Below you will find the most common questions on tire and chain requirements for Washington’s state highways. The Washington State Department of Transportation follows WAC Title 204, chapters 22 (Standards for tire chains) and 24 (Traction devices) as it relates to tire and chain requirements.
You can access mountain pass information, including road restrictions, avalanche control warnings and more information on traffic and travel at http://www.wsdot.wa.gov/traffic/.
What is the difference between four-wheel drive and all-wheel drive?
As it relates to meeting traction requirements, there is no difference between four-wheel drive and all-wheel drive. They are the same.
What is the definition of a traction tire?
An approved traction tire, whether on a four-wheel/all-wheel drive vehicle or a standard vehicle, must have at least an eighth of an inch of tread and be labeled M&S, All Season, or have a Mountain/Snowflake symbol. These tires can be used year round. When you install approved chains, any tire becomes a traction tire. For more information on your specific vehicle and its traction tire options, contact your local tire dealer.
When is it legal to use studded tires in Washington?
Washington allows studded tires from November 1 through March 31. While sometimes providing additional traction on snow and ice, studded tires damage roadways.
Are there any exceptions/extensions to the studded tire season?
There is no individual exception to the studded tire season. The department will review the weather forecast and may extend the March 31 deadline and issue a press release. This information will also be available on the WSDOT website at http://www.wsdot.wa.gov/traffic/.
I have studded tires and occasionally drive through the passes. Since I have studded tires, do I also need chains when chains are required?
When chains are required, studded tires alone will not meet the chain requirement unless your vehicle is a four-wheel/all-wheel drive vehicle. Please remember, under extreme weather circumstances, the Washington State Patrol (WSP) can mandate that all vehicles chain up, including studded tire vehicles and four-wheel/all-wheel drive vehicles. WSDOT posts signs to keep motorists informed of chain requirements.
Do I need to carry chains when traveling through the pass?
Passenger vehicles are not required to carry tire chains but WSDOT recommends all drivers carry chains. Should weather/road conditions worsen, WSP and WSDOT may require chains on all vehicles. If this restriction is in effect, all vehicles without them will be turned back or cited by the WSP. Commercial vehicles over 10,000 pounds gross vehicle weight rating (GVWR) are required to carry chains on most mountain passes in Washington State. For more information on the chain requirements for commercial vehicles, visit: www.wsdot.wa.gov/commercialvehicle/chain_req.htm.
Can you explain “Chains Required”?
When WSDOT posts “Chains Required” on its highway information signs, it is unlawful for any vehicle to enter the controlled area without having chains on its drive tires. There is an exemption for four-wheel/all-wheel drive vehicles, provided tire chains are available for at least one set of drive tires. When WSDOT removes the Chains Required post, you are able to remove your tire chains. If you do need to put on or take off tire chains, first leave highway travel lanes.
I have a four-wheel/all-wheel drive vehicle. Do I have to install chains when signs indicate that chains are required?
As long as your vehicle is equipped with traction tires, chain installation is generally not required on four-wheel/all-wheel drive vehicles. Under extreme weather conditions, the Washington State Patrol (WSP) can mandate that all vehicles chain up, including four-wheel/all-wheel drive vehicles. WSDOT posts signs to keep motorists informed of chain requirements.
Do I have to put chains on all four tires when chains are required?
On a front-wheel drive vehicle, you must install chains on the front two tires. On a rear-wheel drive vehicle, you must install chains on the rear two tires. Chain installation is generally not required on four-wheel/all-wheel drive vehicles. Under extreme weather conditions, the Washington State Patrol (WSP) can mandate that all vehicles chain up, including four-wheel/all-wheel drive vehicles. Should the WSP make this determination, chains must be installed on one set of drive tires of the four-wheel/all-wheel drive vehicle.
My vehicle cannot accommodate tire chains. How can I comply with chain requirements?
When chains are required, you can either choose to drive a different vehicle that can accommodate tire chains or wait until WSDOT removes the chain requirement. The WSP could cite or turn back any vehicles in noncompliance.
How do I find out about when WSDOT plans Avalanche Control?
The best way to find out about WSDOT mountain pass reports is to visit www.wsdot.wa.gov/traffic/passes/camera.aspx. You can learn more about the WSDOT Avalanche Control Team here: www.wsdot.wa.gov/maintenance/avalanche/. We are also working on a typical “play by play” explanation on how they do avalanche control on Snoqualmie Pass and Stevens Pass.
What are the chain requirements on non-commercial vehicles towing a trailer such as an RV, horse trailer, etc.?
When a vehicle is towing a trailer and the combined weight of the vehicle and trailer exceeds 10,000 pounds, the commercial vehicle requirements apply. Visit www.wsdot.wa.gov/commercialvehicle/chain_req.htm for more information.
I drive a commercial vehicle. How do I know which tires to chain when chains are required?
To view a diagram, visit: www.wsdot.wa.gov/commercialvehicle/diagram.htm
Vehicles over 10,000 pounds must carry a minimum of two extra chains in case road conditions worsen. You can also read the complete text of WAC 204-24-050 at http://apps.leg.wa.gov/WAC/default.aspx?cite=204-24-050.
What is considered an oversized vehicle?
A vehicle is considered oversized if it has a gross weight rating (GVWR) over 10,000 lbs. and the vehicle exceeds the legal weight for that vehicle. Vehicles exceeding 8' 6" in width, 14' in height and/or exceeding 40' in length for a single vehicle. Also considered oversize are, semi trailers in excess of 53 ft. and double trailers in excess of 61 ft. When exceeding these limits, permitting is required to travel in Washington State. Some permitted vehicles may travel when traction/chains are required. Contact WSDOT Commercial Vehicles Office at (360) 704-6340 to determine if permitting is required and which vehicles are exempted.
How do I get more information?
For more information, contact WSDOT Winter Maintenance at WSDOTWinterOperations@wsdot.wa.gov