2 CCR 601-14
Rules Governing Chain Law and Passenger Vehicle Traction Law Requirements on the State Highway System 

2 CCR 601-14

Statement of Basis and Purpose and Statutory Authority

The purpose of these rules is to describe the travel conditions, types of vehicles, and the locations which require tire chains, adequate types of tires, four-wheel drive or other means to provide adequate traction, when the Department determines such means are necessary to protect the safety of the travelling public and to minimize the occurrence of road closures. The Department revised the rules in order to make them more understandable to the travelling public. It removed the codes used to communicate when chains or snow tires were required and replaced the codes with clearer categories pertaining to Passenger Vehicles and Commercial Motor Vehicles, and updated the rules to current practice. The new rules explicitly refer to "Non-Commercial or Recreational Vehicles" and state that they fall within the specified type of travel restriction depending on the vehicle weight and the road and weather conditions. These changes to the rules reflect the now widespread use of communicating via electronic messaging signs and via other means of technology. 

The rules shall apply to all state highways on the State Highway System as defined in § 43-2-101(1), C.R.S. or as determined by the Transportation Commission. These rules are based on the following statutory sections: § 42-4-106(5)(b) C.R.S. (rule-making authority granted to the Transportation Commission); § 42-4-106 C.R.S. (setting forth who may restrict the use of highways); § 43-2-101(1) C.R.S. (defining State Highway System); § 42-4-214 C.R.S. (setting forth required visual signals on service vehicles), and § 42-4-1701(4)(a)(I)(F) C.R.S. (penalties for non-compliance).

1.00	Definitions

1.01	“Alternate Traction Device" or "ATD" means an approved non-traditional traction device differing from metal chains in construction, material or design but is capable of providing traction comparable to that of such metal chains or cables under similar conditions, which is listed on the CDOT Approved Product List ("APL"). 

1.02	"Authorized Service Vehicles" shall mean such highway or traffic maintenance vehicle as is publicly owned and operated on a highway, by or for a governmental agency, the function of which requires the use of service vehicle warning lights as prescribed by state law and such other vehicles having a public service function, including, but not limited to, public utility vehicles and tow trucks, as determined by the Department of Transportation under § 42-4-214(5), C.R.S. Some vehicles may be designated as both an Authorized Emergency Vehicle and an Authorized Service Vehicle. See § 42-1-102(7) C.R.S.  

1.03	"Autotransport Carriers" means vehicles specifically designed and used for the transport of automobiles. 

1.04	"Chain Law" means the requirement imposed by the Department for all vehicles using certain areas of the State Highway System during periods of adverse road and weather conditions in order to protect the safety of the travelling public and prevent accidents resulting in traffic issues and road closures. Notification of Chain Law requirements shall occur as set forth in Rule 2.02 below, based on assessed road and weather conditions.

1.05	"Colorado State Patrol" shall mean the organization created by § 24-33.5-201, C.R.S.

1.06	"Commercial Motor Vehicle" or "CMV" means a vehicle having a manufacturer's GVWR of at least 16,001 pounds and used in commerce on public highways or a GVWR of at least 16,001 pounds and used to transport at least 16 passengers. § 42-4-235(1)(a), C.R.S.

1.07	"Department" means the Colorado Department of Transportation. 

1.08	“Drive Wheel Tire” means a tire attached to a wheel through which tractive force is transferred from the vehicle to the road causing the vehicle to move. 

1.09	"GVWR" means gross vehicle weight rating. 

1.10	"Motor Vehicle" means the same as defined in § 42-1-102(58), C.R.S. For purposes of these rules, the term Motor Vehicle shall include Passenger Vehicles, Commercial Motor Vehicles and Recreational Motor Vehicles.

1.11	"Non-Commercial or Recreational Vehicle" means a truck, or unladen truck tractor, operated singly or in combination with a trailer or utility trailer or a motor home, which truck, or unladen truck tractor, or motor home is used exclusively for personal pleasure, enjoyment, other recreational purposes, or personal or family transportation of the owner, lessee, or occupant and is not used to transport cargo or passengers for profit, hire, or otherwise to further the purposes of a business or commercial enterprise.” § 42-1-102(61), C.R.S. For the purposes of these rules, Non-Commercial or Recreational Vehicles are categorized by weight as either a Commercial Motor Vehicle or a Passenger Vehicle.

