As winter approaches and the weather turns chilly, truckers who travel in California often have questions about the state’s chain requirements.

See information from the Caltrans website below on California chain requirements.

What are the dates when California chain law goes into effect?

California does not have any specific dates when vehicles are required to carry chains. When the road is posted with a sign requiring chains, all heavy-duty vehicles (over 6,500 pounds gross weight) must be equipped with chains mounted on the tires in order to proceed. Depending on the severity of road conditions, some vehicles (passenger cars, 4-wheel drive vehicles with snow tires) may not be required to install chains at that point. The exceptions will be posted on the sign.

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 these higher elevations when conditions warrant.

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

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

Are combinations consisting of a 2-axle tractor (single drive axle) and double trailers prohibited from chain control areas?

There are some areas where such combinations are prohibited when chain controls are posted. These routes are marked with posted signs indicating the restriction.

Are chains required on the inside “duals” on 2-axle vehicles (trucks, buses, RVs, etc.)?

Not usually, but under severe conditions, the California Department of Transportation (Caltrans) may require chains on the inside duals if conditions warrant. (If conditions are this severe, it may be better to postpone the trip.)

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 does it mean when the radio road information says “trucks are being screened?”

During inclement or unsettled weather conditions, Caltrans may set up truck screening check points at approaches to major mountain highways. When these screens are present, all heavy-duty trucks must stop and show Caltrans personnel that they have the required chains on board to proceed. Trucks without chains will be directed to return to a lower elevation until weather improves. There is no room available at higher elevations to park trucks not equipped with chains.

If I have snow tires on a heavy-duty commercial vehicle, do I need to carry chains?

Yes. There is no exemption for heavy-duty commercial vehicles (over 6,500 pounds gross weight) equipped with snow tires. Chains must be installed on heavy-duty commercial vehicles whenever chain controls are posted.

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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