Does FMCSA require commercial trucks to carry tire chains nationwide?

No. The Federal Motor Carrier Safety Administration (FMCSA) does not establish a universal nationwide tire-chain carry calendar or equipment mandate. Instead, 49 CFR § 392.2 mandates that every commercial motor vehicle must comply with the operating laws of the state or jurisdiction in which it operates, while 49 CFR § 392.14 requires extreme caution and stopping if hazardous conditions become too dangerous. Violations of state or local operating laws may be recorded under § 392.2 when cited during a qualifying roadside commercial vehicle inspection.

Which states have mandatory seasonal commercial chain carry laws?

Among the states reviewed, Colorado, Montana, and Washington have explicit fixed seasonal commercial-chain carry requirements in the official sources reviewed. Colorado requires CMVs >=16,001 lbs to carry chains across seven mountain corridors between September 1 and May 31. Washington mandates carrying chains plus two spares on vehicles >10,000 lbs on 12 designated route entries (13 normalized segments) between November 1 and April 1. Montana requires towing units >=26,001 lbs to carry chains between October 1 and April 30.

How many tire chains does a standard 5-axle semi truck need?

Chain counts depend strictly on state statute and vehicle configuration. In Washington, a 5-axle tandem-drive tractor-semitrailer must chain four drive tires (all four on one drive axle or outer tires on both) plus one trailer drag tire, and must carry at least two extra chains in reserve (minimum 7 devices on board). In Colorado under Level 2 controls, four drive tires must be chained. In Oregon, tandem tractors towing semitrailers must chain four drive tires plus two tires on any semitrailer axle.

Which truck axles need tire chains on commercial vehicles?

Required axle placement depends on state regulations, active control levels, and vehicle configuration. Most commercial chain rules focus placement on powered drive axles and, in select states, designated trailer braking axles. Steer axles are not subject to a universal national rule; drivers must consult specific state controls, configuration rules, and manufacturer clearance guidance. Wide-base single tire ("super single") requirements also vary by state statute.

Do commercial trailers need tire chains ("drag chains")?

Trailer drag chains are required in select Western states depending on vehicle combination and active restrictions. For example, Washington requires at least one tire chained on the last trailer axle, Oregon enforces configuration-specific rules under OAR 734-017, California requires trailer chaining when towed units have operational brakes, and Idaho requires one rear trailer axle chained when mountain pass beacons flash. Other states focus chain controls strictly on tractor drive axles.

What is Colorado’s commercial chain carry season?

Colorado’s commercial chain carry season runs from September 1 through May 31 annually. Under C.R.S. § 42-4-106 (expanded under SB24-100), commercial motor vehicles >=16,001 lbs GVWR/GCWR must carry chains on seven designated corridors: I-70 west of MP 259, CO-9 MP 63–97, US-40 west of MP 256, US-50 west of MP 225, US-160 west of MP 304, US-285 west of MP 250, and US-550 entire route (MP 0–130). Failing to carry chains carries a $67 statutory penalty, failing to install carries a $579 fine, and blocking traffic carries a $1,157 fine.

What is Washington’s commercial chain carry season and route network?

Washington’s commercial chain carry season runs from November 1 through April 1 annually under WAC 204-24-050 for vehicles over 10,000 lbs GVWR. Washington has 12 numbered designated route entries (13 individual route segments) across mountain passes including I-90 Snoqualmie Pass, US-2 Stevens Pass, US-12 White Pass, I-82 Manastash Ridge, SR-14, SR-20 West/East, US-97 Satus/Blewett, SR-155, SR-410, SR-542, and SR-970. All covered vehicles must carry minimum two extra chains beyond those mounted.

Are AutoSock and automatic tire chains legal for commercial trucks?

Alternative traction-device acceptance varies by state and active restriction level. Official sources reviewed address textile traction devices (such as AutoSock) in Colorado, Washington, Oregon, Montana, Nevada, Utah, and Wyoming, subject to specific approval conditions and device counts. Automatic tire chains are recognized on drive axles in several Western jurisdictions, but whether they satisfy full combination controls depends on state rules and whether trailer axles must also be chained.

How do drivers check whether commercial chain controls are active now?

Commercial chain controls are activated dynamically based on real-time winter storms. Drivers and fleet dispatchers must verify active status via state 511 travel portals, variable message electronic signs (VMS), highway advisory radio, and staffed highway patrol checkpoints before traveling into mountain corridors.

Commercial Motor Vehicle Regulations•Motor Carrier Winter Reference

Commercial Vehicle Chain Requirements by State

Commercial vehicle chain laws vary sharply by state, vehicle weight, axle configuration, and route. This guide compares commercial vehicle chain requirements by state, including commercial rules, seasonal carry requirements, posted chain controls, trailer requirements, and official DOT/511 sources across all 50 states.

Published by TireCalculator.net

Last reviewed: October 2026

State summaries are based on official statutes, administrative rules, and state transportation-agency guidance. Commercial chain requirements can change with route and road conditions; always check the linked official DOT/511 source before travel. Source-verified against cited official materials as of the recorded verification dates.

Calculation MethodologySources & StandardsEditorial PolicyReport a Correction

Commercial Motor Vehicle (CMV) Scope & Legal Boundary

This reference guide applies strictly to commercial motor vehicles, heavy freight trucks, tractor-semitrailers, full-trailer combinations, and commercial buses. This guide covers commercial vehicles subject to state-specific weight, vehicle-type, axle, towing, or route thresholds. The applicable trigger varies by state. It covers statutory carry windows, truck axle placement rules, trailer drag chains, alternative traction devices (ATDs), and official state DOT and 511 traveler links.

Looking for Passenger Car, SUV, or Pickup Rules?Passenger vehicles can be subject to different exemptions, thresholds, and chain-placement rules.

View Passenger Vehicle Chain Requirements →

Direct Answer Summary: 50-State Commercial Landscape

How Do Commercial Truck Tire Chain Laws Differ Across the United States?

