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If you are heading to a snowy destination, there is a big chance you will encounter some sort of road restriction put out by the local Department of Transportation. This is especially true if your travel occurs during a storm.

Here we explain what these restrictions are so that you are informed and can make safe decisions about your travel plans.

Road restrictions are put in place to address dangerous road conditions due to inclement weather. These restrictions are usually temporary from a few hours to a day for most major highways but can also stretch longer for a multi-day storm or on rural, mountainous roads.

A travel restriction means that certain traction is required for your vehicle in order to drive on that specific road.

These restrictions are alerted via different state transportation websites, AM or local radio stations and by large digital signs on the side of the road. A good way to find this information online ahead of your trip is to just search for “travel restrictions” and the state or area you are heading into.

In California, if you go to the CalTrans site you can actually enter in your highway number to check.

Keep in mind, conditions change quickly especially if a weather system is moving through. It is a good idea to check a couple of sites to cross reference information that may not have been updated in real time.

We’ve found that in the Tahoe Region, https://nvroads.com/ has been the best site for up to date conditions.

Each state has a different type of alert model and chain laws for passenger and commercial vehicles. For example, California uses a code, calling them level R1 through R3. Washington State does not coding but descriptive requirements such as “Traction Tires Advised”. Colorado calls them simply Laws. (They are all “laws” in every state though, naming convention aside.)

What are you driving?

It is important to know the basic type of vehicle you will be driving when it comes to transmission style. This describes how power is directed to the wheels of your vehicle. You might already know this about your own vehicle but what about your rental? You should know this about your vehicle before venturing into any snowy, winter area as traction laws apply to the type of vehicle and tires you have.

The options are two wheel drive (2WD), four wheel drive (4WD) or all wheel drive (AWD).

2WD - Power is directed to only two of the four wheels. Usually this is either the front two wheels or back two wheels.

4WD or 4x4 - Power is directed to all four wheels simultaneously. This can be a full-time feature or something that has to be engaged with a special gear shift. Modern technology has improved this option and the line can often blur as to what distinguishes this type from an all wheel drive vehicle.

AWD - Similar to 4WD, power is directed to all four wheel simultaneously. These cars can either operate like 2WD and go all wheel as traction demands but it depends on the manufacturer. These types of vehicles do not have the option to demand 4WD by way of a special shift.

Carry chains made for your specific vehicle model.

If you plan to frequently travel to the mountains, it makes sense to purchase a pair of snow chains for your vehicle. Even if you have a four wheel drive with mud tires, you could run the risk of being turned around if a chain restriction is in place for ALL vehicles.

Chains come in different sizes and materials. You will need to know your make and model to shop for the right fit. Some performance or luxury cars require a specific type so make sure you also check the information book that came with your vehicle to make sure. You don’t want to damage your vehicle or tires or even void your warranty by using the wrong chains.

You will also want to have a good idea on how to apply the chains to your vehicle in advance. Trust us, you don’t want to be outside fiddling around in a freezing ice storm trying to figure out how they go on. (And don’t put them on backwards either! Follow the manufacturer’s directions.)

If you are driving a rental, you can usually request chains to be provided for an additional charge.

Below we have a few of the state requirements for traction pulled from their transportation authority’s website.

This information is really easy to find online. Make sure to check in with your local Department of Transportation websites for up to date information and transportation laws.

California Chain Requirements

R1: Chains are required - snow tread tires allowed.

R2: Chains are required on all vehicles except four wheel drive vehicles with snow tires on all four wheels.

R3: Chains are required - all vehicles - no exceptions.

Source: CalTrans http://www.dot.ca.gov/hq/roadinfo/wo.htm

Washington State Traction Advisories

Traction tires advised - oversize loads prohibited. Oversize vehicles may be restricted from roadways during severe weather conditions.

Traction tires required - Passenger vehicles must use approved traction tires. Chains are required on all vehicles over 10,000 gross vehicle weight rating (GVWR), including large passenger trucks and SUV's over 10,000 GVWR.

Tire chains required - except four-wheel/all-wheel drive* (as long as one set of chains is carried inside 4WD/AWD vehicle). *If the vehicle or vehicle and load are more than 10,000 pounds the 4WD/ADW exemption does not apply.

Source: https://www.wsdot.com/winter/traction.htm

Colorado Chain Law

Traction Law (Code 15)

During an active Traction Law (also known as a Code 15), motorists must have either snow tires, tires with the mud/snow (M+S) designation, or a four-wheel/all-wheel drive vehicle. All tires must have a minimum one-eighth inch tread. You can also install chains or an alternative traction device (like AutoSock) to be in compliance with the law if your tires aren't adequate.

Passenger Vehicle Chain Law (Code 16)

During severe winter storms, CDOT will implement a Passenger Vehicle Chain Law (also known as a Code 16). This is the final safety measure before the highway is closed.

When the Passenger Vehicle Chain Law is in effect, every vehicle on the roadway must have chains or an alternative traction device (like AutoSock).

Source: https://www.codot.gov/travel/winter-driving/Tract...