Snow zone signs inform motorists about the current requirements for chains and traction tires. Normally, three messages may be displayed on these signs throughout the winter months.
1. Carry Chains or Traction Tires
When signs say you must carry chains or traction tires, the chains or traction tires must be in or on your vehicle, and they must be the right size for your vehicle and of sufficient number to comply with the chain rules.
2. Chains Required on Vehicles Towing or Over 10,000 GVW
When this message is displayed, vehicles towing or rated for more than 10,000 pounds GVW (gross vehicle weight) must use chains.
3. Chains Required-Traction Tires Allowed on Vehicles Under 10,000 GVW
Vehicles towing or rated for 10,000 pounds GVW must use chains. Vehicles weighing 10,000 pounds GVW or less and that are not towing must use chains or traction tires.
Chains include link chains, cable chains, or any other device that attaches to the wheel, vehicle, or outside of the tire that is specifically designed to increase traction on ice and snow.
Traction tires include studded tires or other tires that meet tire industry standards for use in severe snow conditions. Studless traction tires that meet Rubber Manufacturers Association standards for use in severe snow conditions carry a special symbol on the tire sidewall: a three-peaked mountain and snowflake. Research shows these tires provide better traction than studded tires on bare pavement.
When towing, cars and light trucks must use chains on both tires of the drive axle. Chains also must be on the two outside tires of at least one axle of a trailer that is equipped with a brake.
In most winter conditions, four-wheel and all-wheel-drive vehicles are exempt from the requirement to use chains or traction tires if the vehicle is not towing.