Overview

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  Studded snow tires are used to provide more traction when the driving surface is slippery. Studded tires feature metal studs embedded in the tread of the tire. Colorado invokes a chain law that requires a minimum of snow tires whenever road conditions cause vehicles to slip, particularly on inclines, but allow studded tires all year. There are four levels of chain requirements that affect different types of vehicles, Codes 15, 16, 17 and 18.
  
  

Studded Tires Required

• A Code 15 requires that all motor vehicles traveling on state highways be equipped with studded or un-studded snow tires, chains or alternative traction devices. Four-wheel drive vehicles may travel without snow tires or chains if their tires have at least 1/8 inch of tread and the four-wheel drive is activated. Alternative traction devices include wheel sanders or pneumatic chain devices that deploy chains automatically.
  
  

Chain Only

• Code 16 requires that all vehicles be equipped with chains or alternative traction devices if they are traveling on state highways. Studded snow tires do not provide adequate traction to be included under this code, so a vehicle with studded tires must also have chains in order to travel on the highway.
  
  

Commercial Vehicles

• Codes 17 and 18 apply to commercial vehicles, trucks or buses used to transport passengers or items, and have a gross weight of 26,001 lbs. or more. Code 17 requires all commercial vehicles with only one drive axle to use either chains or alternative traction devices. Larger vehicles must use studded snow tires, un-studded snow tires, chains or alternative traction devices. Code 18 requires all commercial vehicles to use chains or alternative traction devices. Studded snow tires do not provide sufficient traction under this code.