[John E Davies]

In Washington, if the chains required is posted you can four wheel it but you have to have chains in the car.

With AWD and good snow tires, not All-seasons, you should never actually need to install the chains, though as summerwind noted, AWD is exempt here in Washington State, but you do have to bring some along "just in case". Usually before the ultimate "All vehicles must install chains" situation develops, the State Patrol shuts down the highway.

I always carry chains or cables in all my vehicles - I have never been actually forced to install them other than to negotiate super-deep snow drifts on small some side road.

John Davies
Spokane WA