Washington Tire Chain Laws

How Washington handles chains

$500 flat, including all statutory assessments (RCW 47.36.250). Vehicles over 10,000 lbs must mount chains when WSDOT posts the requirement on any part of the public highway system. They must carry at least two extra chains with no season in the rule, and enough chains from November 1 to April 1 on 12 listed routes (WAC 204-24-050). Approved traction tires do not substitute for a heavy truck. Chains must be metal or cable, not plastic. Watch I-90 Snoqualmie, US-2 Stevens Pass, and SR-410 Chinook Pass. Check WSDOT mountain pass reports for the live requirement.

When, where, and what counts

• When required: You mount chains only when WSDOT posts a chains-required sign. WSDOT can set the requirement at any time for any part of the public highway system, so posting is not limited to pass approaches (RCW 47.36.250). November 1 to April 1 is the season for carrying chains on 12 listed routes. It is not a season for mounting them (WAC 204-24-050).
• Where: Any part of the public highway system when WSDOT posts it (RCW 47.36.250), including the mountain passes: I-90 Snoqualmie, I-82, SR-97, US-2 Stevens Pass, SR-410 Chinook Pass, US-12 White Pass, and other posted routes. From November 1 to April 1, vehicles over 10,000 lbs GVWR must carry chains on 12 routes (WAC 204-24-050): I-90 North Bend MP 32 to Ellensburg MP 101; SR-97 MP 145 to the US-2 junction; US-2 Index MP 36 to Dryden MP 108; US-12 Packwood MP 135 to Naches MP 187; SR-97 Columbia River MP 0 to Toppenish MP 59; SR-410 Enumclaw to Naches; SR-20 Tonasket MP 262 to Kettle Falls MP 342 and Newhalem MP 120 to Winthrop MP 192; SR-155 Omak MP 79 to Nespelem MP 45; SR-970 MP 0 to 10; SR-14 Gibbons Creek MP 18 to MP 108.40; SR-542 MP 22.91 to 57.26; I-82 Ellensburg Exit 3 to Selah Exit 26.
• Applies to: Vehicles over 10,000 lbs GVWR must mount chains when signs require. They must carry at least two extra chains, and the rule text sets no season or route limit (WAC 204-24-050). On the 12 listed routes they must also carry enough chains from November 1 to April 1, and at other times when chains are required. Local delivery vehicles shown on bills of lading are exempt from that if they stay outside the chain area and do not cross the pass. WSDOT posts three sign levels, and each one starts with "Traction advisory, oversize vehicles prohibited." The second adds chains required for vehicles over 10,000 lbs GVW. The third adds chains required for all vehicles except all wheel drive. Ordinary trucks over 10,000 lbs chain up at the second and third levels. WSDOT prohibits oversize permit moves on mountain passes while any of these signs is displayed. WSDOT or the State Patrol can also bar any vehicle from a chain control area if it would have difficulty traveling it safely.
• Chains vs traction devices: Chains must be metal or cable, not plastic. When required for a heavy vehicle, approved traction tires do not substitute; chains or an approved alternative traction device must be mounted. A tire counts as chained if it has an approved tire chain or a device the Washington State Patrol lists as approved for that vehicle combination, used the way the manufacturer recommends (WAC 204-24-050; WAC 204-24-040). The State Patrol approves chains and traction devices, and its cable chain standards include a heavy truck class (WAC 204-24-020). If you run automatic chains, you must also carry regular chains for the outside drive tires on every axle that has automatic chains. On the State Patrol list for vehicles over 10,000 lbs, AutoSock is approved for 5 or fewer axles and for 5 or more. EasySox, ISSE Safety and SuperSox HD100 are approved for 5 or fewer axles only. Alpha Trax, Easy Grip EVO, Grip Tex, NorSoxx N37/N41, Polaire Grip, Polaire Steel and SOS Grip are not approved for heavy vehicles. Where chains go when chains required is posted: with 2 to 4 axles, one tire on each side of the drive axle, or of one drive axle if tandem, plus one tire on the last axle of the last trailer, or either of the last two if tandem. Auto transporters chain one tire on each side of each drive axle plus one trailer tire. A 5-axle tractor with tandem drives and a tandem semi chains all tires on one drive axle or one tire on each side of each drive axle, at least four drive tires, plus one tire on either of the last two trailer axles. Other 5-axle combinations chain all tires on the single drive axle, or on one drive axle if tandem, plus one tire on the last axle of the last trailer. With 6 or more axles, chain all tires on the single drive axle or on one of the dual drive axles, plus one trailer tire on either of the last two axles. The rule also calls for one tire on each side of the other drive axle, and WSDOT's guidance diagram ties that to the all vehicles chains required level. The same diagram says tractors on super-single tires chain each tire on each drive axle.
• Check the live order: WSDOT mountain pass reports (wsdot.com/travel/real-time/mountainpasses), the WSDOT App, or WSDOT's Bluesky account @passes.wsdot.wa.gov for the requirement in effect right now.
• Fine: $500 flat, including all statutory assessments (RCW 47.36.250).

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