Winter TyresUS Winter Tyres 2026: Chain Controls, Not a Federal Rule
No federal US winter-tyre law. States set the rules: California's R-1 to R-3 chain controls, Colorado's traction law (USD 100 + surcharge), Washington studs 1 Nov-31 Mar.
No federal law in the United States requires winter tyres. Winter equipment rules are made by states, and on the roads where they matter they usually take the form of chain controls or traction laws switched on for specific mountain highways during storms. Stud seasons, tread rules and fines differ from state to state.
California: three levels of chain control
When Caltrans posts chain controls on routes such as I-80 over Donner Summit or US-50 to Lake Tahoe, the level on the sign decides what you need:
| Level | Requirement |
|---|---|
| R-1 | Chains on all vehicles except passenger vehicles and light trucks under 6,000 lb with snow tyres on at least two drive wheels (which must still carry chains) |
| R-2 | Chains or traction devices on all vehicles except four- or all-wheel drive vehicles with snow-tread tyres on all four wheels (which must still carry traction devices) |
| R-3 | Chains or traction devices on all vehicles, no exceptions |
Chain installers at the control points are not allowed to sell or rent chains, so they need to be in the car before the climb.
Colorado: traction law and chain law
Colorado runs two tiers. Under the Traction Law, compliant options include four- or all-wheel drive vehicles on tyres marked M+S or with the mountain-snowflake symbol and at least 3/16 inch of tread. In severe storms the Chain Law can be called, requiring every vehicle to have chains or an approved alternative traction device.
Fines: USD 100 plus a USD 33 surcharge for a vehicle out of compliance, and USD 500 plus a USD 157 surcharge if that vehicle blocks the highway and causes a closure. Current status is posted on COtrip.org.
Studded tyres: a state-by-state season
Each state sets its own stud window, and the dates differ by weeks. Washington adds that there are no out-of-state waivers: visitors follow the rules of the state they are driving in.
| State | Studs legal | Legal basis |
|---|---|---|
| Washington | 1 November – 31 March ($137 ticket from 1 April) | RCW 46.37.420; WSDOT |
| Oregon | 1 November – 31 March | ORS 815.165 |
| California | 1 November – 30 April | Vehicle Code 27454 |
| Idaho | 1 October – 30 April | Idaho Code 49-948 |
| Montana | 1 October – 31 May | MCA 61-9-406 |
| Nevada | 1 October – 30 April | NRS 484D.510 |
| Utah | 15 October – 31 March | Utah Code 41-6a-1636 |
| New York | 16 October – 30 April | Vehicle and Traffic Law 375 |
| Alaska, north of 60°N | 16 September – 30 April (Anchorage city limits from 1 October) | Alaska DOT&PF |
| Alaska, south of 60°N | 1 October – 14 April | Alaska DOT&PF |
| Minnesota | Banned on Minnesota vehicles; visitors up to 30 days in six months | Minn. Stat. 169.72 |
A spring drive from Idaho or Montana into Washington or Oregon after 31 March is the commonest way to get caught out.
Oregon: chains where signs say so
Oregon posts traction-tyre or chain requirements on specific sections. Driving past the signs without the required equipment is a Class C traffic violation with a USD 165 presumptive fine. A 4WD or AWD vehicle of 6,500 lb or less unloaded, on traction tyres on all wheels, not towing and carrying chains, may skip fitting them.
Tread depth
Tread-depth minimums for passenger cars are also set by states rather than federally, so the requirement is whatever the state you are driving in sets. For winter mountain driving, Colorado’s 3/16 inch traction-law figure is a useful yardstick.
Sources
- Caltrans, Chain controls — R-1, R-2 and R-3 requirements; installers may not sell or rent chains.
- Colorado DOT, Traction Law and Passenger Vehicle Chain Law — compliant tyres, 3/16 inch, fines and surcharges.
- Washington State DOT, Clock is ticking: Washington’s studded tire deadline is March 31 — 1 November to 31 March, USD 137 ticket, no out-of-state waivers.
- Washington State Legislature, RCW 46.37.420 — stud period 1 November to 1 April.
- Oregon Legislature, ORS chapter 815 and ORS 153.019 — chain signs, 4WD exemption, stud season, USD 165 Class C fine.
- California Legislative Information, Vehicle Code 27454 — studs 1 November to 30 April.
- Idaho Legislature, Idaho Code 49-948 — studs banned 1 May to 30 September.
- Montana Legislature, MCA 61-9-406 — embedded-stud tyres 1 October to 31 May.
- Nevada Legislature, NRS 484D.510 — studs 1 October to 30 April.
- Utah Legislature, Utah Code 41-6a-1636 — studs 15 October to 31 March.
- New York State Senate, Vehicle and Traffic Law 375 — studs barred 1 May to 15 October.
- Alaska DOT&PF, Studded tires — dates north and south of 60°N, Anchorage ordinance 19-13.
- Minnesota Revisor of Statutes, Minn. Stat. 169.72 — stud ban, visitor exception, chains.
More on the United States
Crossing more than one border this winter? See winter tyre rules, dates and legal tread minimums for every country →
Tyre details
- Winter tyre rated below your car's top speed? Read the speed letter — H, V, W and Y decoded, plus the sticker rule for lower-rated winter sets.
- Load index: will the tyre carry a loaded car? — The two- or three-digit number that caps weight per tyre.
- EU tyre label grades for wet grip and fuel use — What each letter and pictogram on the sticker actually measures.
- Tyre noise ratings in decibels — What the dB figure and the A, B or C class on the label mean inside the car.
- Starting tyre pressure for your size and load — A starting figure in bar and psi, then the door placard has the final word.
Full rules, fines & requirements
Winter tyres, tread depth & rules
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Related Questions
Not by federal law. Requirements come from individual states and usually take the form of chain controls or traction laws that switch on for specific mountain highways during storms.
Caltrans posts three levels. R-1: chains on all vehicles except cars and light trucks under 6,000 lb with snow tyres on at least two drive wheels. R-2: chains on all vehicles except four- or all-wheel drive vehicles with snow-tread tyres on all four wheels. R-3: chains on all vehicles, no exceptions.
When it is in effect, a vehicle needs, among the accepted options, four- or all-wheel drive with M+S or mountain-snowflake tyres of at least 3/16 inch tread, or chains or an approved traction device. Non-compliance costs USD 100 plus a USD 33 surcharge; if the vehicle blocks the road, USD 500 plus a USD 157 surcharge.
It depends on the state. In Washington, for example, studded tyres are legal from 1 November to 31 March; after that, the State Patrol can issue a USD 137 ticket.