Some reasons for using studded snow tires are that they provide better traction on icy roads and can keep a vehicle from sliding during the winter. The tires have strong metal pieces that dig into ice, which can lead to a very noisy ride.
Studded tires are better for icy roads than snowy roads. The tires are very suitable for people who live near coasts because the roads tend to be icier. Studded tires can, however, damage the road and lead to safety problems, hence the reason why studded tires are outlawed in some states. People deciding to stud their cars should base the decision on the type of weather they expect to face.