Commercial motor vehicle tire-chain requirements are primarily established by state statutes and administrative rules rather than by a single nationwide federal chain law. Among the states reviewed, 3 have fixed seasonal commercial carry requirements, 7 use condition-based commercial chain controls, Pennsylvania uses an administrative corridor/weather-restriction framework, and the remaining 39 have no statewide commercial carry calendar or axle-placement mandate identified in the reviewed official sources.

3 States • Seasonal Carry Mandate

CO, MT, WA: Mandatory onboard chain carry calendars across designated freight corridors regardless of current road conditions.

7 States • Mandatory When Posted

CA, ID, NV, NM, OR, UT, WY: Dynamic sign-posted chain controls activated during active mountain storms and icy summit passes.

1 State • Administrative Corridor

PA: PennDOT manages commercial vehicle traction via a multi-tier winter weather event restriction plan and targeted steep-grade pilot chain-up locations.

39 States • Permitted / No Mandate

State law expressly permits the use of tire chains for safety during ice and snow, but reviewed official sources show no statewide commercial chain carry calendar or axle-placement mandate.

Complete Reference Directory

50-State Commercial Truck Chain Requirement Directory

Search by state name or postal code, or filter by regulatory classification. Each row details statutory weight thresholds, seasonal carry windows, truck drive axle placement, trailer drag requirements, and official DOT links.

Filter:

