WSDOT’s snowplows are ready. The question for drivers is whether their tires, chains, and habits are ready too. In an Oct. 22 release, the Washington State Department of Transportation laid out this winter’s studded-tire window, traction options, and why one spinout can shut down a mountain pass.
Studded Tires: Nov. 1 Through March 31
By law, studded tires are legal in Washington only from Nov. 1 through March 31. That applies to every vehicle in the state, including out-of-state traffic. There are no personal exemptions.
Important limits from WSDOT:
- Studded tires do not count as chains when chains are required. You still need to install chains over studded tires in posted chain areas.
- WSDOT estimates studded tires cause tens of millions of dollars in pavement damage to state roadways each year.
- Stud-free winter tread tires with the mountain-and-snowflake symbol and at least 1/8 inch of tread are legal year-round and are a different product from ordinary all-season tires.
Chains and Traction Requirements
WSDOT asks drivers who travel over the mountains or in winter weather to carry tire chains and practice installing them at home before storms hit. Conditions can change quickly, and chains may suddenly be required.
- Drivers who fail to install chains when required risk a fine enforced by the Washington State Patrol.
- Any tire becomes a traction tire when chains are installed.
- WSP publishes a list of approved traction-tire alternatives that can be used when chains are required.
- Even if a vehicle maker advises against chains on a particular model, that does not excuse travelers from state law when chains are required.
WSDOT also permits businesses to install and remove motorist-owned chains at signed locations when chains are required, but crews are not always there. Plan to install your own.
One Spinout Can Stop Everyone
Mountain pass closures happen every winter for spinouts, crashes, impaired drivers, and avalanche control. WSDOT notes that a single spinout can close an entire pass. A major crash can take even longer when specialized tow equipment or fuel cleanup is needed.
Drivers can help by:
- Slowing down for conditions
- Leaving plenty of space between vehicles
- Avoiding distractions
- Postponing nonessential trips during major storms
Statewide, WSDOT fields hundreds of snowplows and asks the public to slow down and be patient around them. Plows work at lower speeds to treat the road and may cover dozens of miles in a shift.
Know Before You Go
WSDOT recommends:
- Check winter driving tips and current traction and chain requirements for mountain passes.
- Use the WSDOT app and real-time travel map for conditions.
- Assess tire tread before storms arrive.
- Carry chains and the tools to put them on.
- Watch for people walking or biking in winter weather. About a third of Washington residents don’t drive, WSDOT notes, so winter safety is for everyone.
Practice Chains Before You Need Them
The first time you install chains should not be on a dark shoulder in freezing rain. At home:
- Confirm the chains fit your tires.
- Practice laying them out and fastening them with gloves on.
- Keep gloves, a flashlight, and a kneepad in the vehicle with the chains.
When a pass sign flips to chains required, that practice is what keeps you and the line of cars behind you moving.
Washington Traffic Level 1 Course
Winter tickets happen when people rush, follow too closely, or ignore posted restrictions. If your court offers a traffic safety course for dismissal, Defensive Drivers Institute’s Washington Traffic Level 1 Course is accepted by most Washington courts that offer one; your court may need you to confirm. Completing it can keep the violation off your driving record. The course is 100% online, you can start and stop anytime, and you can download your certificate as soon as you finish. Check your court’s requirements before you enroll.
For more on sharing Washington roads with roadside workers and patrols, see our post on the move-over law and impaired driving.
The Bottom Line
Studded season is open, but studs aren’t a substitute for chains when chains are required. Check pass conditions, carry chains you know how to install, and slow down so one spinout doesn’t close the mountain for everyone.
Got a Washington traffic ticket? Confirm your court allows it, then start the Washington Traffic Level 1 Course.
