Chain control and snow tires out of Los Angeles

Los Angeles does not get snow. On the NOAA 1991-2020 annual normals the snowfall figure at Los Angeles International and at Burbank is 0.0 inches, with 0.0 days a year of a tenth of an inch or more, and all four Los Angeles stations average 0.0 days a year with a maximum at or below freezing.

And yet Los Angeles County contains thirty-one signed Caltrans chain-control points, the highest of them at 6,804 feet. You can leave a 75F afternoon in Van Nuys and be standing at a posted gate above six thousand feet, inside the same county, within the hour.

This page is about that drive. It is not about your commute, and anyone selling you winter tires for Ventura Boulevard is selling you something you do not need.

Where the thirty-one gates are

The live Caltrans District 7 chain-control feed, read on 2026-09-20 at 18:06:02, carried 43 control points, of which 31 are in Los Angeles County. The other twelve are in Ventura, Kern and San Luis Obispo. The 31 sit on five routes:

Route	Control points in LA County	Notes
SR-2, Angeles Crest Highway	11	From the La Cañada gate at 1,932 ft up through Georges Gap, Red Box, Charlton Flats, Newcomb's Ranch, Kratka Ridge and Islip Saddle at 6,686 ft
SR-14	6	From Shadow Pines Boulevard up to the Los Angeles–Kern county line
SR-39	6	Above Azusa
I-5	4	Lake Hughes Road, Castaic Junction, Hungry Valley Road, Frazier Mountain Park Road
SR-138	4

Elevations in the feed run from 1,026 feet at Castaic Junction to 6,804 feet at Kratka Ridge. Angeles Crest alone accounts for eleven of the thirty-one. All 31 read R-0 at the time of that pull, which is what you would expect on 20 September; this is a winter and shoulder-season rule, not a today rule.

Those counts are over the full published District 7 feed as it stood that evening. Each record is one signed control point in one direction, so a route signed both ways carries more than one record.

What the rating letters mean, in Caltrans's own words

From the Caltrans Chain Control Status Chart, read 2026-09-20:

R-0 No chain controls are in effect at this time. R-1 Chains, traction devices or snow tires are required on the drive axle of all vehicles except four wheel or all wheel drive vehicles. R-1 MODIFIED Trucks and vehicles pulling trailers require chains, traction devices or snow tires on the drive axle of all vehicles except four wheel or all wheel drive vehicles. R-2 Chains or traction devices are required on all vehicles except four wheel / all wheel drive vehicles with snow treaded tires on all wheels. R-3 Chains or traction devices are required on all vehicles, no exceptions.

Read R-2 carefully. The four-wheel-drive exemption is conditional on snow-treaded tires on all wheels, not on the badge on the tailgate.

The tread number that changes at the gate

This is the part almost nobody knows, and it is the reason this page exists.

California's tread minimum for a passenger car is one thirty-second of an inch in any two adjacent grooves, under CVC 27465(b)(1). That is the subject of the California tread law page, and it is half the familiar 2/32 figure.

Three paragraphs later, the same section says:

(3) Six thirty-second (6/32) of an inch tread depth at all points in all major grooves on snow tires used in lieu of tire traction devices in posted tire traction device control areas.

Six thirty-seconds. At all points. In all major grooves. Not two adjacent grooves at one location — every major groove, everywhere around the tire.

So the same set of tires can be entirely legal on the drive to Trader Joe's and six times short of what the law asks at a gate on Angeles Crest. If you intend to use snow tires instead of carrying chains, 6/32 is the number to measure against, and you measure it in the groove beside a wear bar rather than on one, because 27465(c) excludes tie bars, humps and fillets from the measurement.

What has to be on the car

CVC 27459 is the operating rule:

No person shall operate any motor vehicle, trailer or semitrailer upon any portion of a highway without tire traction devices when that portion of the highway is signed for the requirement of tire traction devices.

For a passenger vehicle or motortruck of 6,000 lb unladen or less, it requires the devices "on at least two drive wheels", and allows the alternative of snow-tread tires on at least two drive wheels where the department or local authority permits. The tires themselves must qualify:

The snow-tread tires shall be of a type and design manufactured for use on snow as a replacement for tire chains or tire traction devices, shall be in good condition, and shall bear the marking of M-S, M/S, or other marking indicating that the tire was manufactured for use on snow

So look for the M+S mark on the sidewall. An all-season tire that does not carry it is not a snow-tread tire for this purpose, whatever the tread pattern looks like.

