Chain Controls, and What They Actually Ask of You

Southern California drivers get snow the way tourists get snow — a few days a year, on a road they don't know, in a vehicle set up for a coastal climate. That's a poor combination, and it's the reason the mountain routes into Big Bear, Wrightwood, Idyllwild and over the passes produce so many single-vehicle incidents each winter.

The chain control levels

Caltrans posts chain requirements in three standard levels. The signs are the authority — conditions change hourly — but the framework is consistent:

Note what R-2 actually says: the all-wheel-drive exemption depends on having snow tires on all four corners. All-season tires on an AWD crossover do not automatically meet it. Check the current requirement with Caltrans before you leave, and expect it to change while you're driving.

What all-wheel drive does and doesn't do

All-wheel drive helps you accelerate. It does nothing for braking and very little for cornering — those are tire functions. The most common mountain incident we hear about is a confident AWD driver who got up the hill effortlessly and then discovered that stopping is a separate problem. Tires are the variable that matters; drive type is secondary.

Going up is traction. Coming down is brakes and tires. They are not the same skill and the second one is where people get hurt.

Practical technique

• Slow, smooth, early. Every input gentler than feels necessary.
• Use a low gear on the descent so the engine holds your speed rather than the brakes. This matters as much on snow as it does on a dry grade.
• Look where you want to go, not at what you're trying to avoid. It works.
• If you start to slide, ease off everything and steer gently where you want the front of the car to point. Abrupt correction is what turns a slide into a spin.
• Black ice lives in shade, on bridges, and in the first and last hour of daylight. A wet-looking road at freezing temperature is a suspicious road.

Chains, if you're carrying them

Buy the right size for your tires, and fit them once in your driveway before the trip. Fitting chains for the first time on a dark shoulder in falling snow, in the clothes you brought for a resort, is a genuinely bad experience. Chains go on the drive wheels unless the manufacturer says otherwise, and some vehicles have clearance restrictions that prohibit chains entirely — check the owner's manual, because that's a real constraint on which vehicles can legally proceed at some control levels. Installers at the chain control areas are common; carry cash.

The coverage side, briefly

Sliding off a mountain road is a single-vehicle collision, which means it's your own collision coverage that responds to damage to your car, subject to your deductible — and it isn't there at all on a liability-only policy. Recovery from a ditch or a shoulder in snow is a towing matter, and towing is optional coverage that many policies don't include. Neither of those is a reason not to go; they're a reason to know what you have before you do.

Before the season, send us your policy — we'll tell you in five minutes whether a mountain trip is covered the way you assume it is.