearby.

Frequently, the falls that seem inevitable from second to second can be avoided by continuing to apply power and steering as best you can. Your side slipping front wheel often bites when it hits a slightly more solid ridge, and if you can delay the fall for half a second or so you may find that you can recover. Don't be in a hurry to dab, stay on the pedals and apply power. This is a lot like riding in loose sand.

As you power through this stuff, you will have to make rather large steering corrections to compensate for impending falls. This preserves your balance. You will, however, find yourself going in a direction slightly (or not so slightly) different than you intended, and this can not always be permitted if motor traffic is in the adjacent lane.
This pretty accurately describes the conditions I rode in. I actually got off and jogged with my bike for a while and made faster progress than I did on two wheels. That warmed my feet up, at least. Part of the way while I was on my bike, as my wheels went sliding in separate directions, I suddenly realized that this was more like sledding or skiing than biking.

Total distance this morning: 13 miles
Total time this morning: 1 hour, 20 minutes

Typical for a snowy day. I'm getting really, really tired of snow.

On the bright side, somewhere on those snowy back roads I passed 10,000 miles ridden since September 2007, so all was not in vain.