Showing 50 of 50 states

State	Status	Commercial Trigger	Carry Rule	Axle / Placement Rule	Trailer Drag Rule	Official DOT / 511
Alabama USPS: AL	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	ALDOT Motor CarrierAla. Code § 32-5-210 Live Traveler Info ↗
Alaska USPS: AK	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	Alaska DOT&PF Commercial13 AAC 04.270 Live Traveler Info ↗
Arizona USPS: AZ	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	ADOT Motor Vehicle DivisionA.R.S. § 28-958 Live Traveler Info ↗
Arkansas USPS: AR	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	ARDOT Motor CarrierArk. Code § 27-37-401 Live Traveler Info ↗
California USPS: CA	Mandatory When Posted	Caltrans illuminated electronic signs and California Highway Patrol (CHP) checkpoints posting chain control levels R-1, R-2, or R-3.	Heavy-duty vehicles with a gross weight of over 6,500 pounds	Configuration-dependent under active Caltrans chain controls; drive-axle and trailer requirements vary by vehicle combination.	Under California Vehicle Code § 27459 and Caltrans operational standards, commercial combinations operating under active chain controls must chain at least one trailer axle if the trailer is equipped with operational brakes to prevent trailing unit slide during braking.	Caltrans Commercial Vehicle OperationsCal. Veh. Code §§ 27459, 27460 Live Traveler Info ↗
Colorado USPS: CO	Mandatory Seasonal Carry	Roadside electronic VMS signs (Level 1: single-drive CMVs chain all 4 drive tires, tandem-drive may proceed if traction tires meet requirements; Level 2: all CMVs chain 4 drive tires)	September 1 through May 3116,001 lb or more GVWR / GCWR, or commercial vehicle designed to transport 16+ passengers	Configuration-dependent. Level 1 / Level 2 rules differ by single-drive and tandem-drive configuration; see Colorado details below.	Colorado statute mandates drive-axle chain placement for commercial motor vehicles; no baseline Level 1 or Level 2 trailer drag-chain mandate was identified in the reviewed statutory material.	CDOT Freight Mobility & Commercial Vehicle OperationsColo. Rev. Stat. § 42-4-106 Live Traveler Info ↗
Connecticut USPS: CT	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	CTDOT Motor CarrierConn. Gen. Stat. § 14-260 Live Traveler Info ↗
Delaware USPS: DE	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	DelDOT Motor CarrierDel. Code tit. 21, §§ 4181, 4303 Live Traveler Info ↗
Florida USPS: FL	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	FDOT Motor CarrierFla. Stat. § 316.299 Live Traveler Info ↗
Georgia USPS: GA	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	GDOT Commercial VehiclesO.C.G.A. § 40-8-74 Live Traveler Info ↗
Hawaii USPS: HI	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	HDOT Highways DivisionHaw. Rev. Stat. § 291-31 Live Traveler Info ↗
Idaho USPS: ID	Mandatory When Posted	ITD roadside electronic signs and flashing beacons indicating Chains Required on Lookout Pass / Fourth of July Pass / Lolo Pass.	Commercial motor vehicles operating on designated high-mountain pass corridors	Chains on one tire on each side of one drive axle (2 tires total).	Idaho Code § 49-948 explicitly requires commercial combinations operating on designated passes under active chain control to chain one axle at or near the rear of each towed vehicle to prevent trailer swinging and jackknifing.	Idaho Transportation Department (ITD) Commercial Vehicle ServicesIdaho Code § 49-948 Live Traveler Info ↗
Illinois USPS: IL	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	IDOT Commercial Vehicles625 ILCS 5/12-401 Live Traveler Info ↗
Indiana USPS: IN	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	INDOT Motor CarrierInd. Code § 9-19-18-3 Live Traveler Info ↗
Iowa USPS: IA	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	Iowa DOT Motor CarrierIowa Code § 321.442 Live Traveler Info ↗
Kansas USPS: KS	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	KDOT Motor CarrierKan. Stat. § 8-1742 Live Traveler Info ↗
Kentucky USPS: KY	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	KYTC Motor Carrier ServicesKRS § 189.190 Live Traveler Info ↗
Louisiana USPS: LA	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	LADOTD Motor CarrierLa. R.S. § 32:362 Live Traveler Info ↗
Maine USPS: ME	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MaineDOT Motor Carrier29-A M.R.S. § 1919 Live Traveler Info ↗
Maryland USPS: MD	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MDOT SHA CommercialMd. Code, Transp. § 21-1119 Live Traveler Info ↗
Massachusetts USPS: MA	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MassDOT Motor CarrierMass. Gen. Laws ch. 90, § 19 Live Traveler Info ↗
Michigan USPS: MI	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MDOT Commercial TransportMich. Comp. Laws § 257.710 Live Traveler Info ↗
Minnesota USPS: MN	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MnDOT Commercial VehiclesMinn. Stat. § 169.72 Live Traveler Info ↗
Mississippi USPS: MS	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MDOT Commercial VehiclesMiss. Code § 63-7-67 Live Traveler Info ↗
Missouri USPS: MO	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	MoDOT Motor Carrier ServicesMo. Rev. Stat. § 307.171 Live Traveler Info ↗
Montana USPS: MT	Mandatory Seasonal Carry	Roadside signs or electronic message boards posted by MDT or Highway Patrol stating Chains Required for Towing Units or similar directive.	October 1 through April 30Towing units with a Gross Vehicle Weight (GVW) of 26,001 pounds or greater	Tire chains must be mounted on the drive wheels of at least one drive axle (both sides).	Montana statute (MCA § 61-9-406) governs drive wheels of towing units; no specific trailer drag chain mandate was identified in reviewed sources.	Montana Department of Transportation (MDT) Motor Carrier ServicesMont. Code Ann. § 61-9-406 Live Traveler Info ↗
Nebraska USPS: NE	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	NDOT Carrier EnforcementNeb. Rev. Stat. § 60-6,250 Live Traveler Info ↗
Nevada USPS: NV	Mandatory When Posted	NDOT illuminated message boards, flashing roadside signs, or Nevada State Police checkpoints indicating Chains Required.	Commercial vehicles and combinations with a Gross Vehicle Weight (GVW) over 10,000 pounds	Approved tire chains or traction devices on driving wheels of drive axles.	NRS § 484D.515(1)(c) explicitly mandates that when chain controls are posted, vehicles over 10,000 lbs GVW towing trailers must equip traction devices on the braking wheels of the trailer in addition to the driving wheels.	Nevada Department of Transportation (NDOT) Commercial Vehicle OperationsNev. Rev. Stat. § 484D.515 Live Traveler Info ↗
New Hampshire USPS: NH	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	NHDOT Motor CarrierN.H. Rev. Stat. § 266:48 Live Traveler Info ↗
New Jersey USPS: NJ	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	NJDOT Motor CarrierN.J. Stat. § 39:3-73 Live Traveler Info ↗
New Mexico USPS: NM	Mandatory When Posted	NMDOT electronic signs and law enforcement checkpoints indicating Chains Required.	Commercial motor vehicles operating on designated high-mountain passes and steep grades	Chains or traction devices mounted on drive wheels.	New Mexico statute (NMSA § 66-3-847) governs drive wheels; no commercial trailer drag chain mandate was identified in reviewed sources.	NMDOT Commercial Vehicle OperationsN.M. Stat. Ann. § 66-3-847 Live Traveler Info ↗
New York USPS: NY	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	NYSDOT Freight & Motor CarrierN.Y. Veh. & Traf. Law § 375(35-a) Live Traveler Info ↗
North Carolina USPS: NC	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	NCDOT Commercial VehiclesN.C. Gen. Stat. § 20-122 Live Traveler Info ↗
North Dakota USPS: ND	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	NDDOT Motor Carrier ServicesN.D. Cent. Code § 39-21-40 Live Traveler Info ↗
Ohio USPS: OH	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	ODOT Commercial VehiclesOhio Rev. Code § 4513.182 Live Traveler Info ↗
Oklahoma USPS: OK	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	ODOT Motor CarrierOkla. Stat. tit. 47, § 12-405 Live Traveler Info ↗
Oregon USPS: OR	Mandatory When Posted	Variable message signs, flashing roadside beacons, or highway advisory radio indicating Chains or Traction Tires Required in designated Snow Zones.	Commercial vehicles and combinations of vehicles with a Gross Vehicle Weight (GVW) or GVWR over 10,000 pounds	Configuration-dependent under OAR 734-017. Requirements vary for solo trucks, tandem drives, semitrailers, full trailers, and multi-trailer combinations; see Oregon details below.	Oregon enforces strict configuration-specific trailer chaining under OAR 734-017-0010: tractors towing semitrailers must chain 2 tires (one on each side) of any trailer axle; trucks towing full trailers must chain 1 tire on the front axle and 1 tire on a rear axle; and B-train multi-trailer units must chain both lead and rear trailers.	ODOT Motor Carrier Transportation Division (MCTD)Or. Rev. Stat. § 815.140 Live Traveler Info ↗
Pennsylvania USPS: PA	Administrative Corridor Control	PennDOT administrative winter weather restriction tiers (Tiers 1-5) and roadside illuminated chain-up signs at pilot locations during severe winter storms.	Commercial motor vehicles over 26,000 pounds gross weight, combination units, and tractor-trailers	Chains on drive axles when chain-up signage is illuminated at steep-grade pilot locations.	PennDOT pilot steep-grade controls focus on drive axles; no statutory trailer-specific chaining mandate was identified in reviewed sources.	PennDOT Maintenance & Commercial Operations75 Pa. C.S. § 4536 Live Traveler Info ↗
Rhode Island USPS: RI	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	RIDOT Commercial VehiclesR.I. Gen. Laws § 31-23-20 Live Traveler Info ↗
South Carolina USPS: SC	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	SCDOT Commercial TransportS.C. Code § 56-5-5040 Live Traveler Info ↗
South Dakota USPS: SD	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	SDDOT Motor CarrierS.D. Codified Laws §§ 32-19-2, 32-22-41.2 Live Traveler Info ↗
Tennessee USPS: TN	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	TDOT Commercial VehiclesTenn. Code § 55-9-106 Live Traveler Info ↗
Texas USPS: TX	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	TxDOT Motor Carrier DivisionTex. Transp. Code § 547.612 Live Traveler Info ↗
Utah USPS: UT	Mandatory When Posted	UDOT illuminated electronic variable message signs, flashing roadside beacons, or Utah Highway Patrol enforcement points.	Commercial vehicles and buses with a Gross Vehicle Weight (GVW) over 12,000 pounds	Chains or traction devices must be mounted on all drive tires (for dual mountings, chains on at least one tire of each dual set).	Reviewed official Utah sources focus on traction devices on drive tires; no specific commercial trailer drag chain mandate was identified.	UDOT Motor Carrier DivisionUtah Code § 41-6a-1636 Live Traveler Info ↗
Vermont USPS: VT	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	VTrans Commercial Vehicle23 V.S.A. § 1225 Live Traveler Info ↗
Virginia USPS: VA	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	VDOT Motor CarrierVa. Code § 46.2-1044 Live Traveler Info ↗
Washington USPS: WA	Mandatory Seasonal Carry	Roadside electronic and illuminated signs posted by WSDOT (e.g., Chains Required or Chains Required on All Vehicles).	November 1 through April 1Vehicles or combinations of vehicles over 10,000 pounds Gross Vehicle Weight Rating (GVWR)	Configuration-dependent. Requirements vary by axle count, drive configuration, trailer setup, and active control level; see Washington details below.	Washington explicitly mandates trailer drag chains under WAC 204-24-050(2)(b): combination vehicles over 10,000 lbs must chain at least one tire on the last axle of the last trailer or semi-trailer (either of the last two axles if tandem) to provide directional drag stability and prevent jackknifing during winter descents.	WSDOT Commercial Vehicle ServicesWash. Rev. Code § 47.36.250 Live Traveler Info ↗
West Virginia USPS: WV	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	WVDOT Motor CarrierW. Va. Code § 17C-15-37 Live Traveler Info ↗
Wisconsin USPS: WI	Permitted / No State CMV Mandate	No specific commercial chain mandate found in reviewed official sources.	No fixed commercial carry calendar found in reviewed official sources.	No commercial-specific axle-placement mandate found in reviewed official sources.	No commercial-specific trailer-chain mandate found in reviewed official sources.	WisDOT Motor CarriersWis. Stat. § 347.45 Live Traveler Info ↗
Wyoming USPS: WY	Mandatory When Posted	WYDOT electronic variable message signs displaying Level 1 or Level 2 chain restrictions.	Commercial vehicles operating on Wyoming state highways and interstate mountain corridors	Chains mounted on at least two drive wheels at opposite ends of the same drive axle.	Wyoming statute (W.S. 31-5-956) specifies drive axle placement; no statutory trailer drag chain mandate was identified in reviewed sources.	Wyoming Department of Transportation (WYDOT) Commercial Vehicle SectionWyo. Stat. § 31-5-956 Live Traveler Info ↗

