What “Chains Required” Actually Means in Washington

If you’ve ever checked a mountain pass report and seen a chain advisory pop up, you’re not alone in wondering what “chains required” really means.

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In Washington, those alerts aren’t suggestions, but are legal requirements tied to dangerous weather and road conditions.

WSDOT Explains Traction Tires Advised vs. Required

When “Traction Tires Advised” is posted, conditions are slippery, but chains are not mandatory yet. Oversized loads are restricted, and drivers are strongly encouraged to slow down and be prepared.

Once WSDOT changes advisories to “Traction Tires Required,” things get more serious. All passenger vehicles must have approved traction tires, and that means you have to use tires labeled M+S, All Season, or showing the mountain/snowflake symbol with at least 1/8-inch tread. Vehicles over 10,000 pounds, including large trucks, SUVs, and RVs, must install chains at this stage.

When Chains Are Required

“Tire Chains Required” means most vehicles must chain up. Four-wheel drive and all-wheel drive vehicles can continue without chains, but they must still carry them or face a citation. Studded tires do not count as chains. They also need to be the correct size for your vehicle.

During extreme conditions, WSDOT may post “Chains Required on All Vehicles.” That means exactly what it sounds like: every vehicle, including AWD and 4WD, must install chains with no exceptions.

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Chain requirements are not about convenience, but are about safety and keeping mountain passes open. Slide-outs from unprepared vehicles are one of the biggest reasons roads shut down. Ignoring chain-up notices can result in a $500 fine and put others at risk. If you are attempting to cross any of Washington State's snowy mountain passes, make sure you are prepared, or you will have to pay.