I've taught winter driving for 20 years, and you just can't give advice on how to drive in these conditions. If your car is slowly sliding down the street SIDEWAYS -- from gravity alone -- it doesn't really matter if you're braking or accelerating or turning the wheel this way or that. All of those things require traction, and if it's just not there, it's just not there. Chains help, sure, but the best thing you can do is leave your car parked.