One Mountain Pass, Five Chain Rulebooks: Western States Should Agree on One

Washington's chain-carry season starts tomorrow. From Nov. 1 to April 1, trucks on posted passes have to carry chains, plus two spares (WSDOT). That's a reasonable rule. So is Colorado's. So is Montana's. The trouble is that they're all different, and a driver who crosses three western states in one shift is expected to know every version.

We built a chain-law guide covering 13 states and British Columbia, linking each rule to the state's own DOT page or statute. Putting them side by side makes the problem obvious.

Same truck, same storm, different rules

When you have to carry chains. Colorado requires commercial vehicles to carry chains on its mountain corridors from Sept. 1 to May 31, whatever the weather (Colorado State Patrol). Montana's season runs Oct. 1 to April 30 for vehicles over 26,000 pounds towing a trailer (MDT). Washington's is Nov. 1 to April 1 on posted passes. Oregon requires carrying chains where signs say so (ODOT). California has no carry season at all. It screens trucks at chain checkpoints when controls are up (Caltrans).

What "chains required" means. California uses R-1, R-2 and R-3 levels, though Caltrans says it doesn't post those codes on signs (Caltrans). Washington, Oregon and Colorado each step up through their own sequence of conditions and wording. A driver who learned one state's ladder has to relearn it at the next border, often at night and in snow.

What it costs to get it wrong. For failing to chain up, California's total bail is about $193 (Caltrans chart). Oregon's presumptive fine for not chaining a commercial vehicle is $880 under ORS 815.140 (ODOT). In Colorado it's up to $500 plus a $79 surcharge, and $1,000 plus a $157 surcharge if you get stuck and block a lane (Colorado State Patrol). Washington lists up to $500 (WSDOT).

That's the same mistake costing anywhere from about $190 to more than $1,100, depending on which side of a state line you made it.

Why this matters more than it looks

Chain laws exist because a spun-out truck can close a mountain interstate for hours. Every state that writes one is trying to prevent that. Nobody's arguing against chain laws.

But a rule only works if drivers can follow it without a law degree. A carrier dispatching a load from Billings to Sacramento has to check a different season, chain count and sign system in nearly every state on the route before the truck leaves the yard. A new driver, or a driver from Texas or Georgia on their first western winter, is the most likely to get it wrong. Those are exactly the drivers the rules are meant to protect.

Colorado State Patrol now runs proactive chain-carry checks on dry days because troopers can't run them during storms (CSP, Oct. 21). We think that's smart enforcement. It also shows that compliance is mostly about knowing the rule before the weather turns. Simpler rules make that easier.

What we're asking for

The western DOTs already work together on freight corridors. They should do it here too:

1. One carry season. Pick a common window, such as Oct. 1 to April 30, for the mountain routes where chains are routinely required. States can still add their own extra routes.
2. One chain-control scale. Three numbered levels with the same meaning everywhere, posted on the sign, not kept as internal shorthand.
3. One truck chain chart. A single page, shared by every participating state, showing how many tires to chain on a tractor-trailer at each level.
4. Comparable fines. States can set their own amounts, but a gap of several hundred dollars for the same violation is hard to justify to a driver.

Until then

Carry a full set plus spares from Oct. 1 to May 31 if you run western mountains. Check each state's live report before the climb: COtrip in Colorado, WSDOT pass reports in Washington, TripCheck in Oregon, QuickMap in California. And keep our state-by-state guide bookmarked, because for now you still need all five rulebooks.