Winter tires

donn0128 wrote:
Most like Oregon require you to have either winter tires or chains in the mountains after Nov1.

Once winter hits you are required to carry chains on any mountain pass. If towing you need a set for both TV and Trailer.

The original 'snow' tires, commonly used in the American upper midwest, had lots of grooves or edges, and a soft rubber. They improved grip on ice and packed snow, but wore too fast to use year around.

M+S tires are a compromise, hard enough to use year around, but enough traction grooves to handle light snow conditions.

'Knobbly' tires, such as you might see on 4bys, may be good for deep snow, but don't work well on ice or packed snow.

The 'mtn and snow flake' tires use the latest technology to meet winter driving needs. I believe the design specs were pioneered by Canada - government or companies.

Studded tires are another option, but they wear the road. So many states have banned them, or limit their use. Washington state allows them for a limited part of the year, figuring that only those people who regularly cross the mountain passes will use them.

Chains seem to be more common in Western states, but are mostly limited to mountain pass use. But buses and postal vehicles do use them on snowy days in the Seattle area.

We live in Victoria and do not need winter tires, except if we travel 'Up Island' as we have to travel on the 'Malahat', the 1000' high short section of road, as that DOES require winter tires.
Our car, a Mazda 6, has wide, high speed, low profile, all season, tires, which I thought would not allow us to go up Island in the winter. Then I see that they do in fact have the 'M+S' symbol, which amazingly DOES count as a winter tire!
I always thought that an M+S tire had large, knobbly type tread, ours certainly don't!

The BC rules (summary) are here:

http://www.th.gov.bc.ca/popular-topics/faq.htm#winter_tires

If I read that correctly, it's just certain roads that may have sign

“Must Use Winter Tires - M+S or a Tire with the Mountain and Snowflake pictograph on it – October 1st – March 31st“

Or they may have a sign about chains.

That FAQ also lists passes (which are the roads most likely to require the tires or chains.

Most of the western states DOTs have similar winter tire information.

http://www.wsdot.com/winter/traction.htm
Washington, for example, has 'traction tire' advisories for certain mountain roads - not all the time, just when conditions are bad. And may require chains on larger vehicles. Some states require carrying chains (or equivalent) on mountain roads, depending on vehicle size.

http://www.mdt.mt.gov/travinfo/tire_restrictions.shtml
Montana lets the tire dealer do the selling.

Oregon TripCheck on traction tires and chains

Most like Oregon require you to have either winter tires or chains in the mountains after Nov1.

Sorry I can't answer your question, but my guess is that no state requires winter tires. They are optional in every state I have lived in (quite a few). There are dates before and after which studded snow tires are not allowed, however. There are also locations in the mountains where chains may be required under certain winter conditions.