M+S or Winter tires required in western U.S.?

In CA we have R1 and R2 controls in the winter
R1 4wd with M+S (no chains required) and chains required on 2wd vehicles
R2 Chains required on all vehicles

90% of the time its only R1 in the mountains

so yes if you just carry chains you are good to go. My 19.5s are not M+S so I carry chains

Fargo, you are correct in your assumption.

If your vehicle is over 10,000 and chain up lights are on, you must chain up. In Washington, you must carry chains from Oct date through to April date.

WSDOT winter driving

Dont forget drag chains if your towing!

Yes, the last braking axle must have drag chains.
If you have four wheel drive, you must also carry chains during winter months.

A friend was towing in California during the winter time. There was no snow on the ground. However, he wanted to visit one of the National Parks. Snow chains were required to be available. He had to double back 30miles to buy snow chains despite no snow on the ground.

We camped CA national parks for several years and were checked for chains several times but at Sequoia National Park the ranger checked my tires for M+S in addition to chains. Now, the road there is particularly winding and there was snow on the ground at the time. At Yosemite, was only checked for chains.

After this winter in New England, going back to tires with snowflake symbol at least for winter.

06Fargo wrote:
I did a search of DOT websites.

It appears M+S or winter (mountain-snowflake marked) tires are not required in WA, ID, MT, UT, CA, NV, AZ unless conditions warrant authorities to require them i.e. the "chain up/winter tire lights are on.." or road checks are in place due to conditions...

It appears carrying & installing chains when required on non M+S or winter tires is sufficient.

Please correct if I have this wrong.

Thanks

Correct.

And further broken down by Buzzcut1

When we were enforcing the snow tires/chain laws we do look for the designation on the tires. If you need to be in chains, to be honest you need to be parked. Most times aggressive tread M/S is sufficient. Plus the weight of your truck and camper gives you amazing traction, until you are stopped on an off camber road or driveway.

The biggest problem is the belief the roads should be plowed down to the pavement, which is often not the case out west. Too many car/truck owners have gotten away from the habit of switching out their tires, ahead of the winter season to snow tires. With the advent of All Season Tires much of this habit seems to have gone away. I can't begin to share how many Z rated tires on cars/trucks that we encountered spun out and sometimes wrecked. Many times I just advised the person that they were going to stay right where they slid into, due to their choice or tires and equipment. Your LEOs will have no time or patience for those that have showed up in flip flops, t-shirt and shorts, in a snow storm. So if you are traveling during the winter weather event, come prepared. You might need to shelter one of those wayward "Flip-Flop" drivers, to save their life.

b

I have chains with me all the time...useful for sand and mud especially if 2WD...only needed them once, but I needed them. Travel to LA CA in Nov from Tacoma got stopped in Yreka, no traffic allowed that evening, everyone pulling off...found a side street had dinner watched TV hit the sack up by 0600, road open...only time I have been stopped, BUT always carry chains! Ate breakfast at Black Bear Diner, Mt Shasta...yummy!

We prefer to run snow tires any time there may be chain controls. I don't like to run on bare pavement (sunny or well plowed areas) with chains, and I really don't like to install and remove chains on a single trip. I don't recall the last time I actually had to install chains in a chain control area; snow tires + 4WD are almost always sufficient for me.

To clarify California chain control restrictions (they were stated somewhat incompletely above):

All vehicles (including 4WD) are required to carry chains in chain control areas at all times.

R1: Chains required on drive axle of 2WD vehicles. No chains required for 4WD and no tire restrictions for 4WD (i.e. you could technically use all season tires).

R2: Chains required on drive axle for 2WD vehicles. 4WD vehicles must have snow tires (mountain + snowflake symbol); "Mud+Snow" tires are NOT acceptable.

R3: Chains required on all vehicles. CHP usually closes the road before implementing R3 restrictions.