you put chains on the drive tires.. the other tires will spin no matter how bad the traction is.. IE you chain the rear on a rwd truck, and the front will turn when you move.. some people want to chain the front so they have better traction to turn & stop. If you need better traction up front for that, drove slower, or get off the road.. Others usually won't have any more traction then you, often less.. so you can stop, they drive up your butt!!!!!