In what circumstance would you increase the following distance in your car?

Rain, ice, snow, fog, bald tires, bad breaks, following semi or trailoring vehicle (jack knife and lock ups can can hard to avoid), and behind sports cars and motorcycles (motorcycles are obvious for fall offs and crashes however both motorcycles and sports cars can stop extremely fast, and unless you are on one of them, you cant), or if you are towing something. All depends on experience and conditions