Chain Law Checker by State for Trucks

Chain law checker by state for semi trucks

Pick the state, the month and your vehicle's weight rating. See whether you must carry chains, when you have to put them on, what to carry and what it costs to get it wrong.

By Milo / Updated October 2026

State

Month of the trip

Vehicle weight rating (GVWR or GCWR)

A loaded tractor-trailer is usually rated 80,000 lb

CHAIN RULES / COLORADO / DECRESULT

Covered by the truck rule: Yes, over 16,000 lb
Where: I-70 west of Morrison to Utah, CO-9 Frisco to Fairplay, US-40, US-50, US-160, US-285 and all of US-550 (over 1,400 miles)
When to chain up: Install when the commercial vehicle chain law is activated on signs or COtrip; use designated chain stations.
What to carry: Enough chains or an approved traction device for the drive tires.
Fines: $500 for not carrying chains; up to $1,000 plus surcharge for blocking the road.

Must carry chains nowYES

Red months: chains must be carried on the listed routes. Source: Colorado DOT.

Running Colorado in Dec? Chains go in the truck before you leave. Our dispatchers plan winter lanes around closures and chain-up time, and every rate con comes to you to sign or turn down.

Apply for dispatch

Winter chain laws catch out more carriers than any other state rule, because they change by state, by route and by month, and a fine can arrive before the snow does. This chain law checker covers the five western states where truck chain rules are most strict, with each state's own source linked.

How it works

For each state the checker holds three things from that state's transportation department:

Who is covered: the weight above which the truck rule applies (Colorado 16,000 lb, Washington and Oregon 10,000 lb, Idaho's pass rule 26,000 lb).
Must-carry season: Colorado and Washington require trucks to carry chains for set months on listed routes, snow or not. Elsewhere, chains are required when signs or the state's 511 say so.
Chain-up rules, fines and what to carry, as each state publishes them.

Pick a month and the result shows whether chains must already be in the truck, and the month strip shows the whole season at a glance.

Semi truck chain laws by state at a glance

State	Trucks covered	Must carry	Chain up
Colorado	Over 16,000 lb	Sept 1 to May 31, listed routes	When the chain law is activated
Washington	Over 10,000 lb	Nov 1 to Apr 1, listed passes	When "chains required" is posted
Oregon	Over 10,000 lb	Whenever chains may be needed	When signs require
California	Trucks and anything towing	To enter chain control areas	Under any chain control
Idaho	Over 26,000 lb	Winter, on three passes	When signs are activated

Other states, including Nevada, Utah, Wyoming and Montana, post chain controls when conditions require them. Check each state's 511 before crossing.

Truck tire chains: what to carry

Chains that fit your drive tires, and enough for the axles the strictest state on your route requires.
Spares for broken cross-links; a snapped chain doesn't count.
Gloves, a headlamp, bungees and a tarp to kneel on. Chain-up stations are dark and wet.

Practice once in a dry yard before the first trip. The chain-up you learn on a closed pass at night costs hours, and often a load. Part of a winter truck and trailer inspection is checking the chains are actually there.

Planning winter loads

Chain-ups and closures add hours, so check arrival times with the ETA calculator. Fuel before the climb where taxes are lowest, using the where to fuel calculator. New to running your own truck in the mountains? See power only owner-operator for how loads and lanes come together, and what dispatch costs on dispatch cost.

Rules change, and states can activate chain controls on any road. The checker reflects each source as of October 2026; always follow posted signs.

SOURCES

Questions about this tool

01Which states have chain laws for semi trucks?

Most mountain states can require chains when conditions call for it. Colorado and Washington go further and require commercial trucks to carry chains through the winter on listed routes whether it's snowing or not. Oregon, California and Idaho require trucks to chain up when signs say so.

02What tire chains does a semi truck need?

Heavy duty truck tire chains sized for your drive tires, enough to cover the drive axles the state requires. Washington asks for at least two extra chains, two-sided and metal. California requires one set on a semi-trailer regardless of axles, and super singles need devices on every drive wheel.

03Can I use cable chains or socks on a truck?

Some states accept approved alternative traction devices, and Colorado's law allows them. Others limit what counts for heavy trucks. Check the state's rule before relying on anything but steel chains.

04What happens if I don't carry chains in Colorado?

A $500 fine for not carrying chains when the law requires it, and up to $1,000 plus surcharge if you block the road. Colorado's must-carry rule runs September 1 to May 31 for commercial vehicles over 16,000 lb on over 1,400 miles of mountain highway.