Chain law checker by state: will you need chains?

Chain laws catch more drivers than they should because every state writes its own. One state wants chains on board all season on certain highways; the next only when signs go up; a third has no truck rule at all. This chain law checker by state looks up the rule for the state you are driving in, your truck's weight rating and the month, and links that state's live road report so you can check conditions before you climb.

Semi truck chain laws by state

We check each state's rule against its DOT, statute or state police page and date it. States fall into three groups:

• Carry in season: Colorado, Washington and Montana require trucks to carry chains during set months on listed routes, and to chain up when the law is called.
• Chain up when posted: California, Oregon, Nevada, Idaho, Utah and Wyoming require chains or traction devices when controls are posted.
• Allowed: Arizona allows chains in snow or ice but has no truck-specific mandate we could find.

Every other state shows as not yet verified until we check its official source. Local and temporary orders can apply on top of any state rule. The full map and table sit under the tool, with a CSV download.

Colorado's rule grew recently. CDOT says its must-carry law now covers about 1,400 centerline miles on sections of I-70, Highway 9 and US-40, 50, 160, 285 and 550, from September 1 to May 31, for commercial vehicles over 16,000 lb.

POSTED: Colorado DOT, Colorado's Must Carry Law (Oct 21, 2025) · checked Oct 2026

Truck tire chains

Heavy duty truck tire chains have to fit the tire and meet the state's rule. A few habits help:

• Match the size on your drive tires, and fit chains once in the yard before you need them on a shoulder.
• Know the axles. States differ on how many drive tires to chain and whether a trailer axle needs chains too.
• Check traction devices. Some states accept approved alternatives to chains; others accept only listed products.

How it works

1. Pick the state you will drive through, your weight rating and the month.
2. The tool reads the state's rule: the weight it starts at, any carry season and the routes it covers.
3. It returns a status: carry now, carry in season, chain up when posted, allowed, below the truck rule, or not yet verified.
4. It links the live road report for that state, which is what decides whether chains go on today.

What a good result and a bad result look like

A good result is knowing the rule before you leave and checking the state's live report before each pass. A bad result is finding a chain control at the bottom of a grade with no chains, or chaining up on a narrow shoulder in the dark. Plan the climb for daylight where you can, and know where the chain-up areas are.

Winter runs touch other rules too. Many states also limit idling, covered in idling laws by state, and the big truck stop brands along mountain corridors, listed in our list of truck stop chains, are where most drivers buy chains and wait out closures. Check your axle weights with the truck weight limit checker, and wide loads with the oversize load checker.

Your call on mountain runs

A mountain lane in January is a different job from the same lane in June. Our dispatchers plan loads around your hours and home time, show you the route before you say yes, and never push a run you are not comfortable with. You confirm every load and the rate con comes to you. See how it works for owner operators, or apply in about two minutes.