Winter is on its way in the Pacific Northwest! As we head into the winter months, drivers need to make sure they are ready for the difficult driving conditions, particularly on the mountain passes. Washington State trucks need to make sure that they are carrying their chains as of November 1st. That’s next Wednesday.

Chain Requirements by State

To make sure you are prepared, here’s the list of requirements for BC, Washington, Oregon, Idaho, and California:

British Columbia:

While the law in BC states that all commercial vehicles entering the province must carry tire chains from October 1 to March 31st, it applies to all drivers who are travelling outside the temperature climates of the Greater Vancouver and Greater Victoria areas. The government of British Columbia further advises that out of province drivers should carry chains or other traction devices and plan on needing to use them due to rapid changes in elevation and weather. Traveling on BC highways during the winter months is unpredictable!


Chains must be carried Nov. 1 through April 1. It takes five chains to comply with the requirement. However, all vehicles of more than 10,000 pounds gross vehicle weight must carry two extra chains if road conditions require the use of more chains, or if chains in use are broken or otherwise useless. Chains must have two sides attached with cross-sections. Cables can be permitted. Plastic chains are prohibited.


OR law applies to ALL highways in the state. Signs advise when you are required to carry chains and when you are required to use them. You will need to have six chains on hand to comply in Oregon.


Officials in ID can determine, at any time, that Lookout Pass on I-90, Fourth of July Pass on I-90 or Lolo Pass on Highway 12 are unsafe. When this occurs, signs will alert you to chain up.


CA does not require trucks to carry chains during any specified time. When the weather hits, it takes at least eight chains for a standard tractor-trailer configuration to comply with the regulations. Conventional tire chains and cable chains, as well as other less conventional devices such as “Spikes Spiders,” are permitted. Trucks with cable-type chains are legal, but may be restricted at times if severe conditions occur; this happens frequently in the higher elevations such as Donner Pass. Automatic chaining systems are permitted in the state; however, you may still be required to add additional “traditional” chains to fully comply with the placement requirements.

Need a refresher on chaining up your vehicle? Check out our video on Chain Training, produced at TC Trans. The video covers: key tools to use while chaining up, how to chain up without having to move your truck, and how to make sure you are legal for the specifications of BC, Washington, Oregon, Idaho, and California for truck and trailer:

Checklist to Prepare for Winter Driving

While keeping these chain laws in mind, drivers also need to start thinking about preparing their equipment for the winter months. Trucks, by design are tough machines; but still, contain many parts and systems to function, many of which are sensitive to the external factors presented in cold weather. Here’s the top 4 areas drivers need check to be ready:

1) Coolants

The first line of defense against cold weather. Conventional and extended-drain coolants are both widely used in trucking.

  • Check the coolant system for leaks, including all clamps and hoses. Make sure the coolant level is that the “full” mark. If not, pressurize the system to track down any coolant leaks.
  • Use a high-quality coolant and additives from trusted suppliers. Do no rely on questionable marketing claims and unknown sources of engine coolant that can provide marginal protection or create problems with newer heavy-duty vehicles.
  • Pull a coolant sample and check the solution to see if the freeze point is appropriate; a 50-50 solution will protect your engine down to -34F. This can be measured many ways, including a handheld refractometer, test strip, or hydrometer. The refractometer is considered the most accurate.
  • Eyeball a sample of the solution in a see-through container; it should be clear, bright, and free of debris.

2) Oil

Using the correct oil viscosity for where your truck operates is key.

  • When determining cold weather viscosity, note that cold weather oil performance is predicted on ambient air temperatures; engines are not affected by wind-chill values. Check with your engine manufacturer or oil supplier for cold-weather recommendations
  • In extreme climates, switch to a lower-viscosity oil that will flow better.
  • Don’t use cold-weather additives for engine oil; manufacturers blend engine oils for cold-weather performance.

3) Battery Systems

Batteries can be the first to fail in icy wind conditions. In cold weather, more demand is placed on batteries because the cold causes a resistance to charge; this action ultimately decreases the batteries sulfation level and reduces life.

  • Ensure you have the correct battery for your vehicles specifications and its demands. A vehicle may require an AGM (amalgamated glass mat) or a conventional (lead-acid flooded cell) battery depending on these factors.
  • All batteries come in starting, dual-purpose or deep-cycle options, so make sure you choose the correct battery for your needs.
  • Battery age is crucial in cold weather; if the batteries are 3 years old and winter is coming, consider an early replacement.
  • To ensure proper battery performance, test them frequently and keep them charged prior to and during winter months.
  • Use a charger with an AGM setting when charging an AGM externally.
  • Winter battery preparations are altered dramatically if your truck uses an auxiliary power unit (APU). APU-tethered batteries often are discharged at a lower rate which can allow them to be susceptible to damage from freezing.
  • A battery’s recharge efficiency is reduced in cold weather, which strains the battery even more. Attempting to warm a cab with a battery that is not fully charged may lead to starting issues in the morning.

4) Tires

The important thing to remember here is that conditions for winter traveling can be more challenging. Safety should be the number one priority. Pre-trip inspections should always be performed.

  • Maintain proper tire pressure – tire pressure will drop in cold weather, so set the tire pressure prior to the trip while the tires are at ambient temperature. Use a properly calibrated gauge to check pressure.
  • Monitor tread depths – if you live in severe winter regions, consider a tire tread designed for those conditions.
  • Watch for irregular wear which may be signify weather related low traction conditions.

Use these tips to make sure you will be ready for winter on the roads. Also, be sure to check the state’s Department of Transportation websites, which report on weather conditions in the passes from November 1 to April 1. Here’s a list of our most checked State DOT sites:

  • Washington DOT Mountain Passes – click on the pass you will be travelling through for more detail and conditions.
  • Oregon TripCheck – click on the “Quick Links” section, and it will relocate the map to the specific region you want to check. Once you are in the region, you can use the map to see the traffic cameras and conditions. We typically look at the East region of the state.
  • Idaho DOT Highways with Mountain Passes – click on the highway you are travelling on to get information on all mountain passes the highway travels through.
  • California DOT Mountain Highways – click on the mountain highways you want detail on and it will take you to the text conditions for that area.
Are You Ready for Winter Driving? The Chain Requirements and Winter Driving Checklist Drivers Need to Know was last modified: by