Understanding Chain Laws by State

As a commercial truck driver, failing to comply with state chain laws can result in massive fines, tow bills, or worse-a severe accident. The frustrating part? Every state has its own unique set of rules.

Here is a breakdown of what you need to know about chain laws in the most strict states.

Colorado (I-70 Corridor)

Colorado has some of the strictest chain laws in the country, especially along the I-70 corridor between Denver and Vail.

• Commercial Vehicle Chain Law (CMVTI): Between September 1st and May 31st, all commercial vehicles traveling on I-70 between Dotsero (Milepost 133) and Morrison (Milepost 259) must carry sufficient chains to be in compliance, regardless of the weather.
• When Active: When the chain law goes into effect, you must chain up. Fines for not carrying chains are $50 plus surcharges. Fines for not chaining up when required can exceed $500, and if you block the highway because you didn't chain up, the fine jumps to over $1,000.

California (Donner Pass / I-80)

Caltrans doesn't mess around when it comes to chain controls over Donner Pass.

• California uses a tier system (R-1, R-2, R-3). For commercial trucks over 10,000 lbs, you are most concerned with R-1 and R-2.
• R-2 Condition: This is the most common chain requirement for trucks. You must chain up the drive axles. If pulling a trailer, you must also chain one axle of the trailer (typically the rear axle).
• Caltrans strongly enforces carrying chains during winter months in mountain areas.

Wyoming (I-80)

Wyoming's I-80 is infamous for wind and ice.

• Wyoming has a two-tier chain law.
• Level 1: Conditions are hazardous. Tire chains are required for commercial vehicles.
• Level 2: Extremely hazardous. If Level 2 is enacted, it means the road is effectively closed except for vehicles with chains, but often Wyoming DOT simply closes the interstate entirely rather than jumping to Level 2.

How to Prepare

1. Practice Chaining Up: Don't let a blizzard on Vail Pass be the first time you take your chains out of the bag. Practice putting them on in a dry parking lot.

2. Inspect Your Chains: Check for broken links, rust, or twisted cross-chains before the season starts.

3. Bring Bungee Cords: Chain tensioners or heavy-duty bungee cords are essential for keeping chains tight against the tire.

Always check the Trucker Route 511 Map for real-time chain law requirements before heading into the mountains.