Restrictions on the Siskiyou Pass
ODOT and Oregon State Police maintain check points on either side of the Siskiyou Pass and will turn motorists around if they aren’t prepared. The basic carry chains requirement and three additional types of restrictions are used.
When signs say you must carry chains, the chains must be in or on your vehicle all winter, and must be the right size and of sufficient number to comply with chain laws.
Single axle trucks and vehicles pulling trailers
Under this restriction, all single axle trucks over 10,000 GVW (gross vehicle weight), trucks pulling double trailers, and any vehicle pulling a trailer is required to install chains. Traction tires cannot be substituted for chains.
All trucks and vehicles pulling trailers
Under this restriction, all trucks over 10,000 GVW (as well as any vehicle pulling a trailer) need to chain up. Traction tires cannot be substituted for chains.
Full chain restriction
This is the most severe winter restriction used in Oregon (short of a full closure).
Under the full chain restriction all vehicles with the exception of 4-wheel drive and emergency response vehicles are required to install chains. A traction tire is not allowed to substitute for chains.