1.12	"Passenger Vehicle" means any vehicle with four or more tires capable of transporting up to 15 passengers and that is less than 16,001 pounds GVWR.  

1.13	"Recreational Motor Vehicle" means the same as "Non-Commercial or Recreational Vehicle." 

1.14	"Passenger Vehicle Traction Law" shall mean the requirement imposed by the Department for Passenger Vehicles using certain areas of the State Highway System during periods of adverse road and weather conditions in order to protect the safety of the travelling public and prevent accidents resulting in traffic issues and road closures. 

1.15	"Variable Message Signs" or "VMS" shall mean the traffic control device electronic messaging signs on the State Highway System used to advise the travelling public through electronic or static means of road conditions and travel requirements including Passenger Vehicle Traction Law or Chain Law. 

2.00	Means of Notification Regarding Road Conditions and Travel Requirements 

2.01	Who May Implement Travel Requirements on state highways.  Any Department maintenance supervisor or their designee shall have the authority to implement the Chain Law or Passenger Vehicle Traction Law. It is within their discretion to determine when road, weather and driving conditions, are such that require the Chain Law or Passenger Vehicle Traction Law to be in effect.

2.02	The applicable Traction and Chain Law requirements will be messaged out through the CDOT notification process, to include official traffic control devices including Variable Message Signs, static signs, official CDOT travel website, telephonic messaging system, email and text notifications and other technologies.  Notifications will specify by mile points and by exit number when chains are required. 

2.03	Chain Law and Passenger Vehicle Traction Law shall be in effect until notice is provided by an official traffic control sign or other CDOT notification, or when the center line or lane lines are visible on a descending grade.

3.00	Passenger Vehicle Traction Law 

3.01	Passenger Vehicles are vehicles under 16,001 pounds gross vehicle weight rating (GVWR) and vehicles capable of transporting up to 15 passengers.  Vehicles that meet these requirements include but are not limited to:

3.01.1	A vehicle towing a trailer or another vehicle;

3.01.2	Non-Commercial or Recreational Vehicles less than 16,001 pounds GVWR; and

3.01.3	Passenger vans (up to 15 passengers).

3.01.4	A Passenger Vehicle can be a two-wheel drive vehicle, an all-wheel drive vehicle or a four-wheel drive vehicle.

3.02	The Passenger Vehicle Traction Law applies to Non-Commercial or Recreational Vehicles under 16,001 pounds GVWR.

3.03	To travel on a state highway when the Passenger Vehicle Traction Law is in effect, a Passenger Vehicle must have either: 

3.03.1	Chains on all drive tires; or 

3.03.2	Cables on all drive tires; or

3.03.3	Alternate Traction Devices (ATD); or

3.03.4	Adequate tires, which shall mean tires with a minimum of a 3/16-inch tread depth, which are:  

3.03.4.1	Snow Tires with a “mud and snow” (M+S, M&S, or M/S) rating;

3.03.4.2	Tires with an all-weather rating by the manufacturer; or

3.03.4.3	Winter Tires (mountain snowflake symbol on the side wall of the tire). 

3.04	The Department recommends that Passenger Vehicles travelling on state highways carry adequate chains or cables or ATD during the months when snow could be encountered. 