Alabama (AL)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

ALDOT Motor CarrierAla. Code § 32-5-210

Live Traveler Info ↗

Alaska (AK)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

Alaska DOT&PF Commercial13 AAC 04.270

Live Traveler Info ↗

Arizona (AZ)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

ADOT Motor Vehicle DivisionA.R.S. § 28-958

Live Traveler Info ↗

Arkansas (AR)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

ARDOT Motor CarrierArk. Code § 27-37-401

Live Traveler Info ↗

California (CA)

Threshold: Heavy-duty vehicles with a gross weight of over 6,500 pounds

Mandatory When Posted

Carry & Activation Trigger

Caltrans illuminated electronic signs and California Highway Patrol (CHP) checkpoints posting chain control levels R-1, R-2, or R-3.

Truck Drive Axle Rule

Configuration-dependent under active Caltrans chain controls; drive-axle and trailer requirements vary by vehicle combination.

Trailer Drag Chain Rule

Under California Vehicle Code § 27459 and Caltrans operational standards, commercial combinations operating under active chain controls must chain at least one trailer axle if the trailer is equipped with operational brakes to prevent trailing unit slide during braking.

Caltrans Commercial Vehicle OperationsCal. Veh. Code §§ 27459, 27460

Live Traveler Info ↗

Colorado (CO)

Threshold: 16,001 lb or more GVWR / GCWR, or commercial vehicle designed to transport 16+ passengers

Mandatory Seasonal Carry

Carry & Activation Trigger

Mandatory Carry: September 1 through May 31Roadside electronic VMS signs (Level 1: single-drive CMVs chain all 4 drive tires, tandem-drive may proceed if traction tires meet requirements; Level 2: all CMVs chain 4 drive tires)

Truck Drive Axle Rule

Configuration-dependent. Level 1 / Level 2 rules differ by single-drive and tandem-drive configuration; see Colorado details below.

Trailer Drag Chain Rule

Colorado statute mandates drive-axle chain placement for commercial motor vehicles; no baseline Level 1 or Level 2 trailer drag-chain mandate was identified in the reviewed statutory material.

CDOT Freight Mobility & Commercial Vehicle OperationsColo. Rev. Stat. § 42-4-106

Live Traveler Info ↗

Connecticut (CT)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

CTDOT Motor CarrierConn. Gen. Stat. § 14-260

Live Traveler Info ↗

Delaware (DE)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

DelDOT Motor CarrierDel. Code tit. 21, §§ 4181, 4303

Live Traveler Info ↗

Florida (FL)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

FDOT Motor CarrierFla. Stat. § 316.299

Live Traveler Info ↗

Georgia (GA)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

GDOT Commercial VehiclesO.C.G.A. § 40-8-74

Live Traveler Info ↗

Hawaii (HI)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

HDOT Highways DivisionHaw. Rev. Stat. § 291-31

Live Traveler Info ↗

Idaho (ID)

Threshold: Commercial motor vehicles operating on designated high-mountain pass corridors

Mandatory When Posted

Carry & Activation Trigger

ITD roadside electronic signs and flashing beacons indicating Chains Required on Lookout Pass / Fourth of July Pass / Lolo Pass.

Truck Drive Axle Rule

Chains on one tire on each side of one drive axle (2 tires total).

Trailer Drag Chain Rule

Idaho Code § 49-948 explicitly requires commercial combinations operating on designated passes under active chain control to chain one axle at or near the rear of each towed vehicle to prevent trailer swinging and jackknifing.

