The more tread a tire has, the safer it will be in hazardous driving conditions. Many states require a minimum of 2/32 inch of tread. For driving in snow, it is advisable to have no less than 5/32 inch.
A tire that works well in dry driving conditions may not work well in wet weather. Snow tires are designed specifically to work when driving in snow, slush or on icy roads. By design all-weather, or all-season, tires are made to provide acceptable, not optimal, performance at extreme temperatures, which means they are not ideal for driving in snow. All-season tires harden in cooler weather, whereas the rubber compound used in snow tires remains more flexible, increasing the ability of the tire to maintain contact with the road.
Some states regulate the use of snow tires. In Colorado, the "chain law" provides two levels of tire requirements for driving in heavy snow. At level one, drivers must use snow tires or adequate traction devices, such as chains. Snow tires must be rated for mud or snow by the manufacturer. Level two, for heavier snow coverage on roadways, requires the use of steel-link chains or, if the vehicle is so equipped, four-wheel drive. Violators can be fined as much as $500 if their violation results in a highway blockage.
