You can use car chains when you are driving in winter conditions where snow or ice is present on the road, and typically only when required by law or recommended by authorities. The most common places are on mountain passes, in national parks during winter, and on certain highways that traverse snowy regions. The primary rule is to use chains on driven wheels to maximize traction.
Legally, chain requirements are often indicated by roadside signs. You'll see signs like "Chains Required" or "R2 Conditions," which mean chains or approved traction devices are mandatory for most vehicles. It's illegal to ignore these active signs. You should install chains before you reach the steep, icy section of the road, usually in a designated chain installation area.
Practically, chains are for low-speed driving in severe conditions. They are not meant for dry or wet pavement. Driving on bare roads with chains can damage both your tires and the road surface. Once you clear the hazardous section and the road is clear, you must remove them.
| Chain Control Level | Requirement | Typical Scenario |
|---|
| R1 | Chains required on vehicles without 4WD/AWD and snow tires. | Roads are snow-covered, but passable with caution. |
| R2 | Chains required on all vehicles except 4WD/AWD with snow tires. | Conditions are more severe; most cars need chains. |
| R3 | Chains required on all vehicles without exception. | Extreme conditions; roads may be closed to all traffic. |
| Conditional | Carry chains in vehicle from November to March. | Common in mountain areas like the Sierra Nevada. |
The key is to check weather forecasts and Department of Transportation (DOT) alerts for your route. If there's a chance of snow, carrying chains is a smart precaution, even if you have an all-wheel-drive vehicle, as conditions can change rapidly and mandates can be enforced unexpectedly.