Idaho Transportation Department (ITD) Commercial Vehicle ServicesIdaho Code § 49-948

Live Traveler Info ↗

Illinois (IL)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

IDOT Commercial Vehicles625 ILCS 5/12-401

Live Traveler Info ↗

Indiana (IN)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

INDOT Motor CarrierInd. Code § 9-19-18-3

Live Traveler Info ↗

Iowa (IA)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

Iowa DOT Motor CarrierIowa Code § 321.442

Live Traveler Info ↗

Kansas (KS)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

KDOT Motor CarrierKan. Stat. § 8-1742

Live Traveler Info ↗

Kentucky (KY)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

KYTC Motor Carrier ServicesKRS § 189.190

Live Traveler Info ↗

Louisiana (LA)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

LADOTD Motor CarrierLa. R.S. § 32:362

Live Traveler Info ↗

Maine (ME)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MaineDOT Motor Carrier29-A M.R.S. § 1919

Live Traveler Info ↗

Maryland (MD)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MDOT SHA CommercialMd. Code, Transp. § 21-1119

Live Traveler Info ↗

Massachusetts (MA)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MassDOT Motor CarrierMass. Gen. Laws ch. 90, § 19

Live Traveler Info ↗

Michigan (MI)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MDOT Commercial TransportMich. Comp. Laws § 257.710

Live Traveler Info ↗

Minnesota (MN)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MnDOT Commercial VehiclesMinn. Stat. § 169.72

Live Traveler Info ↗

Mississippi (MS)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MDOT Commercial VehiclesMiss. Code § 63-7-67

Live Traveler Info ↗

Missouri (MO)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

MoDOT Motor Carrier ServicesMo. Rev. Stat. § 307.171

Live Traveler Info ↗

Montana (MT)

Threshold: Towing units with a Gross Vehicle Weight (GVW) of 26,001 pounds or greater

Mandatory Seasonal Carry

Carry & Activation Trigger

Mandatory Carry: October 1 through April 30Roadside signs or electronic message boards posted by MDT or Highway Patrol stating Chains Required for Towing Units or similar directive.

Truck Drive Axle Rule

Tire chains must be mounted on the drive wheels of at least one drive axle (both sides).

Trailer Drag Chain Rule

Montana statute (MCA § 61-9-406) governs drive wheels of towing units; no specific trailer drag chain mandate was identified in reviewed sources.

Montana Department of Transportation (MDT) Motor Carrier ServicesMont. Code Ann. § 61-9-406

Live Traveler Info ↗

Nebraska (NE)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

NDOT Carrier EnforcementNeb. Rev. Stat. § 60-6,250

Live Traveler Info ↗

Nevada (NV)

Threshold: Commercial vehicles and combinations with a Gross Vehicle Weight (GVW) over 10,000 pounds

Mandatory When Posted

Carry & Activation Trigger

NDOT illuminated message boards, flashing roadside signs, or Nevada State Police checkpoints indicating Chains Required.

Truck Drive Axle Rule

Approved tire chains or traction devices on driving wheels of drive axles.

Trailer Drag Chain Rule

NRS § 484D.515(1)(c) explicitly mandates that when chain controls are posted, vehicles over 10,000 lbs GVW towing trailers must equip traction devices on the braking wheels of the trailer in addition to the driving wheels.

Nevada Department of Transportation (NDOT) Commercial Vehicle OperationsNev. Rev. Stat. § 484D.515

Live Traveler Info ↗

New Hampshire (NH)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

NHDOT Motor CarrierN.H. Rev. Stat. § 266:48

Live Traveler Info ↗

New Jersey (NJ)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

NJDOT Motor CarrierN.J. Stat. § 39:3-73

Live Traveler Info ↗

New Mexico (NM)

Threshold: Commercial motor vehicles operating on designated high-mountain passes and steep grades

Mandatory When Posted

Carry & Activation Trigger

NMDOT electronic signs and law enforcement checkpoints indicating Chains Required.

Truck Drive Axle Rule

Chains or traction devices mounted on drive wheels.

Trailer Drag Chain Rule

New Mexico statute (NMSA § 66-3-847) governs drive wheels; no commercial trailer drag chain mandate was identified in reviewed sources.

NMDOT Commercial Vehicle OperationsN.M. Stat. Ann. § 66-3-847

Live Traveler Info ↗

New York (NY)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

NYSDOT Freight & Motor CarrierN.Y. Veh. & Traf. Law § 375(35-a)

Live Traveler Info ↗

North Carolina (NC)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

NCDOT Commercial VehiclesN.C. Gen. Stat. § 20-122

Live Traveler Info ↗

North Dakota (ND)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

NDDOT Motor Carrier ServicesN.D. Cent. Code § 39-21-40

Live Traveler Info ↗

Ohio (OH)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

ODOT Commercial VehiclesOhio Rev. Code § 4513.182

Live Traveler Info ↗

Oklahoma (OK)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

ODOT Motor CarrierOkla. Stat. tit. 47, § 12-405

Live Traveler Info ↗

Oregon (OR)

Threshold: Commercial vehicles and combinations of vehicles with a Gross Vehicle Weight (GVW) or GVWR over 10,000 pounds

Mandatory When Posted

Carry & Activation Trigger

Variable message signs, flashing roadside beacons, or highway advisory radio indicating Chains or Traction Tires Required in designated Snow Zones.

Truck Drive Axle Rule

Configuration-dependent under OAR 734-017. Requirements vary for solo trucks, tandem drives, semitrailers, full trailers, and multi-trailer combinations; see Oregon details below.

Trailer Drag Chain Rule

Oregon enforces strict configuration-specific trailer chaining under OAR 734-017-0010: tractors towing semitrailers must chain 2 tires (one on each side) of any trailer axle; trucks towing full trailers must chain 1 tire on the front axle and 1 tire on a rear axle; and B-train multi-trailer units must chain both lead and rear trailers.

ODOT Motor Carrier Transportation Division (MCTD)Or. Rev. Stat. § 815.140

Live Traveler Info ↗

Pennsylvania (PA)

Threshold: Commercial motor vehicles over 26,000 pounds gross weight, combination units, and tractor-trailers

Administrative Corridor Control

Carry & Activation Trigger

PennDOT administrative winter weather restriction tiers (Tiers 1-5) and roadside illuminated chain-up signs at pilot locations during severe winter storms.

