Colorado Winter Traction Law & Winter Tire Laws for Mountain Living

Colorado is the fourth snowiest state in the U.S., averaging 67.3 inches of snow a year, behind Vermont, Maine and New Hampshire (USA.com). But what differentiates Colorado's snowy winters from other states is its ranking as the most mountainous state in the country. The combination of heavy snow and steep terrains makes driving in Colorado winters treacherous, which is why drivers in Denver and other parts of the Rocky Mountains look for information about winter traction laws, tire chain laws and studded tire laws. 

SHOP SNOW TIRES NOW

Not all states allow tires with studs or chains. According to US Tire Manufacturers Association*:

• Not permitted: 6 states don't allow studded tires (Hawaii, Illinois, Michigan, Minnesota, Mississippi, and Wisconsin).
• Permitted: 7 states permit studs without restrictions (Colorado, Kentucky, New Hampshire, New Mexico, North Carolina, Vermont and Wyoming)
• Permitted with restrictions: The remaining 37 states and D.C. have various restrictions, mostly limiting the use of studded tires to winter months. However, some states have restrictions that vary based on locations. 

We'll explore Colorado's passenger vehicle traction and chain laws more in the next section. Understanding winter driving laws can help keep you safe and avoid expensive violation tickets or, worse, accidents. 

*Laws change all the time; check your state's police or highway patrol website for the latest laws on studded winter tires. 

Colorado's Traction Law

In short, according to the Colorado Department of Transportation, CDOT implements Passenger Vehicle Traction and Chain Laws as necessary according to weather conditions.

Highway signs will inform you when a traction or chain law is in effect. More ways to find out when they are in effect are by checking COtrip.org and traffic/roadway condition alerts.

One thing to remember is that CDOT has the power to implement Passenger Vehicle Traction and Chain Laws on any state highway.

When the Traction Law is in effect, all motorists must have either:

• A four-wheel drive (4WD) or all-wheel drive (AWD) vehicle and tires with 3/16-inch tread depth.
• Tires with a mud and snow designation and 3/16-inch tread depth. (NOTE: You should see the M+S icon on these tires.)
• Winter tires with 3/16-inch tread depth. (NOTE: You should see a mountain-snowflake icon on winter tires.)
• Tires with a manufacturer's rating of all weather and 3/16-inch tread depth.
• Chains or an approved alternative traction device.

Traction laws were updated a few years ago to include the following:

• From Sept. 1 to May 31, the Traction Law is always active on I-70 from Dotsero to Morrison.
• The minimum tread depth for tires on all vehicles increased to 3/16-inch.

Colorado Passenger Vehicle Chain Law 

We covered the Traction Law in the previous section. Now let's look at the Vehicle Chain Law.

CDOT will implement the Passenger Vehicle Chain Law during severe winter storms. This is the final safety precaution before closing a highway.

What that means to you: Every vehicle must have chains or an approved alternative traction device when the Passenger Vehicle Chain Law is in place. If not in compliance, you are subject to the following fines:

• Motorists driving with inadequate equipment when a Traction Law or Chain Law is in effect could be fined more than $130.
• If you block the roadway due to inadequate equipment when a Traction Law or Chain Law is in effect, you could be fined more than $650.

Do winter traction laws apply statewide?

The next logical question is if these laws are applied differently in various areas of Colorado. For example, do they differ from Fort Collins to Aurora?

The answer is no. CDOT can implement Traction and Chain Laws on all state highways.

Do You Need Snow Tires in Colorado?

Certain tires are safer when driving on snow or ice because they offer better traction. According to CDOT, the following tire types are Traction Law compliant as long as they have a minimum tread depth of 3/16-inch.

All-weather tires

These tires are considered safe in winter, particularly with heavy rain, slush or wet snow. Tread patterns in all-weather tires provide extra traction and stability. At the same time, rubber compounds allow the tire to stay flexible for various temperatures for grip on wet and snowy roads and dry asphalt. Thus, all-weather tires are OK year-round.

Check out these brands for all-season/all-weather tires

• Yokohama Avid Ascend
• Nexen N'Fera AU7
• Goodyear Assurance WeatherReady
• Toyo Celsius

Winter tires

These tires are safest for snowy and icy conditions and are recommended for driving in winter weather. The tread patterns provide extra traction and stability, while rubber compounds help the tire stay soft in cold temperatures for exceptional grip. All winter tires will have a mountain/snowflake icon and an M+S icon.

Check out these all-terrain winter tires:

• Multi-Mile Wild Country XTX Sport 4s
• Sumitomo Encounter AT
• BFGoodrich All-Terrain T/A KO2

Mud and snow tires

M+S tires are all-season tires that provide better starting, stopping and driving performance in snowy conditions than non-M+S tires. These tires are acceptable in light snow, but are limited to the capabilities of winter tires. 

Check out these M+S tires:

• Michelin Defender LTX M/S
• Cooper Discoverer M+S

What About Studded Tires?

Studded tires are winter tires fitted with cleat-like protrusions that provide more grip than snow tires. Some snow tires come fixed with studs, while others are called "studdable," meaning they have divots where you can install studs on snowy and icy days.

Not all states allow studded tires. Colorado has no restrictions on studded tires, but you might want to learn more about these tires before buying them: Check out our article that explains the difference between snow and studded tires here.