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FAQs for Chain Law Traction Bill HB 1207

Starting Aug. 2, 2019, the legislation updates requirements for drivers using state highways during winter months.

Specifically, it changed the required minimum tire tread for vehicles on snowy roads to 3/16 of an inch. The statute also says that the minimum tire tread for dry roads is 2/16 of an inch.

The law reaffirms the department's ability to close state highways during inclement weather, and requires any motor vehicle to have one or more of the following:

  • tire chains;
  • an alternative traction device;
  • four-wheel drive with adequate tire tread;
  • all-wheel drive with adequate tread; and/or
  • tires with manufacturer marking for snow/mud and adequate tread.

The major change is that these requirements for adequate tire tread and traction control devices now apply to passenger vehicles, whereas they did not before.

This means every vehicle traveling on state highways must have adequate tire tread and traction-control devices in their vehicle during inclement weather and snow events.

While the bill specifies the I-70 mountain corridor between Genesee and Dotsero, this does not limit the applicability of the law to this corridor. CDOT traction and chain law apply to all state highways. The legislation speaks to the I-70 corridor because it is a critical highway to keep open, and because the high number of spinouts and crashes that occur along this road between September and May.

The Colorado State Patrol (CSP) will not proactively enforce the tire tread-depth requirement on vehicles for the following reasons:

  • There is language in the bill that states the tire tread and traction-control device requirements are in place when there are icy and snow-packed conditions.
  • During clear, dry conditions, the existing 2/16-of-an-inch tread applies.
  • The CSP has neither the manpower nor the resources to enforce tire tread requirements on all vehicles traveling state highways during snow events.

There is language in the bill that directs CDOT and the CSP to meet with stakeholders to discuss options and ideas on how to begin enforcing this law along I-70. Obviously, there are many implications associated with increased enforcement, including:

  • slowing down traffic further on the east side of Vail Pass and at Genesee;
  • resources for enforcement actions;
  • whether there will be additional chain-up stations available for vehicles without traction control devices; and
  • when, where and how possible chain stations will be staffed and funded.

It may be possible to increase enforcement before next winter, but many policy and fiscal questions remain unanswered at this time as to be able to adequately say when and where additional enforcement would occur.

Additional Traction and Chain Law FAQs

Most all-terrain tires meet the tire requirement, but double-check yours to make sure. You'll want to look for a mud and snow rating ("M+S" or "M&S") or snowflake icon on the sidewall of the tires.

During an active Traction Law, you can put on chains or an alternative traction device (like an AutoSock) and be in compliance with the law. Be sure to only pull over at designated chain up areas to stay safe.

No. An alternative traction device is something like the AutoSock. Under an active Passenger Vehicle Chain Law, every passenger vehicle will need to have chains or an alternative traction device equipped.

Most "snow" tires will be designated with a snowflake symbol AND an M+S mark on the tire. Some all-season/all-weather tires have a mud and snow rating, and that is designated with the M+S mark. Any tires with a snowflake or M+S mark comply with the Traction Law, as long as all the tires have a minimum one-eighth inch tread.

To be an approved tire under the Traction Law, they will need to have a snowflake mark (designating a snow tire) or a mud and snow (M+S) mark — all tires must have a minimum one-eighth inch tread. If you drive a four- wheel drive or all-wheel drive vehicle, all of your tires just need to have a minimum one-eighth inch tread.

Yes to both questions. During a Passenger Vehicle Chain Law, every passenger vehicle must be equipped with chains or an alternative traction device (like an AutoSock). If you are driving without the proper equipment, you could be fined more than $130. If you block the roadway because you don't have the proper equipment, you could be fined more than $650. If you aren't carrying chains or a traction device with you, you will be required to wait until the chain law is lifted.

Both laws apply to the entire state, but during the 2015/16 winter, you'll likely only see if called along the I-70 Mountain Corridor and connecting highways. During the 2016/17 winter, you will see the law activated along all interstates and state highways.

There is no "limp home" provision under either law. If you do not have the proper equipment during either law, you can be fined and restricted from the roadway for not only your safety, but also the safety of those around you. The best thing to do is make sure you have safe tires for winter driving and carry chains or an alternative traction device (like an AutoSock) in your vehicle at all times.

Tires and Chains FAQs

To be an approved tire under the Traction Law, they will need to have a snowflake mark (designating a snow tire) or a mud and snow (M+S) mark — all tires must have a minimum one-eighth inch tread. If you drive a four- wheel drive or all-wheel drive vehicle, all of your tires just need to have a minimum three-sixteenths inch tread.

An adequate tire under the Traction Law needs to have a minimum three-sixteenths inch tread on all four tires. If you're not in a four-wheel or all-wheel drive vehicle, those tires need to be snow tires or have a mud & snow (M+S) rating.

You always want to put chains or alternative traction devices (like an AutoSock) on the "drive" wheels of the vehicle. You would install them on the front wheels of a front-wheel drive vehicle or on the rear wheels of a rear-wheel drive vehicle. On a four-wheel drive or all-wheel drive vehicle, the chains or alternative traction devices are generally used on just the rear wheels, but to retain as much of the normal handling characteristics as possible, chains should be installed on all four tires.

All-wheel drive and four-wheel drive are not the same, but under the Traction Law, both are compliant as long as all the tires have a minimum one-eighth inch tread. While all-wheel drive and four-wheel drive are great for getting going in slick or snowy conditions, when it comes to stopping, nothing is more important than your tires. In winter conditions, snow tires stop much more quickly than all-season tires. For more information about tire stopping distance, head to winter.codot.gov/tires.

To learn about the difference between all-wheel and four-wheel drive, keep reading.

There are two main kinds of four-wheel drive — part-time and full-time. With part-time four-wheel drive, most vehicles are rear-wheel drive until the driver manually puts the vehicle in four-wheel drive. With full-time four- wheel drive, all four wheels are always engaged.

With all-wheel drive, sensors automatically determine which wheels should get power to maximize traction. During normal conditions, most all-wheel drive vehicles use just the front wheels.

All that said, a front-wheel drive vehicle with snow tires will perform better than an all-wheel or four-wheel drive with all-season tires in nearly any turning or stopping situation. The key takeaway is that tires mean everything when it comes to stopping. Click here to see a video showcasing this fact.

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