Truck Drive Axle Rule

Chains on drive axles when chain-up signage is illuminated at steep-grade pilot locations.

Trailer Drag Chain Rule

PennDOT pilot steep-grade controls focus on drive axles; no statutory trailer-specific chaining mandate was identified in reviewed sources.

PennDOT Maintenance & Commercial Operations75 Pa. C.S. § 4536

Live Traveler Info ↗

Rhode Island (RI)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

RIDOT Commercial VehiclesR.I. Gen. Laws § 31-23-20

Live Traveler Info ↗

South Carolina (SC)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

SCDOT Commercial TransportS.C. Code § 56-5-5040

Live Traveler Info ↗

South Dakota (SD)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

SDDOT Motor CarrierS.D. Codified Laws §§ 32-19-2, 32-22-41.2

Live Traveler Info ↗

Tennessee (TN)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

TDOT Commercial VehiclesTenn. Code § 55-9-106

Live Traveler Info ↗

Texas (TX)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

TxDOT Motor Carrier DivisionTex. Transp. Code § 547.612

Live Traveler Info ↗

Utah (UT)

Threshold: Commercial vehicles and buses with a Gross Vehicle Weight (GVW) over 12,000 pounds

Mandatory When Posted

Carry & Activation Trigger

UDOT illuminated electronic variable message signs, flashing roadside beacons, or Utah Highway Patrol enforcement points.

Truck Drive Axle Rule

Chains or traction devices must be mounted on all drive tires (for dual mountings, chains on at least one tire of each dual set).

Trailer Drag Chain Rule

Reviewed official Utah sources focus on traction devices on drive tires; no specific commercial trailer drag chain mandate was identified.

UDOT Motor Carrier DivisionUtah Code § 41-6a-1636

Live Traveler Info ↗

Vermont (VT)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

VTrans Commercial Vehicle23 V.S.A. § 1225

Live Traveler Info ↗

Virginia (VA)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

VDOT Motor CarrierVa. Code § 46.2-1044

Live Traveler Info ↗

Washington (WA)

Threshold: Vehicles or combinations of vehicles over 10,000 pounds Gross Vehicle Weight Rating (GVWR)

Mandatory Seasonal Carry

Carry & Activation Trigger

Mandatory Carry: November 1 through April 1Roadside electronic and illuminated signs posted by WSDOT (e.g., Chains Required or Chains Required on All Vehicles).

Truck Drive Axle Rule

Configuration-dependent. Requirements vary by axle count, drive configuration, trailer setup, and active control level; see Washington details below.

Trailer Drag Chain Rule

Washington explicitly mandates trailer drag chains under WAC 204-24-050(2)(b): combination vehicles over 10,000 lbs must chain at least one tire on the last axle of the last trailer or semi-trailer (either of the last two axles if tandem) to provide directional drag stability and prevent jackknifing during winter descents.

WSDOT Commercial Vehicle ServicesWash. Rev. Code § 47.36.250

Live Traveler Info ↗

West Virginia (WV)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

WVDOT Motor CarrierW. Va. Code § 17C-15-37

Live Traveler Info ↗

Wisconsin (WI)

Threshold: No fixed commercial carry calendar found in reviewed official sources.

Permitted / No State CMV Mandate

Carry & Activation Trigger

No specific commercial chain mandate found in reviewed official sources.

Truck Drive Axle Rule

No commercial-specific axle-placement mandate found in reviewed official sources.

Trailer Drag Chain Rule

No commercial-specific trailer-chain mandate found in reviewed official sources.

WisDOT Motor CarriersWis. Stat. § 347.45

Live Traveler Info ↗

Wyoming (WY)

Threshold: Commercial vehicles operating on Wyoming state highways and interstate mountain corridors

Mandatory When Posted

Carry & Activation Trigger

WYDOT electronic variable message signs displaying Level 1 or Level 2 chain restrictions.

Truck Drive Axle Rule

Chains mounted on at least two drive wheels at opposite ends of the same drive axle.

Trailer Drag Chain Rule

Wyoming statute (W.S. 31-5-956) specifies drive axle placement; no statutory trailer drag chain mandate was identified in reviewed sources.

Wyoming Department of Transportation (WYDOT) Commercial Vehicle SectionWyo. Stat. § 31-5-956

Live Traveler Info ↗

Figure 1: Mechanical Reference

Commercial Axle Terminology & Representative Chain Placement

5-Axle Tractor-Trailer Layout

Figure 1: Example axle terminology on a 5-axle tractor-semitrailer. Highlighted areas identify common drive-axle and trailer drag-chain terminology; they do not prescribe a universal chain configuration. Required placement varies by state, vehicle configuration, and active control level.

Figure 2: Operational Flow

Seasonal Carry Mandates vs. Active Chain-Up Orders

Two-Stage Compliance Logic

Figure 2: Two-stage operational decision logic for commercial motor vehicles in winter mountain corridors. Stage 1 mandates carrying the required chains or approved traction devices during a statutory carry period (CO, WA, MT). Stage 2 requires physically installing them on the axles required by the applicable state rule and vehicle configuration when roadside signs or highway patrol checkpoints activate controls.

State-by-State Primary Legal Analysis

Western Mountain Pass Commercial Regulations & Statutory Corridors

Detailed statutory requirements, configuration-specific axle matrices, designated highway segments, and penalty structures across the key Western freight corridors.

State Law Deep Dive • Mandatory Carry Corridor

Colorado: Expanded 7-Corridor Network & C.R.S. § 42-4-106 (SB24-100)

Sep 1 – May 31 Carry Mandate

Under Colorado Revised Statutes § 42-4-106 and Colorado Department of Transportation (CDOT) administrative rules (2 CCR 601-14), commercial motor vehicles with a Gross Vehicle Weight Rating (GVWR) or Gross Combination Weight Rating (GCWR) of 16,001 pounds or greater (or passenger-capacity vehicles designed to transport 16 or more passengers) must carry sufficient tire chains or approved alternative traction devices to chain four drive wheels when operating in designated mountain corridors between September 1 and May 31 annually.

