Bottom Line
Chain Q&A

How do I get information on weather and road conditions reliable enough to make good decisions?
The Weather Channel, NOAA weather radio, 5-1-1 phone and Internet services in conjunction with local radio stations are all sources of current weather information. 

Mountain passes have additional information sources. Truck stops on either side of major passes have pass boards at the fuel desk. Local authorities fax current conditions for posting on the board. 

Some states such as Oregon have live road cams of the passes showing at the truck stops. 

Idaho broadcasts pass conditions on CB Channel 19.

How do I know when to chain up?
On relatively level ground, the decision whether to chain up or not is usually yours alone, assuming the location you’re operating in allows the use of chains. 

Your decision process should include asking yourself several questions:

  • How far or how long will I need to use chains?
  • If I can travel only at 25 mph or less, is it worth it, or should I sit and wait?

Remember, highway maintenance workers take a lot of pride in quickly getting the highways in good driving condition after a storm. 

Mountain pass situations are a little different. Conditions change so fast in higher elevations, communication will be in the form of road signs informing drivers of current chain requirements.

Where am I allowed to chain up?
Chain-up areas will vary from a wide spot on the roadway to well-lit parking areas. Some locations go so far as to have a DOT officer inspect your chain installation to make sure you have done an adequate job before allowing you to proceed.

How do I decide where to put chains?
There are about as many chain laws as there are states that expect commercial drivers to use chains.

Use the truck diagram (below) to match up what tires require chains in each state.


Tire traction devices are defined as devices or mechanisms having composition and design capable of improving vehicle traction, braking and cornering ability upon snow- or ice-covered surfaces.

Drivers are notified of traction device controls by signs along the road. There are three levels of control, R1, R2, and R3. Any of these conditions mean the same thing for a truck driver. If you do not stop until conditions improve, install your traction devices. Maximum speed limit when chains are required is 25 mph. Trucks with cable chains are legal in California. However, these trucks may be restricted at times because of local conditions. Tires requiring chains are A, B, C, D, E, H, M and P.

Colorado drivers are notified of chain law status by signs along the road. There are two levels of chain laws: 

Level 1, Code 17 means single drive axle, combination commercial vehicles must chain up all four drive tires. Note: Cables are not allowed. All other commercial vehicles must have snow tires or chains.

Level 2, Code 18 means chain up is required for all commercial vehicles. Outside tires of one drive axle have chains; other tires may be any cable. Alternate traction devices may be used instead of chains. Wheel sanders, pneumatically driven chains and cables (in certain situations) are all ATDs.

Two approved situations for cables use are:

Tire cables constructed with high-strength steel spring cross member rollers that are at least 0.415-inch or greater in diameter can be used instead of chains.

On tandem-power driver-axle commercial vehicles: Any type cable may be used, but only if there are chains on the outside tires of one of the power drive axles and cables on two or more tires of the other drive axles.

Idaho has no chain law. However, there are times when chains are required. Signs will be posted “Chains required beyond this point” when the road is snow-covered or icy.

Chains must be used when indicated by signs. Minimum requirement: chain tires on drive wheels of one axle.

Nevada has no specific law for or against cable chains. Chains must be of proper size for your tires. Traction devices may be metal, plastic or a combination thereof, and must provide additional traction to the wheels or to slippery surfaces. Drivers are notified of chain-up requirements by signs along the road: “When lights are flashing, chains or snow tires required.” Vehicles over 10,000 pounds GVW must use chains on two drive wheels and two braking wheels of the trailer.

Acceptable chains include link chains, cable chains or other devices that attach to the wheel, vehicle or outside of the tire and that are designed to augment traction. The DOT has the discretion to require the use of link chains only, rather than cable chains, when warranted. Drivers are notified of chain law status by signs along the road. Tires requiring traction devices are A, B, C, D, I and P (any two trailer wheels, either axle and either side) or A, D, E and H (if both axles are drive axles).

South Dakota
South Dakota highways may be posted restricting traffic to vehicles with chains. Notice of travel restrictions will be announced conspicuously on signs. there are no requirements for placement of chains. Use of cables is not prohibited.

Utah has no specific law that chains must be carried. However, carrying one set of chains for the drive axle is suggested from Nov. 1 to March 31. Drivers are notified of chain-up requirements by signs along the road.

Commercial vehicles must carry chains when traveling on many Washington roads from Nov. 1 to April 1. All vehicles over 10,000 pounds GVW must carry two extra chains. Cables are approved. Plastic chains are not approved. Drivers are notified by signs along the roadway. If signs read “approved traction tires required” or “chains required,” vehicles over 10,000 pounds GVW must use chains. Tires requiring traction devices are A, B, C, D and P (one tire, either side of trailer) or A, D, E, H and P.

From time to time, Wyoming travel may be restricted to all-wheel drive vehicles or motor vehicles equipped with tire chains. Drivers are notified of chain law conditions by highway signs and local radio broadcasts. There are specific laws that address the use of cables or the number and placement of chains.

Have a safe trip and enjoy the ride.

Don & Debbe Morrow, authors of the state-by-state guide for truckers, “For the Long Haul,” can be reached