California Chain Requirements

Chain Requirements

Chain Requirements (PDF) - diagrammed instructions for applying chains to your vehicle
Chain Controls - types of chain controls and snow-tread tire information
Road Conditions - current road conditions, including chain requirements

Where are chains required?

Chains are most often required in the higher mountain passes of northern California, such as Interstate 5 north of Redding, Interstate 80 over Donner Pass between Sacramento and Reno, Nevada, and US Highway 50 over Echo summit between Lake Tahoe and Sacramento. Chains are also sometimes required on State Route 58 near Tehachapi between Bakersfield and Mojave, Interstate 15 over Cajon Pass between Victorville and San Bernardino, and Interstate 5 over Tejon Pass between Los Angeles and Bakersfield. However, snow can fall unseasonably at higher elevations at many locations within California. Chains may be required at any time at thesehigher elevations when conditions warrant.

Motorists are advised to check the Caltrans website for current road conditions. Motorists may also call the Caltrans road information number at 800-427-7623.

Are “all-weather” or “all-terrain” tires the same as “snow” tires?

They may be. Snow tires have the designation “Mud & Snow” or an abbreviation such as “M-S,” “M+S,” or “M/S” marked on the tire sidewall. Tires without this designation are not considered snow tires. Snow tires must also have at least 6/32-inch (3/16”) of tread depth (about 1/2 of the original tread depth).

Are cable chains permitted?

Usually. They are permitted for passenger cars and light trucks under virtually all conditions. Cables are not as effective as link-type chain under severe conditions at higher elevations and steep grades for “big-rigs” and may not be permitted depending on local conditions as determined by Caltrans. Whenever chain controls are posted over Donner Pass on Interstate 80, heavy trucks are usually required to have link-type chain on at least the main drive axle.

Must chains be carried in exempted vehicles?

Vehicles without chains are not permitted to enter chain control areas and must return to a lower elevation where chains are not required. There is no provision to park vehicles at chain control check points.

What are the dates for studded snow tires?

Studded snow tires are permitted in California from November 1 until April 30 each year. During this time, studded tires are permitted in any location within the state. Studded snow tires are not considered tire traction devices and may not be used in lieu of chains.

If I have 4-wheel-drive, do I need to carry chains?

Yes. Even though weather conditions may not warrant the use of chains on 4-wheel-drive vehicles at a particular time, to enter a chain control area, you must have a set of chains (for one drive axle) for your vehicle in your possession. If conditions worsen or you have trouble controlling your vehicle, you must stop and install the chains.

If I have snow tires, do I need to carry chains?

Yes. Even though weather conditions may not warrant the use of chains on passenger vehicles equipped with snow tires at a particular time, to enter a chain control area, you must have a set of chains (one pair) for your vehicle in your possession. If conditions worsen or you have trouble controlling your vehicle, you must stop and install the chains.

If I have studded snow tires, do I need to carry chains?

Yes. Studded snow tires are not considered tire traction devices and may not be used in lieu of chains.

Is “all-wheel drive” the same as 4-wheel drive?

Yes. Even though all-wheel drive systems may differ mechanically from conventional 4- wheel drive systems, for the purposes of chain control, all-wheel drive is considered the same as 4-wheel drive.

The manufacturer of my vehicle recommends that chains not be installed on it. Do I still have to put on chains?

Yes. Many vehicles which will not accommodate conventional link-type chains will accommodate cable chains or other devices such as “Spikes Spider.” If your vehicle is not equipped with some type of tire traction device, it is neither safe nor lawful for you to enter a chain control area. If you choose not to install tire traction devices on your vehicle, you may not enter a chain control area.

Which axle do I install the chains on?

Chains must be installed on the drive axle. All-wheel drive vehicles and 4-wheel drive vehicles may have chains installed on either drive axle, but the rear axle is preferred, unless the vehicle manufacturer recommends the front axle.

Do I have to put on chains when I am towing a trailer?\

Yes, always.

Even if I have 4-wheel drive?

Yes.

Do I have to put chains on the trailer?

You must have at least one axle chained if the trailer is equipped with brakes.

What are the R-1, R-2 conditions that I hear about?

Although Caltrans does not post signs with these designations nor use them to announce chain controls to the public, they are used internally within Caltrans and the CHP as a kind of shorthand to describe chain restrictions and may be included in traffic reports disseminated by various news outlets.

There are three primary categories of chain restrictions, as shown below:

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 tires 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 (R-2): Chains are required on all vehicles except four-wheel-drive vehicles under 6,500 pounds gross weight and equipped with snow tires on all four wheels. Chains for one set of drive wheels must be carried by four wheel-drive vehicles using snow tires.

Requirement 3 (R-3): Chains are required on all vehicles without exception.

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.

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