4.00	Passenger Vehicle Chain Law 

4.01	Passenger Vehicles include but are not limited to vehicles under 16,001 GVWR and vehicles capable of transporting up to 15 passengers. Vehicles that meet these requirements include but are not limited to:

4.01.1	A vehicle towing a trailer or another vehicle;  

4.01.2	Non-Commercial or Recreational Vehicles less than 16,001 pounds GVWR; and

4.01.3	Passenger vans (up to 15 passengers).

4.01.4	A Passenger Vehicle can be a two-wheel drive vehicle, an all-wheel drive vehicle or a four-wheel drive vehicle.

4.02	The Passenger Vehicle Chain Law applies to Non-Commercial or Recreational Motor Vehicles under 16,001 pounds GVWR.

4.03	To travel on a state highway when the Passenger Vehicle Chain Law is in effect, a Passenger Vehicle must have either: 

4.03.1	Chains on all drive tires; 
 
4.03.2	Tire Cables on all drive tires;

4.03.3	ATDs; or 

4.03.4  Winter tires (mountain snowflake symbol on the side wall of the tire) with a minimum of a 3/16-inch tread depth on a four-wheel drive or all-wheel drive vehicle.

5.00	Commercial Motor Vehicle Chain Law 

5.01	A Commercial Motor Vehicle for purposes of these rules is any vehicle 16,001 pounds GVWR or more and used in commerce on public highways or vehicles 16,001 pounds GVWR or more and has the capacity to carry 16 or more passengers. 

	5.01.1 Non-Commercial or Recreational Vehicles 16,001 pounds GVWR or more shall comply with the provisions of the Commercial Motor Vehicle Chain Law when in effect.

5.02	To travel on a state highway when the Commercial Motor Vehicle Chain Law is in effect, a Commercial Motor Vehicle or Non-Commercial or Recreational Vehicle must have chains or ATDs on at least four of the drive wheel tires, or all of the drive wheel tires if the vehicle has fewer than four drive wheel tires. Buses are required to chain or have ATDs on two drive wheel tires.  See § 42-4-106(5)(a)(I), C.R.S.

5.03	Commercial Motor Vehicles hauling flammable, combustible or explosive materials as defined by federal regulations may continue beyond the Variable Message Sign until they encounter snow on the road.  The driver shall affix chains at the earliest possible time where the traction of the vehicle is compromised (where the pavement is primarily covered by snow or ice) at a safe location outside the travelled portion of the highway.  

5.04	The Commercial Motor Vehicle or Non-Commercial or Recreational Vehicles may proceed beyond the chain area to the next safe location in the event the chain station is full in order to safely affix or remove chains.  
5.05	Passing Requirements when the Commercial Motor Vehicle Chain Law is in Effect. Whenever the Commercial Motor Vehicle Chain Law is in effect, Commercial Motor Vehicles or Non-Commercial or Recreational Vehicles shall be restricted to the right lane unless encountering a stalled or slower moving vehicle that would result in the loss of traction, in which case the CMV or Non-Commercial or Recreational Vehicles may utilize the left or center lane to pass if the movement can be made with safety and without interfering with other traffic. However, the pass must be completed without losing traction and the CMV or Non-Commercial or Recreational Vehicles must return immediately to the right lane upon completion of the pass.

5.06	Autotransport Carriers

5.06.1	Autotransport Carriers shall be exempt from using tire chains on at least four drive wheels in the event the tire chains would jeopardize the safety of the hydraulic lines of the vehicle. 

5.06.2	To the extent tire chains do not interfere with the hydraulic lines, Autotransport Carriers shall be subject to these rules.  

5.06.3	When the Commercial Motor Vehicle Chain Law has been implemented and Autotransport Carriers cannot use tire chains on at least four drive wheels, the use of pneumatically driven chains, drive wheel sanders or ATDs, or use of winter tires (mountain snowflake symbol on the side wall of the tire) with a minimum of a 3/16-inch tread depth shall be required.

6.00	Tire Chains, Tire Cables and Approved Alternate Traction Devices 

6.01	Under certain road conditions, chains, tire cables or ATDs may be required. With regard to Passenger Vehicles, the required use of these traction devices may depend on the type and quality of tire on the Passenger Vehicle.

6.02	Tire Chains. Tire Chains include but are not limited to metal chains which consist of two circular hoops, one on each side of the tire, connected by not less than nine evenly spaced chains across the tire tread. See § 42-4-106(5)(a)(I), C.R.S. Tire chains shall meet the SAE classification as outlined in NACM 92805 (TC) by the National Association of Chain Manufacturers.  

