Shall I risk ridicule by jumping in with my ha'penny worth here? Oh well, why not.
My knowledge base is quite old but I suspect still largely relevant. Back in the '60s/early '70s, when I worked for Firestone, I got involved in testing tyres on Beach buggies. There had been a number of high profile road accidents involving them and several seemed to have been running on our tyres. The problem was that there was a big image thing going on with beach buggies in Britain because of images in magazines and from machines which appeared in films. They generally tried to get the widest tyres possible which were often part worn racing tyres, often ex F1 which were maybe 4 or 5 times as wide as a road tyre at that time and, even when new, had much less tread depth than a road tyre. Here's the very famous one from The Thomas Crown Affair which actually had a Corvair flat 6 in the back with in excess of 200hp.
https://www.youtube.com/watch?v=N6vogI1JZZg
considering the power the tyres aren't actually too wild. I saw the film 3 times just to see the Dune Buggy! Here's a road going one with some pretty wide ones fitted. fine in the dry Californian sunshine, not so good on a wet day down the Kings Road!
https://www.youtube.com/watch?v=X66Ei8kIIIc
and just look at the width of those rear tyres. The weight of a beach buggy is not great so when you put something as wide as that on it you can confidently predict, even before you try it out, that it's going to aquaplane at the slightest excuse, and, of course this is what we found. - and we had a really fun week of cavorting around at Chobham on the skid pan with a couple of beach buggies and other vehicles. Then there was the problem that a race tyre is very lightly constructed so sidewall damage is easily inflicted. Basically they are unsuitable for use on the public highway. So we fulfilled the brief we had been given which was to verify that racing tyres should not be used - and in fact not just on beach buggies but on the public highway in general on any vehicle.
There was an awful lot more to it than I've detailed above and the end report was well received by our management and some others that it was decided to look at what would work most safely. The big problem was getting the tyre to engage with the road surface on such a light vehicle and especially when the surface was wet. The first thing is that you don't really want a very wide tyre in the wet, or in the snow for that matter. Ice is a whole different problem because it precludes any possibility of engaging with the road surface. Best option on ice is to use a studded tyre, but this is a very specialized, expensive and, in our climate, not often usable option (lots of people tearing around on tarmac roads with studded tyres soon causes horrific damage to the road surface - You need solid ice) so if you are not going to use studs you need very sophisticated, specialized, - "soft" in simple language - tread compounds which will, to some extent, engage with ice. The trouble is if you then run these on dry roads they wear out very very quickly. So, it's very difficult to address the problem of what best to do for really icy roads in our country (UK). There's no substitute for just proceeding slowly and driving very smoothly- Ca' Canny we'd say, eh jim?
Snow and wet surfaces are a more easily addressed - but not "easy" problem. I'm not a snow specialist, but a lot of sensible "stuff" about letting trapped snow in the tyre engage with the snow on the road. The snow in the tyre bonding to the snow on the ground then lets the tyre "climb" along the snow trapped in the tread a bit like a rack and pinion railway train. If you are going to let this work well though you need to reduce wheelspin to as near zero as makes no difference and I'm sure many people will have seen and/or experienced how pointless it is to spin the wheels in snow - you end up going nowhere!
Then we come to wet surfaces. Cleverly compounded "sticky" tread rubber is a big help here but will wear more quickly than a summer tyre's harder wearing compounds. But the tread pattern is very important to try to get the water out of the way and let the rubber engage with the road surface. One of the first "clever" designs, which worked quite well - you often saw them on Jags and Aston Martins etc - was the Dunlop Aquajet back in the late '60's which had lots of voids in the tread design to disperse water and also had the "aquajets" in the shoulder area to "pump" the water out. You can see them here quite clearly:
https://www.vintagetyres.com/shop/dunlop-sp-sport-aquajet-165-70r10-72s
Do you know when Nokian took out their patent dave? Anyway, when you then start thinking about how best to get the tread of the tyre into reasonably dry contact with the road surface it boils down to two main techniques. Large grooves in the rubber surface to shift the main body of the water and much smaller slits - sipes - which, once the main volume of water has been shifted, "squeegees" most of the remaining dampness under the individual tread blocks up and retains it until the tyre revolves and lets the water come back out again by centrifugal action. The big problem with moving most of the water is that as the tread contact surface rotates down into contact with the water the water on the outside can easily shoot out sideways but the water in the middle has nowhere to go. This is why a slick (without tread pattern) racing tyre - or bald/nearly bald - road tyre will skid (aquaplane) even on just a damp surface. The water can't get out from under the contact patch on the tyre in the time available - gets worse the faster you are going - so it completely looses contact with the road surface and the car will behave like it's on ice!
So now look at this modern tyre which is designed to do it's best to get over the problem;
https://www.avontyres.com/en-gb/tyres/avon-as7
It's got a sophisticated compound of rubber used in the tread layer and a very aggressive tread pattern with lots of grooves to allow water to escape from the middle of the contact patch and smaller sipes to shift the little bit left. But more than that, you'll notice the tread pattern is arranged in a "V" isn't it? Think about that for a moment. The big problem area for shifting the water is to get it away from the centre of the contact patch. Think about how this tread pattern is presenting to the road. Consider just the one "V" element of the pattern. The water in the middle of the contact patch is going to be influenced by the point of the "V" first. Then, as the tyre continues to rotate, contact between the tyre and the road is going to squeeze the water outwards along the arms of the "V" until it reaches the outside shoulder of the tread. This design is much more efficient at shifting the water than a conventional "block" tread pattern like this one:
https://www.avontyres.com/en-gb/tyres/avon-zv7
Which will actually stop water moving outwards and rely on being able to move the water front to rear through the tread grooves. This design will become much less efficient as the tyre ages and the groove depth decreases.
However the last example will be a much better tyre to drive fast on when the road is dry because it's tread is much more stable. Compare it with the all weather design and you can see the tread is less well braced and will tend to "squirm" if you push it hard on a dry road surface.
Sure I've not mentioned half of it but maybe this will give some of you cause to comment or call me out?
