Chain law checker by state for trucks

This chain law checker by state returns the official chain control source for each western state, the commercial vehicle rule where we have verified it, and a list of what to carry.

Chain laws are one of the few rules a truck driver can face that change by the hour. A pass can go from dry to chain control in one storm, and the requirements depend on the state, the route, the season and the vehicle. That is why this tool sends you to the official source rather than trying to summarize every rule in one table.

How to use it

Pick a state. The result shows:

• The official source: the state DOT or 511 page where chain controls are posted.
• A verified rule, where we have one: we only state a specific rule after checking it against the state DOT. The date shows when we checked.
• What to carry: a short list that applies everywhere.

Bookmark the result with the copy link button, or print the card and keep it in the truck.

The Colorado rule

Colorado is the state where truckers most often ask about chains, because of I-70 through the mountains. According to CDOT, from September 1 through May 31, commercial vehicles traveling I-70 between the Dotsero exit (mile point 133) and the Morrison exit (mile point 259) must carry sufficient chains to comply with the chain law. When the law is activated, signs say which vehicles must chain up.

Source: Colorado Department of Transportation, checked October 2026

Penalties, chain-up station locations and the details of each control level change over time, so check CDOT before the season and before each trip.

Semi truck chain laws by state: why the rules vary

Each state writes its own rules. Some require trucks to carry chains during a set season on certain routes, whether or not chains are in use. Others only require chains when a control is posted. Many use levels, where a lower level applies to some vehicles and a higher level applies to all of them. Some allow alternatives such as approved traction devices in certain conditions.

The safe approach is to know which states on your route post controls, carry chains that meet the strictest requirement you may face, and check the official source before you go.

Tire chains for trucks: the basics

• Size them to your tires. Chains that do not fit are dangerous and may not count as compliant.
• Practice before the storm. Fit them once in a dry yard so the first time is not on a dark, icy shoulder.
• Chain up only in safe places. Use designated chain-up areas where they exist. Never stop in a travel lane.
• Re-tension after a short distance. Chains loosen as they settle.
• Drive slower. Chains improve traction, not stopping distance on ice. Follow posted speed limits for chained vehicles.
• Remove them when the control lifts. Running chains on dry pavement damages chains, tires and the road.

Our guide to truck tire chains covers fitting, sizing and inspection in more detail.

Before a winter run

Tires matter as much as chains. Check tread depth and pressure; our tire tread depth legal checker shows the federal minimums. The pre-trip inspection checklist covers lights, wipers, defrost and emergency equipment, and the truck maintenance checklist covers the deeper checks worth doing before winter.

Planning a winter route

Chain controls rarely come as a total surprise. Forecasts give a day or two of warning in most storms. Before a winter trip through the mountains, look at the forecast for each pass on the route, check the state road site the night before and again before you reach the grade, and know where the chain-up areas are. If a pass is likely to close, a longer route at lower elevation can be faster than waiting at the bottom. Build extra time into the delivery appointment, and tell the broker early if weather may delay the load.

What we do not do

We do not give legal advice, and this tool is not a substitute for the posted signs or the official state source. Rules change, and enforcement is up to each state. When the sign and this page disagree, follow the sign.

Where we fit

Our dispatch desk plans loads across the West with chain laws and pass closures in mind. We find and negotiate the load, you say yes, counter or no, and the broker sends the rate confirmation to you to sign. If you run a single truck, our owner-operators page covers how that works.