To describe the stud's effectiveness, I'll use an analogy. Think about walking with rubber soled shoes on three surfaces; dry clean asphalt, glare ice, and glare ice that's been sprinkled with sand. On the dry asphalt you can run and make sharp turns without any concern about your shoes skidding. On the ice, you can only walk carefully, changing direction and speed slowly, lest you Fall Down Go Boom (that's FDGB for those of you, "in the know" so to speak). On ice that someone has nicely sprinkled some sand over, you can walk easily and perhaps even run. But if you do run you won't be making any sharp turns or trying to stop quickly, as you would on dry asphalt, since you know full well that those little grains of sand aren't glued onto the ice, and can roll if pushed hard enough.

Riding on ice with studded tires is like walking on ice that's been lightly covered with sand. It's pretty safe. You're not likely to fall unless you do something stupid. You're not going to have the same traction you would have on dry pavement. But you're going to have far more than you would with regular tires on ice. Keep in mind that there's ice down there and you'll be fine. Try to be a hero, and you'll probably pay a price.