Parking lots and ice
The Wolfram Research parking lot was across State Street from our building. It was rather trecherous during the winter, when ice would build up very easily.

During one week it was really bad, and the ice was almost thick enough to have a hockey game on it. Although the building management was constantly spredding salt all over the place, it did very little to help. The combination of snow and the melting and refreezing didn't help the situation. It was so bad I took my mountain bike to work, in spite of the cold.

I got plenty of opportunity to learn all about driving on ice. More accuately, now *NOT* to drive on ice. What didn't help was that the parking lot was tilted at a slight angle, which made parking very interesting. When you attempted to slow down, you would hit black ice and start sliding sideways. One time, I came within two inches of another car. It seemed that no matter how slow you drove, going through the parking lot was a real test of your ability to deal with adverse conditions that were simply thrown at you.

My apartment complex was also bad, especially on the north side where I was. We didn't get a lot of direct sunlight, which helped clear up the west and east sides. Their lots were basically clear of ice. We still had lots of built up snow and ice which refused to go away.

The scariest experience I had driving was one early morning. I was driving slow while approaching Vine and East Michigan in Urbana, and I hit some black ice just before the stop sign. I spun 270 degrees and slid across the intersection. Fortunately, it was 7:30am and there was no traffic in either direction.

The problem I saw with the salt was that it tended to simply wash away, and you were constantly seeing trucks dumping salt on the roads. We use sand in California for three reasons:

1) When the ice melts and refreezes, the sand will still provide some traction
2) The environmentalists were complaining that the use of salt was killing a lot of trees, especially in the Sierra Nevada along highways 80 and 50 to Lake Tahoe. The dead trees on the roadside was all the evidence they needed.
3) You don't have to be constantly reapplying sand several times a day, which you have to do with salt.