Rear end car accidents are probably the most common, and happen even easier on icy roads. You also see a lot of accidents where people over-shoot a light or a stop sign, or slide into the oncoming lane.
With slip and falls, on a day like today, parking lots and shopping center sidewalks get icy. On a day like today, the storm itself is over, and stores are under an obligation to exercise reasonable care to prevent slipping. That means salt. Even if the snow didn't stick, If a store's employees don't generously salt the areas where people are walking they are asking for trouble.