Modern snow and ice tires are so good nowadays that studs aren't needed at all. The only time you might ever require chains is if you're caught in a blizzard with about two feet of heavyfresh snow, otherwise the snows alone will do just fine. It's not a bad idea, since you'll be in Alaska, to keep the chains on hand (stored with the spare tire). In over 30 years of Canadian driving, I've only ever put chains on my car once, and that was to do some towing after a four day snow storm with two wheel drive, otherwise it's overkill.