CVC 27460 is the rule that catches out all-wheel-drive owners. A four-wheel-drive passenger vehicle or motortruck of 6,500 lb unladen or less may run a posted section on snow-tread tires on all four drive wheels — "provided that tire traction devices for at least one set of drive wheels are carried in or upon the vehicle". You still have to have the chains with you. The exemption is from fitting them, not from owning them.

And what counts as a traction device is defined in VEH 605: a device "having a composition and design capable of improving vehicle traction, braking, and cornering ability upon snow or ice-covered surfaces", bearing a permanent impression of the manufacturer's name, initials or trademark and the country of manufacture.

Studded tires: California has a date, and it is not what you think

CVC 27454 otherwise bans metal protuberances beyond the tread. Subdivision (e) carves out studs:

(e)(1) Pneumatic tires containing metal-type studs of tungsten carbide or other suitable material that are inserted or constructed so that under no condition will the number of studs or the percentage of metal in contact with the roadway exceed 3 percent of the total tire area in contact with the roadway, between November 1 and April 30 of each year. A vehicle may be equipped year-round with tires that have studs that retract pneumatically or mechanically when not in use, if the studs are retracted between May 1 and October 31 of each year. A tire on a vehicle shall not be worn to a point at which the studs protrude beyond the tire tread when retracted.

Caltrans states the same window in plain English on its chain-requirements page, and adds the sentence that matters most:

Studded snow tires are permitted in California from November 1 until April 30 each year. During this time, studded tires are permitted in any location within the state. Studded snow tires are not considered tire traction devices and may not be used in lieu of chains.

So studs are a permission, not a solution. They do not get you through a chain control. At sea level in Los Angeles almost nobody needs them, and running them out of season is its own offence.

What this means for a Los Angeles household

Three practical positions, and most people are in the first.

You never drive above the gates. Then none of this applies to you. Buy tires for heat and for the five months of the year when it rains, not for snow. Valley heat against coastal heat is the page for that, and all-season against all-weather against winter tires is the general comparison.

You go up occasionally in winter. Carry chains that fit your car and know how to fit them. That is cheaper than a set of snow tires and it satisfies R-1, R-2 and R-3 in a way nothing else does.

You go up often and want tires instead of chains. Then you need M+S-marked snow-tread tires at 6/32 of an inch at all points in all major grooves, on at least two drive wheels, and if you are relying on the all-wheel-drive route under 27460, a set of chains in the car anyway.

What we do

We supply the tires and fit them at your address, one to four in a visit, wheels up to 22 inches. Before a mountain season we will measure what is on the car against the 6/32 figure rather than the 1/32 one, tell you the number, and say plainly whether the set you have will do the job you are describing. If it will, we will tell you that too and go.

We do not sell tire chains and we do not fit them. We do not fit tires bought elsewhere and we do not sell used tires. Seasonal tire changeover covers swapping a set you already own — we check tread and age on your own off-season set at the visit and tell you if it is finished.

More Los Angeles pages: the California tread law, tire age and when to replace, mobile tire repair, street sweeping and mobile service, and our Los Angeles service area. Find your tire size and how many tires to replace cover the buying decision.

Questions people ask

• Are there really chain controls inside Los Angeles County? Yes. The Caltrans District 7 feed read on 2026-09-20 carried 31 signed control points in Los Angeles County, on SR-2, I-5, SR-14, SR-39 and SR-138, at elevations from 1,026 feet to 6,804 feet.
• What tread depth do snow tires need instead of chains? Six thirty-seconds of an inch at all points in all major grooves, under CVC 27465(b)(3), in a posted tire traction device control area. That is six times the ordinary passenger-car minimum of 1/32 in the city below.
• I have all-wheel drive. Do I still need chains? Under CVC 27460 a four-wheel-drive passenger vehicle or motortruck of 6,500 lb unladen or less may run a posted section on snow-tread tires on all four drive wheels only "provided that tire traction devices for at least one set of drive wheels are carried in or upon the vehicle". So yes, you carry them.
• Do studded tires count as chains? No. Caltrans states it directly: "Studded snow tires are not considered tire traction devices and may not be used in lieu of chains." They are permitted statewide from 1 November to 30 April.
• What do R-1, R-2 and R-3 mean? R-1 requires chains, traction devices or snow tires on the drive axle except for four- or all-wheel-drive vehicles. R-2 requires chains or traction devices on all vehicles except four- or all-wheel drive with snow-treaded tires on all wheels. R-3 requires them on all vehicles, no exceptions.
• Do I need winter tires for driving in Los Angeles itself? No. The snowfall normal at LAX and Burbank is 0.0 inches and all four Los Angeles stations average 0.0 days a year with a maximum at or below freezing. This is a mountain rule.