Winter Driving Tips

Preparation is Key for Winter Driving Conditions.

Caltrans is encouraging motorists traveling to or through the mountains this winter to be prepared for winter driving conditions. Learn more in these updated tips to help drivers keep safe:

Mountain Pass Closures

Before driving, check with the Caltrans Highway Information Network (CHIN) 800.427.7623

Mountain Pass Route 2019/2020  2020/2021  2021/2022  2022/2023 2023/2024 
Ebbetts Pass SR 4 12/2 - 5/15 12/15 - 5/12 12/16 - 5/12 11/18 - 6/8 1/2 - 5/9
Monitor Pass SR 89 12/2 - 5/8 12/16 - 4/9 12/16 - 4/1 12/8 - 5/12 1/2 - 4/10
Lassen Loop SR 89 11/29 - 5/22 11/10 - 5/17 10/28 - 6/3 11/15 - 7/3
11/27 -
Sonora Pass SR 108 12/2 - 5/15 12/15 - 5/6 12/16 - 5/12 11/18 - 6/9 1/2 - 5/16
Tioga Pass SR 120 11/27 - 6/15 11/25 - 5/27 12/16 - 5/27
11/17 - 7/22
11/21 - 6/10
June Lake Loop SR 158 11/26 - 2/26 12/15 - 3/26
12/16 - 3/21
12/12 - 4/27  2/1 - 4/9
Mammoth Lakes SR 203 11/4 - 5/28 11/6 - 6/2 10/22 - 6/17 11/4 - 7/14
11/9 - 6/7
Lake Sabrina to Aspendell SR 168 11/26 - 5/1 11/18 - 4/15 12/16 - 4/26
11/16 - 6/1 11/15 - 4/18
Historical Mountain Pass Closure Dates (PDF)

Before Heading for Snow Country

Winter driving on roads and highways in the snowcapped mountains of California can be a pleasant adventure or it can be frustrating, tiring and sometimes even hazardous. Caltrans provides the following information to help make your mountain driving safe and pleasant.

  • Make sure your brakes, windshield wipers, defroster, heater and exhaust system are in top condition.
  • Check your antifreeze and be ready for colder temperatures.
  • You may need to add concentrated windshield washer fluid to the windshield washer fluid reservoir to prevent an icy windshield. More information about this type of windshield washer fluid can be found on the California Air Resources Board web site.
  • Check your tires. Make sure they are properly inflated and the tread is in good condition. Always carry chains. Make sure they are the proper size for your tires and are in working order. You might want to take along a flashlight and chain repair links. Chains must be installed on the drive wheels. Make sure you know if your vehicle is front or rear wheel drive.
  • Other suggested items to carry in your car are an ice scraper or commercial de-icer, a broom for brushing snow off your car, a shovel to free you car if it is "snowed in", sand or burlap for traction if your wheels should become mired in snow and an old towel to clean your hands.
  • It is also a good idea to take along water, food, warm blankets and extra clothing. A lengthy delay will make you glad you have them.
  • Weather conditions may warrant detouring traffic from the main roadway. It is strongly suggested that drivers always keep an updated map containing the areas of travel.
  • If you have a cellular telephone, pre-load the Caltrans Highway Information Network (CHIN) phone number: (800) 427-7623 for convenient, updated road conditions.
  • Put an extra car key in your pocket. A number of motorists have locked themselves out of their cars when putting on chains and at ski areas.

Driving Tips

  • Allow enough time. Trips to the mountains can take longer during winter than other times of the year, especially if you encounter storm conditions or icy roads. Get an early start and allow plenty of time to reach your destination.
  • Keep your gas tank full. It may be necessary to change routes or turn back during a bad storm or you may be caught in a traffic delay.
  • Keep windshield and windows clear. You may want to stop at a safe turnout to use a snow brush or scraper. Use the car defroster and a clean cloth to keep the windows free of fog.
  • Slow down. A highway speed of 65 miles per hour may be safe in dry weather, but an invitation for trouble on snow and ice. Snow and ice make stopping distances much longer, so keep your seat belt buckled and leave more distance between your vehicle and the vehicle ahead. Bridge decks and shady spots can be icy when other areas are not. Remember to avoid sudden stops and quick direction changes.
  • Be more observant. Visibility is often limited in winter by weather conditions. Slow down and watch for other vehicles that have flashing lights, visibility may be so restricted during a storm that it is difficult to see the slow moving equipment.
  • When stalled, stay with your vehicle and try to conserve fuel while maintaining warmth. Be alert to any possible exhaust or monoxide problems.
  • Give snowplows room to work. A "strike team" may include several plow trucks, including Tow Plows and wing plows using multiple lanes on a major highway. Stay at least four (4) car lengths back from snowplows and snow removal equipment.
  • Salt brine trucks as well as sand and cinder spreading trucks have signs saying "Stay Back". This is for your safety since material can be spread/sprayed across multiple lanes.
  • Equipment operators must focus on snow removal and cannot always watch out for motorists. Refrain from, or use extreme caution, when passing snow removal equipment.

Chain Controls

During the winter months, motorists may encounter traction chain controls in the mountain areas within California. When chain controls are established, signs will be posted along the road indicating the type of requirement.

  • You must stop and put on chains when highway signs indicate chains are required. You can be cited by the California Highway Patrol and fined if you don't. You will usually have about a mile between "Chains Required" signs and the checkpoint to install your chains.
  • Control areas can change rapidly from place to place because of changing weather and road conditions.
  • The speed limit when chains are required is 25 or 30 miles an hour.
  • When you put on chains, wait until you can pull completely off the roadway to the right. Do not stop in a traffic lane where you will endanger yourself and block traffic.
  • Chain Installers: If you use the services of a chain installer, be sure to get a receipt and jot the installer's badge number on it. Remember, chain installers are independent business people, not Caltrans employees. Having the badge number may help with any misunderstandings later. Chain installers are NOT allowed to sell or rent chains.
  • When removing chains, drive beyond the signs reading "End of Chain Control" to a pull-off area where you can safely remove them.

For more detailed information on chain controls and chain installation, see our Chain Controls / Chain Installation page.

Truckers: see our Truck Chain Requirements page.

Caltrans Highway Information Network (CHIN)

Caltrans officials urge you to check road conditions often. To help keep abreast of changing conditions, Caltrans operates the Caltrans Highway Information Network which motorists may telephone (800) 427-7623 for up-to-the-minute information in California and Western Nevada (Lake Tahoe/Reno Area). The network is updated as conditions change, and is voice-activated for safety and convenience.

Caltrans QuickMap

See Caltrans QuickMap for a real-time, zoom-able California map of current traffic conditions including lane closures, CHP incidents, changeable message signs, chain controls, video cameras and more.