Following the passage of Colorado Senate Bill 24-100 (SB24-100), Colorado’s mandatory commercial chain carry requirement was codified across seven designated mountain corridors west of Morrison and Denver:

#	Designated Highway	Milepost Boundaries	Statutory Authority
1	Interstate 70	West of MP 259 (Morrison) to Utah state line (MP 0)	C.R.S. § 42-4-106(5)(a)(I)
2	State Highway 9	MP 63 to MP 97 (Frisco to Fairplay / Hoosier Pass)	C.R.S. § 42-4-106(5)(a)(I.5)(A)
3	U.S. Highway 40	West of MP 256 (Empire) to Utah state line (Berthoud Pass / Rabbit Ears Pass)	C.R.S. § 42-4-106(5)(a)(I.5)(B)
4	U.S. Highway 50	West of MP 225 (Salida) to Utah state line (Monarch Pass)	C.R.S. § 42-4-106(5)(a)(I.5)(C)
5	U.S. Highway 160	West of MP 304 (Walsenburg) to New Mexico state line (Wolf Creek Pass)	C.R.S. § 42-4-106(5)(a)(I.5)(D)
6	U.S. Highway 285	West of MP 250 (Morrison) to New Mexico state line (Kenosha Pass / Red Hill Pass)	C.R.S. § 42-4-106(5)(a)(I.5)(E)
7	U.S. Highway 550	Entire route MP 0 to MP 130 (New Mexico state line to Montrose / Red Mountain Pass)	C.R.S. § 42-4-106(5)(a)(I.5)(F)

Level 1 vs. Level 2 Chain Controls

Level 1: All single-drive axle CMVs must chain all four drive tires. Tandem-drive CMVs may proceed unchained if equipped with qualifying traction tires.
Level 2: All commercial motor vehicles must chain four drive tires without drivetrain exception.

Statutory Fines (C.R.S. § 42-4-1701)

• $67 total ($50 fine + $17 surcharge) for failing to carry chains.
• $579 total ($500 fine + $79 surcharge) for failing to install when active.
• $1,157 total ($1,000 fine + $157 surcharge) for blocking highway traffic.

State Law Deep Dive • Mandatory Carry Corridor & Spares

Washington: 12-Entry / 13-Segment Corridors & WAC 204-24-050

Nov 1 – Apr 1 Carry Mandate

Washington Administrative Code (WAC) 204-24-050 and Revised Code of Washington (RCW) § 47.36.250 govern commercial vehicles and combinations over 10,000 pounds GVWR. Between November 1 and April 1, all covered vehicles must carry approved chains or traction devices when traveling over designated mountain passes regardless of weather.

Washington has 12 designated route entries under WAC 204-24-050 for the November 1–April 1 commercial chain-carry requirement. Because entry (vi) for State Route 20 contains two distinct highway segments (West and East passes), the normalized dataset stores 13 individual route segments:

WAC #	Segment	Highway	Milepost Boundaries	Named Pass / Corridor
(i)	#1	Interstate 90	MP 32.00 (North Bend) to MP 101.00 (Ellensburg)	Snoqualmie Pass
(ii)	#2	Interstate 82	MP 3.00 (Ellensburg Exit 3) to MP 26.00 (Selah Exit 26)	Manastash Ridge
(iii)	#3	State Route 2 (US-2)	MP 36.00 (Index) to MP 108.00 (Dryden)	Stevens Pass
(iv)	#4	State Route 12 (US-12)	MP 135.00 (Packwood) to MP 187.00 (Naches)	White Pass
(v)	#5	State Route 14	MP 18.00 (Gibbons Creek) to MP 108.40 (Cliffs Road Intersection)	Columbia River Gorge
(vi)	#6	State Route 20 (West)	MP 120.00 (Newhalem) to MP 192.00 (Winthrop)	North Cascades Highway
(vi)	#7	State Route 20 (East)	MP 262.00 (Tonasket) to MP 342.00 (Kettle Falls)	Wauconda Pass & Sherman Pass
(vii)	#8	State Route 97 (US-97 Satus)	MP 0.00 (Columbia River / Maryhill) to MP 59.00 (Toppenish)	Satus Pass
(vii)	#9	State Route 97 (US-97 Blewett)	MP 145.00 (Virden) to Junction with SR-2 (MP 149.69 / Peshastin)	Blewett Pass
(viii)	#10	State Route 155	MP 45.00 (Nespelem) to MP 79.00 (Omak)	Disautel Pass
(ix)	#11	State Route 410	Enumclaw (MP 24.40) to Naches (MP 113.10)	Chinook Pass & Cayuse Pass approaches
(x)	#12	State Route 542	MP 22.91 (Glacier) to MP 57.26 (Artist Point / Mt. Baker)	Mount Baker Highway
(xi)	#13	State Route 970	MP 0.00 (Cle Elum) to MP 10.00 (Junction with US-97)	Teanaway Corridor

Mandatory Spare Chains & Construction

All vehicles over 10,000 lbs must carry at least two (2) extra chains in reserve beyond those mounted. Chains must feature hardened metal cross-chains; plastic chains are strictly prohibited.

Trailer Drag Chain Requirement

Combinations towing trailers must chain one tire on the last axle of the last trailer or semi-trailer (either axle if tandem) to prevent trailer swinging during braking descents.

State Law Deep Dive • Condition-Based Snow Zones

Oregon: 9 Axle Configurations & OAR Chapter 734, Division 17

Posted Snow Zone Activation

Oregon Revised Statutes § 815.140 and Oregon Administrative Rules (OAR) Chapter 734, Division 17 establish traction device standards for commercial vehicles over 10,000 pounds GVWR. Oregon enforces no fixed statewide calendar carry mandate; rules activate dynamically when roadside signs or flashing beacons are displayed in designated Snow Zones (e.g., Mount Hood, Siskiyou Summit on I-5, Santiam Pass).

