Winter Driving Tips - Chain Controls

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Chain Controls

Before driving, check with the Caltrans Highway Information Network (CHIN):  800-427-7623 and Caltrans Quickmap: Caltrans QuickMap

Chain Installation

You must stop and put on chains when highway signs indicate chains are required. You can be cited by the California Highway Patrol and fined if you don't. You will usually have about a mile between "Chains Required" signs and the checkpoint to install your chains.

  • Control areas can change rapidly from place to place because of changing weather and road conditions.
  • The speed limit when chains are required is 25 or 30 miles an hour.
  • When you put on chains, wait until you can pull completely off the roadway to the right. Do not stop in a traffic lane where you will endanger yourself and block traffic.
  • Chain Installers: If you use the services of a chain installer, be sure to get a receipt and jot the installer's badge number on it. Remember, chain installers are independent business people, not Caltrans employees. Having the badge number may help with any misunderstandings later. Chain installers are NOT allowed to sell or rent chains.
  • When removing chains, drive beyond the signs reading "End of Chain Control" to a pull-off area where you can safely remove them.

The California Department of Transportation (Caltrans) does not sell nor recommend specific brands of tire chains. It is best to check your vehicle manufacturer's specifications for use of tire chains/traction devices.

Chain Installation Chart depicting the proper placement of traction devices for all vehicles.

Guidelines for Chain Control

Chain Requirement Levels

During the winter months, motorists may encounter traction chain controls in the mountain areas within California. When chain controls are established, signs will be posted along the road indicating the type of requirement. There are Three Levels of Chain Requirements in California:

  • Requirement 1 (R-1): Chains are required on all vehicles except passenger vehicles and light-duty trucks under 6,000 pounds gross weight and equipped with snow tires1 on at least two drive wheels. Chains must be carried by vehicles using snow tires. All vehicles towing trailers must have chains on one drive axle. Trailers with brakes must have chains on at least one axle.
  • Requirement 2 (R2): Chains or traction devices2 are required on all vehicles except four wheel/ all wheel drive vehicles with snow-tread tires on all four wheels.
    NOTE: (Four wheel/all wheel drive vehicles must carry traction devices in chain control areas.)
  • Requirement 3 (R3): Chains or traction devices are required on all vehicles, no exceptions.

Truckers, see our Truck Chain Requirements page.

R-1 and R-2 are the most common conditions. A highway will often be closed before an R-3 condition is imposed. Some local areas may use variations of these designations. You must follow the directions on the signs posted for chain controls or any instructions given by Caltrans or CHP personnel at chain control check points, even if these are at variance with broadcast road condition reports or information contained herein.

1 Snow-tread Tires: The California Vehicle Code, Section 558 defines a snow-tread tire as follows, "A 'Snow-tread tire' is a tire which has a relatively deep and aggressive tread pattern compared with conventional passenger tread pattern". Snow-tread tires can be identified by examining the sidewall of the tire where the letters MS, M/S, M+S or the words MUD AND SNOW have been stamped into the sidewall.

2 Tire Traction Devices: The California Vehicle Code, Section 605 defines tire traction devices as follows: "Tire Traction Devices are devices or mechanisms having a composition and design capable of improving vehicle traction, braking and cornering ability upon snow or ice-covered surfaces. Tire traction devices shall be constructed and assembled to provide sufficient structural integrity and to prevent accidental detachment from vehicles. Tire traction devices shall, at the time of manufacture or final assembly, bear a permanent impression indicating the name, initials or trademark of the assembling company or primary manufacturer, and the country in which the devices were manufactured or assembled in final form."

The full, searchable version of the California Vehicle Code is available at: Leginfo, the website for California Legislative Information.

PLEASE NOTE: THE CALIFORNIA DEPARTMENT OF TRANSPORTATION (CALTRANS) RESERVES THE RIGHT TO PREVENT ANY VEHICLE FROM ENTERING A CHAIN CONTROL AREA WHEN IT IS DETERMINED THE VEHICLE WILL EXPERIENCE DIFFICULTY IN SAFELY TRAVELING THE AREA.

Caltrans Highway Information Network (CHIN)

Caltrans officials urge you to check road conditions often. To help keep abreast of changing conditions, Caltrans operates the Caltrans Highway Information Network which motorists may telephone 800.427.7623 for up-to-the-minute information in California and Western Nevada (Lake Tahoe/Reno Area). The network is updated as conditions change, and is voice-activated for safety and convenience.

Before driving, check with the CHIN:  800-427-7623

Caltrans QuickMap

See Caltrans QuickMap for a real-time, zoom-able California map of current traffic conditions including lane closures, CHP incidents, changeable message signs, chain controls, video cameras and more:

Caltrans QuickMap




Statewide Alerts and Other Information

Contact Information

General Information:

General Information Line: (916) 654-2852

Media Inquiries:
Find your local Caltrans media contact on our
Public Information Officers page
or call our
Media Line: (916) 657-5060.

Submit a Customer Service Request

You can also call
1-800-427-7623
for current highway conditions or find more information about roads, traffic and travel on
Caltrans' Travel page.

Physical Address:

California Department of Transportation
1120 N Street
Sacramento, CA 95814

Mailing Address:

California Department of Transportation
1120 N Street
MS 49
Sacramento, CA 95814

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