Time for Hammer's Winter Driving Tips

I've done this several times, but it's been a bit and it is that time of year.

Here's one of the older threads, and I can't promise I won't repeat myself!
Winter Driving w/o the platitudes.

This won't be as long as I'm on the phone instead of laptop.


Probably the most important thing to remember is that your tires traction limits in one direction effects the limits in the others. So if you're using all your traction to accelerate, there's not any traction left for lateral stability or cornering. Or vice versa. That's something we all know from the seat of our pants, even if we don't understand it in exactly those terms. We all know how a hard accelerating or breaking vehicle feels a bit squirrel, and that is why. You've used up most of the tires available traction.

So if you remember this, you can use it to your advantage, and limit what you ask of your tires in the directions you don't need at the moment. So minimal accel/decel when you need to corner, and as little turning as possible when it's time to stop or start.

Which reminds me of another critical point, neutral throttle. That's not zero throttle, that's the point at which engine putting zero input into the tires. And that's important to know because the most stable state of a truck and trailer is at or just slightly above neutral throttle. At that power setting, there is either no load or a very slight pull at the kingpin. You'll likely still be decelerating at that setting. But this eliminates the truck or trailer from introducing forces into the other that would require traction to overcome. It's a much more stable condition than coasting, where the trailer is pushing the truck with the kingpin. As this guy found out :

And I think I'll leave there for now... Pizza and adult refreshments are calling!

 

A bit touchy, are we? You happen to notice I didn't mention the name on the truck, because it didn't matter. I believe the search terms I used were "truck jackknifes on icy bridge." This was the video I was hoping to find, but I couldn't have told you the name on the truck. I only knew it as a prime example of what not to do.

Watch that video again. (Sorry, only the first clip of the video. My bad!) You can see the headlights dip as the driver jumped off the throttle. It's pretty #### obvious that that action caused the drives to start sliding once he hit the icy bridge. By going to no throttle he demanded more traction than the drives could provide, causing that slide (you can plainly see the truck jump when the drives try to regain traction once he hits wet pavement again.) Had he gone to neutral throttle he would have just coasted across there with no issues. And quite frankly, while I didn't intend for the blue pickup to be part of this discussion, had he followed my advice, he'd have coasted right across there without spinning as he did. So I actually [GASP] DID pick a video that demonstrated exactly what I needed it to.

This is one of my biggest pet peeves with what comes out of safety departments across this industry. "SLOW DOWN!" is their answer for every situation, when there are very definitely situations where slowing is not the correct answer. Now one could argue that driver should have been going slower, but he'd have been just as far out of shape had he been traveling half that speed and had the same response.

 

It's all about maximizing your available traction. If you are not using any to accelerate or decelerate, every little bit you have can be used to maintain the trucks path. And on something with a near zero coefficient of friction like wet ice, it could well be the difference between going on down the road and exploring the ditch.