6.03	Clip on chains are not permitted, nor is any other device not designated as an approved ATD.

6.04	Tire Cables. Tire cables are traction devices made of steel cable as opposed to steel chain link, which have high strength steel cross member rollers 0.415" or greater in diameter, which may only be used on passenger vehicles.  

6.04.1	Tire Cables on Commercial Motor Vehicles are not permitted.

6.05	Alternate Traction Devices must be one of the ATD included in the CDOT Approved Product List ("APL"). Drive wheel sanders and pneumatically driven chains are also allowed. 

7.00	Truck Chain Up, Truck Chain Down and Inspection Stations 

7.01	The Department shall designate the locations of chain inspection stations.

7.02	The Department may designate Authorized Service Vehicles to sell, mount, and assist in mounting chains in compliance with these rules at certain chain-up stations. 

7.03	The Department or law enforcement personnel may control the reentry of vehicles from the chain station or inspection station to the state highway in such a manner as to enhance the flow of traffic and assure the safety of the travelling public.

7.04	All vehicles subject to the Passenger Vehicle Traction and/or Chain law applicable at the time may be subject to inspection by Department personnel or appropriate law enforcement personnel for compliance with the chain law or Passenger Vehicle Traction Law before proceeding on the state highway. 

7.05	Passenger vehicles shall chain up at safe locations in rest areas or locations with public access off the main line of traffic.  It is recommended that Passenger Vehicles not affix chains in designated Commercial Motor Vehicle chain up areas.  

7.06	If any vehicle is not in compliance, law enforcement or Department personnel may: 

7.06.1	Hold the vehicle in the inspection or chain area; 

7.06.2	Require the driver of the vehicle to reverse its direction of travel or stop travel; or 

7.06.3	Be required to retain a private towing service to convey the vehicle through the area covered by the chain law implementation.

8.00	Authorized Service Vehicles and Authorized Emergency Vehicles 

8.01	Government Owned Highway Maintenance Vehicles. Government-owned highway maintenance vehicles, in the exercise of highway maintenance activities, or incident management, are exempt from the travel restrictions in these rules. 

8.02	Vehicle Recovery Units. Vehicle recovery units that are in the exercise of clearing travel lanes in a chain law enforcement area shall be exempt from these rules. 

8.03	Authorized Emergency Vehicles shall be exempt from these rules. 

9.00	Penalties

9.01	Persons operating motor vehicles on any portion of the State Highway System that has the Chain Law and/or Passenger Vehicle Traction Law in effect must comply with these rules. 

9.02	A person who operates a motor vehicle in violation of these rules or in violation of restrictions imposed by the Department or the State Patrol shall be subject to fines set forth in § 42-4-1701, C.R.S. 

9.03	An enhanced penalty will be assessed as set forth in § 42-4-1701(4)(a)(I)(F), C.R.S., if the person violates these rules while operating a Commercial Motor Vehicle or where the violation causes a closure of a travel lane in one or both directions. 

9.04	§ 42-4-1701(4)(a)(I)(F), C.R.S., regarding enhanced penalties shall not apply to a tow operator who is towing a motor vehicle or traveling to a site from which a motor vehicle is to be towed. 

10.00 	Declaratory Orders  

10.01	The Department may entertain, at its sound discretion, petitions for declaratory orders pursuant to § 24-4-105(11), C.R.S.

11.00	Incorporation by Reference 

11.01	All referenced laws and regulations shall be available for copying for a reasonable charge or for public inspection during regular business hours from the Office of Policy and Government Relations, Colorado Department of Transportation, 2829 W. Howard Place, Denver, Colorado 80204.

11.02	The following material is incorporated by reference into these rules. Tire Chain Specifications NACM 92805 (TC), adopted by the National Association of Chain Manufacturers on September 25, 2005, and reaffirmed without change on April 12, 2015. Copies of NACM 92805 (TC) may be obtained by contacting The National Association of Chain Manufacturers by phone at (248) 994-2222, or by writing to them at the following address:

The National Association of Chain Manufacturers
28175 Haggerty Road
Novi, MI 48377