Under OAR 734-017-0010, Oregon establishes nine distinct configuration-specific placement matrices. Tractor-semitrailer combinations must chain two tires (one each side) of any semi-trailer axle; full trailers must chain front and rear trailer axles; and B-train multi-trailers must chain both lead and rear units.

State Law Deep Dive • Caltrans Highway Maintenance

California: Heavy-Duty Rules, Control Levels & 30 MPH Limit

Checkpoint & Sign Activated

Under California Vehicle Code §§ 27459 and 27460 and Caltrans Highway Maintenance Manual § 8.04, commercial rules apply to heavy-duty vehicles over 6,500 pounds gross weight. California does not impose a fixed calendar carry window; controls are activated dynamically via illuminated roadside signs and California Highway Patrol (CHP) checkpoints.

Under Level R-1, heavy-duty commercial vehicles over 6,500 lbs gross weight must mount chains and do not receive the passenger snow-tire exemption. Under Level R-2, all commercial vehicles must chain drive axles. In addition, when commercial combinations tow trailers equipped with operational brakes, at least one trailer axle must be chained. The statutory speed limit when chains are installed is strictly 30 mph statewide.

Montana • MCA § 61-9-406

Towing units with a GVW of 26,001 pounds or greater must carry chains between October 1 and April 30. When signs are posted, chains must be mounted on the drive wheels of at least one drive axle. Standard penalty is $250 ($750 if an incident closes all lanes).

Nevada • NRS § 484D.515

Vehicles over 10,000 lbs GVW must install traction devices on drive wheels and the braking wheels of the trailer when signs are illuminated on mountain passes (such as I-80 Donner approach or Mount Rose Highway).

Utah • Utah Code § 41-6a-1636 & R920-6

Commercial vehicles over 12,000 lbs GVW must equip approved traction devices on all drive tires when posted by UDOT variable message signs. For dual tire mountings, chains must be on at least one tire of each dual set.

Idaho • Idaho Code § 49-948

Commercial vehicles operating on designated pass corridors (I-90 Lookout & Fourth of July Passes; US-12 Lolo Pass) must chain drive wheels PLUS one axle at or near the rear of each towed vehicle when beacons flash.

Wyoming • Wyo. Stat. § 31-5-956

WYDOT activates dynamic Level 1 (chains or adequate snow tires) and Level 2 (chains required on drive wheels) restrictions via electronic VMS signs across high-elevation interstate summits (I-80 Sherman Hill, Elk Mountain). Fines range up to $250, increasing to up to $750 if noncompliance causes a highway closure.

Mechanical & Operational Standards

Commercial Axle Placement, Super Singles & Trailer Drag Chains

Chaining a commercial combination is mechanically distinct from equipping passenger vehicles. Heavy commercial tractors require careful weight distribution, differential traction balance across tandem drive axles, and directional drag stability on trailing units.

Steer Axle

The steer axle is the front steering axle of the tractor. This guide does not apply a universal chain-placement rule to it; follow the applicable state control, vehicle configuration requirements, and manufacturer clearance guidance.

Drive Tandem Axles

Drive-axle placement varies by state, control level, and vehicle configuration. Some rules specify outer tires across tandem drive axles, while others specify tires on one powered axle. Use the state-specific requirements above rather than applying one configuration nationally. Where wide-base "super single" tires are used, check state-specific regulations for dedicated single-tire placement rules.

Trailer Drag Chains

Trailer drag chains can add braking-direction stability on snow or ice where state rules require them. Whether a trailer axle must be chained depends on the state, vehicle combination, and active restriction.

Approved Equipment Specifications

Alternative Traction Devices (ATDs) & Automatic Tire Chains

Textile Traction Devices (AutoSock)

Alternative traction-device acceptance varies by state and by active restriction. Official sources reviewed address textile devices in Colorado, Washington, Oregon, Montana, Nevada, Utah, and Wyoming. Check the applicable DOT, highway patrol, or administrative rule before relying on a textile device to satisfy a carry or installation requirement.

Automatic Tire Chains (Onspot / Insta-Chain)

Some reviewed states recognize automatic traction devices for commercial drive axles. Whether an automatic system satisfies a specific chain-control requirement depends on the state, vehicle configuration, and any separate trailer-chain requirement. Verify the applicable DOT or patrol rule before travel.

Federal Regulatory Compliance Framework

How Federal Regulations (49 CFR) Interact With State Chain Laws

Federal regulations do not establish a nationwide tire-chain carry calendar or universal chain-up mandate. Instead, federal motor carrier safety standards govern winter traction through two operational provisions:

49 CFR § 392.2 (Applicable operating rules): Every commercial motor vehicle must be operated in accordance with the laws, ordinances, and regulations of the jurisdiction in which it is being operated. Violations of state or local operating laws may be recorded under § 392.2 when cited during a qualifying roadside commercial vehicle inspection.
49 CFR § 392.14 (Hazardous conditions; extreme caution): Drivers must exercise extreme caution when hazardous conditions—such as snow, ice, or sleet—adversely affect traction or visibility, and must stop operating if conditions become sufficiently dangerous.

Common Questions & Practical Answers

Frequently Asked Questions About Commercial Truck Chain Laws

Methodology & Regulatory Provenance

Authoritative Primary Sources & Commercial Transportation Authorities

Commercial vehicle summaries are based strictly on cited state statutes, administrative codes, and official transportation-agency operating manuals. Road conditions and emergency chain orders change dynamically; the linked official DOT/511 sources represent current operational references. Key primary statutory references include:

ColoradoC.R.S. § 42-4-106 & CDOT 2 CCR 601-14 (SB24-100)

WashingtonRCW § 47.36.250 & WAC 204-24-050

OregonORS § 815.140 & OAR 734-017

CaliforniaCVC §§ 27459, 27460 & Caltrans Maintenance Manual § 8.04

MontanaMCA § 61-9-406 & MDT Motor Carrier Services

Federal Standard49 CFR § 392.2 & 49 CFR § 392.14