Chain Laws

Montana's chain provision has no season attached. The one date range in the statute governs studded tires, not chains, and the two are regularly confused.

California sets chain requirements by vehicle configuration rather than by a single weight threshold, and one combination can be banned from a chain control area outright.

An Oregon chain sign is not a single instruction. It selects one of four escalating requirements, and only the top two compel a heavy vehicle to fit chains.

Colorado sets a higher weight threshold than its neighbours and applies the rule across the whole State Highway System. It also reaches vehicles that are not commercial at all.

Wyoming sets an ordinary fine for ignoring a travel restriction and a much larger one where the violation shuts the highway. The second figure is the one that shapes behaviour.

Utah does not run a single statewide chain rule. It designates segments by class, and the class decides whether the requirement reaches only heavy vehicles or every vehicle on the road.

Nevada's rule turns on a single weight line. At or below 10,000 lb you may choose among traction devices, chains or snow tires. Above it, the regulation says chains.

Idaho can require chains on Lookout Pass, Fourth of July Pass and Lolo Pass. Everywhere else in the state chains are permitted but never compulsory.

Every other chain law waits for a sign. Washington also requires vehicles over 10,000 lb to carry chains on twelve named routes from 1 November to 1 April, whether or not chains are required that day.

The same sentence appears in states that mandate chains and states that never have. Reading it as a requirement is the single most common error in published chain-law tables.

Nine states can compel a commercial vehicle to run chains. Most of the rest only permit them. Here is the difference, and why the two are constantly confused.