because someone ahead of you will wreck, closing the road anyway. The SP5000s are M&S rated (look on the sidewall) so they count as snow tires. See the link below for more info. They will likely require you to carry chains, even during non-chain conditions, so go out and buy the cheapest ones you can find (they don't need to fit your car) and carry them in the trunk.<ul><li><a href="http://www.dot.ca.gov/hq/roadinfo/wntrdriv.htm">Caltrans</a></li></ul>

CalTrans controls the signs, CHP just enforces the rules. If it's posted "Chains required all vehicles" or "Chains required no exceptions" that means you, too. If you get stopped or get in an accident in those conditions and you don't have chains on, it's a huge ticket. No exceptions for 4wd when it's R-3. It doesn't often happen, but when it does it can happen at a moment's notice.

DMoore
'01 S4